| Message ID | 20190710133917.1188-1-acgoide@tycho.nsa.gov (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | selinux-testsuite: add tests for fsnotify | expand |
On 7/10/19 9:39 AM, Aaron Goidel wrote: > Added a suite to test permissions for setting inotify and fanotify watches > on filesystem objects. Tests watch, watch_with_perm, and watch_reads permissions. > > Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> To exercise these tests you must do the following: 1) Apply the kernel patch adding the checks 2) Define the new permissions in your base policy, which you can do as follows: - Extract the base module: semodule -c -E base - Edit the common file definition in base.cil to include the watch permissions: (common file (ioctl read write create getattr setattr lock relabelfrom relabelto append map unlink link rename execute swapon quotaon mounton watch watch_with_perm watch_reads )) - Insert modified base module: semodule -i base.cil NB at this point, SELinux will start enforcing the watch permissions and you may experience denials. You may choose to allow the watch permissions to existing domains or switch to permissive when booting to avoid failures. 3) Define the new permissions in your policy development headers, which you can do as follows: - cd /usr/share/selinux/devel/include/support - Add the watch permissions to all file perms in all_perms.spt: define(`all_file_perms',`{ ioctl read write create getattr setattr lock relabelfrom relabelto append map unlink link rename execute swapon quotaon mounton watch watch_with_perm watch_reads execute_no_trans entrypoint execmod open audit_access }') 4) Build and run the test suite > --- > policy/Makefile | 4 ++ > policy/test_notify.te | 74 ++++++++++++++++++++++++ > tests/Makefile | 4 ++ > tests/notify/Makefile | 5 ++ > tests/notify/test | 101 +++++++++++++++++++++++++++++++++ > tests/notify/test_fanotify.c | 105 +++++++++++++++++++++++++++++++++++ > tests/notify/test_inotify.c | 43 ++++++++++++++ > 7 files changed, 336 insertions(+) > create mode 100644 policy/test_notify.te > create mode 100644 tests/notify/Makefile > create mode 100755 tests/notify/test > create mode 100644 tests/notify/test_fanotify.c > create mode 100644 tests/notify/test_inotify.c > > diff --git a/policy/Makefile b/policy/Makefile > index 305b572..65f88c5 100644 > --- a/policy/Makefile > +++ b/policy/Makefile > @@ -71,6 +71,10 @@ ifeq ($(shell grep -q corenet_sctp_bind_all_nodes $(POLDEV)/include/kernel/coren > TARGETS += test_sctp.te > endif > > +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) > +TARGETS+=test_notify.te > +endif > + > ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) > TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te, $(TARGETS)) > endif > diff --git a/policy/test_notify.te b/policy/test_notify.te > new file mode 100644 > index 0000000..8ba6f1a > --- /dev/null > +++ b/policy/test_notify.te > @@ -0,0 +1,74 @@ > +#################################################### > +# Policy for testing inoftify and fanotify watches # > +#################################################### > + > +attribute test_notify_domain; > + > +# Type for the file on which we want to set a watch > +type test_notify_file_t; > +files_type(test_notify_file_t); > + > +# Domain for the process which CAN set a non-permission watch > +type test_watch_t; > +domain_type(test_watch_t); > +unconfined_runs_test(test_watch_t); > + > +typeattribute test_watch_t test_notify_domain; > +typeattribute test_watch_t testdomain; > + > +allow test_notify_domain self:capability sys_admin; > + > +allow test_watch_t test_notify_file_t:file { read write open watch }; > + > +# Domain for the process which CAN set a NON-access watch on a file > +type test_perm_watch_t; > +domain_type(test_perm_watch_t); > +unconfined_runs_test(test_perm_watch_t); > + > +typeattribute test_perm_watch_t test_notify_domain; > +typeattribute test_perm_watch_t testdomain; > + > +allow test_perm_watch_t test_notify_file_t:file { read write open watch watch_with_perm }; > + > +# Domain which CAN set a NON-perm watch which MAY read accesses > +type test_read_watch_t; > +domain_type(test_read_watch_t); > +unconfined_runs_test(test_read_watch_t); > + > +typeattribute test_read_watch_t test_notify_domain; > +typeattribute test_read_watch_t testdomain; > + > +allow test_read_watch_t test_notify_file_t:file { read write open watch watch_reads }; > + > +# Domain which CAN set any watch which CAN read accesses > +type test_perm_read_watch_t; > +domain_type(test_perm_read_watch_t); > +unconfined_runs_test(test_perm_read_watch_t); > + > +typeattribute test_perm_read_watch_t test_notify_domain; > +typeattribute test_perm_read_watch_t testdomain; > + > +allow test_perm_read_watch_t test_notify_file_t:file { read write open watch watch_with_perm watch_reads }; > + > +# Domain which CANNOT set any watches > +type test_no_watch_t; > +domain_type(test_no_watch_t); > +unconfined_runs_test(test_no_watch_t); > + > +typeattribute test_no_watch_t test_notify_domain; > +typeattribute test_no_watch_t testdomain; > + > +allow test_no_watch_t test_notify_file_t:file { read write open }; > + > +# Domain which has no write access but can watch > +type test_rdonly_t; > +domain_type(test_rdonly_t); > +unconfined_runs_test(test_rdonly_t); > + > +typeattribute test_rdonly_t test_notify_domain; > +typeattribute test_rdonly_t testdomain; > + > +allow test_rdonly_t test_notify_file_t:file { read open watch }; > + > +miscfiles_domain_entry_test_files(test_notify_domain); > +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); > diff --git a/tests/Makefile b/tests/Makefile > index 63aa325..b99c96e 100644 > --- a/tests/Makefile > +++ b/tests/Makefile > @@ -50,6 +50,10 @@ ifeq ($(shell grep "^SELINUX_INFINIBAND_PKEY_TEST=" infiniband_pkey/ibpkey_test. > SUBDIRS += infiniband_pkey > endif > > +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) > +SUBDIRS+=notify > +endif > + > ifeq ($(DISTRO),RHEL4) > SUBDIRS:=$(filter-out bounds dyntrace dyntrans inet_socket mmap nnp_nosuid overlay unix_socket, $(SUBDIRS)) > endif > diff --git a/tests/notify/Makefile b/tests/notify/Makefile > new file mode 100644 > index 0000000..78c4b3b > --- /dev/null > +++ b/tests/notify/Makefile > @@ -0,0 +1,5 @@ > +TARGETS=test_inotify test_fanotify > + > +all: $(TARGETS) > +clean: > + rm -f $(TARGETS) > diff --git a/tests/notify/test b/tests/notify/test > new file mode 100755 > index 0000000..21f03de > --- /dev/null > +++ b/tests/notify/test > @@ -0,0 +1,101 @@ > +#!/usr/bin/perl > + > +use Test; > +BEGIN { plan tests => 14 } # number of tests to run > + > +# help the test script locate itself > +$basedir = $0; > +$basedir =~ s|(.*)/[^/]*|$1|; > + > +# Get rid of a testfile from last run if it's there (just in case) > +system("rm -f $basedir/watch_me"); > + > +# Create a new test file > +system("touch $basedir/watch_me"); > +system("chcon -t test_notify_file_t $basedir/watch_me"); > + > +## TESTS > + > +## TEST BASIC WATCH PERMISSION > +# Should be able to set inotify watch > +$exit_val = > + system("runcon -t test_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); > +ok( $exit_val, 0 ); > + > +# Should be able to set non-permissions based fanotify watch > +$exit_val = system( > + "runcon -t test_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); > +ok( $exit_val, 0 ); > + > +# Should NOT be able to set permission based fanotify watch > +$exit_val = system( > + "runcon -t test_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1"); > +ok($exit_val); # this should fail > + > +# Should NOT be able to set read based fanotify watch > +$exit_val = system( > + "runcon -t test_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1"); > +ok($exit_val); # this should fail > + > +# Should NOT be able to set read based inotify watch > +$exit_val = system( > + "runcon -t test_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1"); > +ok($exit_val); # this should fail > + > +## TEST PERM WATCH > +# Should be able to set permission based fanotify watch > +$exit_val = system( > +"runcon -t test_perm_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1" > +); > +ok( $exit_val, 0 ); > + > +# Should NOT be able to set watch of accesses > +$exit_val = system( > +"runcon -t test_perm_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1" > +); > +ok($exit_val); # this should fail > + > +## TEST READ NO PERM WATCH PERMSISSIONS > +# Should NOT be able to set read and perm watch > +$exit_val = system( > +"runcon -t test_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" > +); > +ok($exit_val); # should fail > + > +# Should be able to set read inotify watch > +$exit_val = system( > +"runcon -t test_read_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1" > +); > +ok( $exit_val, 0 ); > + > +## TEST READ WITH PERM WATCH PERMSISSIONS > +# Should be able to set read and perm watch > +$exit_val = system( > +"runcon -t test_perm_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" > +); > +ok( $exit_val, 0 ); > + > +## TEST NO WATCH PERMSISSIONS > +# Should NOT be able to set inotify watch > +$exit_val = system( > + "runcon -t test_no_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); > +ok($exit_val); # this should fail > + > +# Should NOT be able to set any fanotify watch > +$exit_val = system( > + "runcon -t test_no_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); > +ok($exit_val); # this should fail > + > +## TEST READ ONLY > +# Should NOT be able to get read-write descriptor > +$exit_val = system( > + "runcon -t test_rdonly_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); > +ok($exit_val); # this should fail > + > +# Should be able to get read-write descriptor > +$exit_val = system( > + "runcon -t test_watch_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); > +ok( $exit_val, 0 ); > + > +# Clean up test file > +system("rm -f $basedir/watch_me"); > diff --git a/tests/notify/test_fanotify.c b/tests/notify/test_fanotify.c > new file mode 100644 > index 0000000..fff773f > --- /dev/null > +++ b/tests/notify/test_fanotify.c > @@ -0,0 +1,105 @@ > +#define _GNU_SOURCE 1 > + > +#include <stdio.h> > +#include <stdlib.h> > + > +#include <getopt.h> > + > +#include <fcntl.h> > +#include <poll.h> > +#include <sys/fanotify.h> > +#include <unistd.h> > + > +void printUsage() > +{ > + fprintf(stderr, "Usage: test_fanotify [-p] [-r] [-l] file_name\n"); > + exit(1); > +} > + > +int main(int argc, char *argv[]) > +{ > + if (argc < 2) { > + printUsage(); > + } > + > + int fd, ret, arg; > + int mask = FAN_OPEN; // default mask > + int listening = 0; > + > + // the -p flag will test for watch_with_perm > + // the mask used at mark will contain FAN_OPEN_PERM > + // > + // the -r flag will test for watching accesses to files for reads > + // the mask will contain FAN_ACCESS > + while ((arg = getopt(argc, argv, "prl")) != -1) { > + switch (arg) { > + case 'p': > + mask |= FAN_OPEN_PERM; > + break; > + case 'r': > + mask |= FAN_ACCESS; > + break; > + case 'l': > + listening = 1; > + break; > + default: > + printUsage(); > + } > + } > + > + // get file descriptor for new fanotify event queue > + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); > + if (fd < 0) { > + perror("fanotify_init:bad file descriptor"); > + exit(1); > + } > + > + // mark a filesystem object and add mark to event queue > + // get notifications on file opens, accesses, and closes > + // use current working directory as base dir > + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, AT_FDCWD, argv[optind]); > + > + if (ret < 0) { > + perror("test_fanotify:watch denied"); > + exit(1); > + } > + > + // logic to actually listen for an event if the -l flag is passed > + // this is used to test if an app with read-only access can get a read/write > + // handle to the watched file > + if (listening) { > + if (fork() == 0) { // fork a child process to cause an event on the file > + FILE *f; > + > + f = fopen(argv[optind], "r"); // open file for reading > + fgetc(f); // read char from file > + > + fclose(f); > + } else { // logic to watch for events and try to access file read/write > + struct pollfd fds; > + fds.fd = fd; > + fds.events = POLLIN; > + > + while (listening) { > + int polled = poll(&fds, 1, 1); > + if (polled > 0) { > + if (fds.revents & POLLIN) { > + struct fanotify_event_metadata buff[200]; > + > + size_t len = read(fd, (void *)&buff, sizeof(buff)); > + if (len == -1) { > + perror("test_fanotify:can't open file"); > + exit(1); > + } else { > + listening = 0; > + break; > + } > + } > + } else if (polled == -1) { > + listening = 0; > + } > + } > + } > + } > + exit(0); > +} > diff --git a/tests/notify/test_inotify.c b/tests/notify/test_inotify.c > new file mode 100644 > index 0000000..17c3565 > --- /dev/null > +++ b/tests/notify/test_inotify.c > @@ -0,0 +1,43 @@ > +#include <stdio.h> > +#include <stdlib.h> > +#include <sys/inotify.h> > +#include <getopt.h> > + > +int main(int argc, char *argv[]) > +{ > + if (argc < 2) { > + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); > + exit(1); > + } > + > + int fd, wd, arg; > + int mask = IN_MODIFY; > + > + while ((arg = getopt(argc, argv, "pr")) != -1) { > + switch (arg) { > + case 'r': > + mask |= IN_ACCESS; > + break; > + default: > + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); > + exit(1); > + } > + } > + > + // get new file descriptor for inotify access > + fd = inotify_init(); > + if (fd < 0) { > + perror("inotify_init:bad file descriptor"); > + exit(1); > + } > + > + // set watch on file and get watch descriptor for accessing events on it > + wd = inotify_add_watch(fd, argv[optind], mask); > + > + if (wd < 0) { > + perror("test_inotify:watch denied"); > + exit(1); > + } > + > + exit(0); > +} >
On Wed, Jul 10, 2019 at 9:40 AM Aaron Goidel <acgoide@tycho.nsa.gov> wrote: > > Added a suite to test permissions for setting inotify and fanotify watches > on filesystem objects. Tests watch, watch_with_perm, and watch_reads permissions. > > Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> > --- > policy/Makefile | 4 ++ > policy/test_notify.te | 74 ++++++++++++++++++++++++ > tests/Makefile | 4 ++ > tests/notify/Makefile | 5 ++ > tests/notify/test | 101 +++++++++++++++++++++++++++++++++ > tests/notify/test_fanotify.c | 105 +++++++++++++++++++++++++++++++++++ > tests/notify/test_inotify.c | 43 ++++++++++++++ > 7 files changed, 336 insertions(+) > create mode 100644 policy/test_notify.te > create mode 100644 tests/notify/Makefile > create mode 100755 tests/notify/test > create mode 100644 tests/notify/test_fanotify.c > create mode 100644 tests/notify/test_inotify.c FYI, I'm still waiting on the new permissions to show up in the Rawhide policy so I can test this and verify everything is working correctly with a "released" policy. I also had to perform a number of fixes to get 'make check-syntax' to run cleanly.
On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: > Added a suite to test permissions for setting inotify and fanotify watches > on filesystem objects. Tests watch, watch_with_perm, and watch_reads permissions. Ive also "tested" the fsnotify patch. And my tests indicate that this might cause issues: I added the access vectors to my policy, but on older systems (debian 10) cron fails to start cron needs the "entrypoint" permission on /etc/crontab but it looks like appending the "watch" access vectors to common-file disrupted the ordering The result is that now i have to allow cron to "watch_read" /etc/crontab even though the neither kernel nor selinux user space are aware of the fsnotify access vectors It seems the cron selinux code got confused and now thinks watch_read is entrypoint (its using selinux code to determine whether it can manually transition to cronjob domains on crontabs) I am hoping this issue with resolve itself on systems with kernels and user spaces that suppose fsnotify. However unless i am overlooking something this is still likely to disrupt compatibility > > Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> > --- > policy/Makefile | 4 ++ > policy/test_notify.te | 74 ++++++++++++++++++++++++ > tests/Makefile | 4 ++ > tests/notify/Makefile | 5 ++ > tests/notify/test | 101 +++++++++++++++++++++++++++++++++ > tests/notify/test_fanotify.c | 105 +++++++++++++++++++++++++++++++++++ > tests/notify/test_inotify.c | 43 ++++++++++++++ > 7 files changed, 336 insertions(+) > create mode 100644 policy/test_notify.te > create mode 100644 tests/notify/Makefile > create mode 100755 tests/notify/test > create mode 100644 tests/notify/test_fanotify.c > create mode 100644 tests/notify/test_inotify.c > > diff --git a/policy/Makefile b/policy/Makefile > index 305b572..65f88c5 100644 > --- a/policy/Makefile > +++ b/policy/Makefile > @@ -71,6 +71,10 @@ ifeq ($(shell grep -q corenet_sctp_bind_all_nodes $(POLDEV)/include/kernel/coren > TARGETS += test_sctp.te > endif > > +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) > +TARGETS+=test_notify.te > +endif > + > ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) > TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te, $(TARGETS)) > endif > diff --git a/policy/test_notify.te b/policy/test_notify.te > new file mode 100644 > index 0000000..8ba6f1a > --- /dev/null > +++ b/policy/test_notify.te > @@ -0,0 +1,74 @@ > +#################################################### > +# Policy for testing inoftify and fanotify watches # > +#################################################### > + > +attribute test_notify_domain; > + > +# Type for the file on which we want to set a watch > +type test_notify_file_t; > +files_type(test_notify_file_t); > + > +# Domain for the process which CAN set a non-permission watch > +type test_watch_t; > +domain_type(test_watch_t); > +unconfined_runs_test(test_watch_t); > + > +typeattribute test_watch_t test_notify_domain; > +typeattribute test_watch_t testdomain; > + > +allow test_notify_domain self:capability sys_admin; > + > +allow test_watch_t test_notify_file_t:file { read write open watch }; > + > +# Domain for the process which CAN set a NON-access watch on a file > +type test_perm_watch_t; > +domain_type(test_perm_watch_t); > +unconfined_runs_test(test_perm_watch_t); > + > +typeattribute test_perm_watch_t test_notify_domain; > +typeattribute test_perm_watch_t testdomain; > + > +allow test_perm_watch_t test_notify_file_t:file { read write open watch watch_with_perm }; > + > +# Domain which CAN set a NON-perm watch which MAY read accesses > +type test_read_watch_t; > +domain_type(test_read_watch_t); > +unconfined_runs_test(test_read_watch_t); > + > +typeattribute test_read_watch_t test_notify_domain; > +typeattribute test_read_watch_t testdomain; > + > +allow test_read_watch_t test_notify_file_t:file { read write open watch watch_reads }; > + > +# Domain which CAN set any watch which CAN read accesses > +type test_perm_read_watch_t; > +domain_type(test_perm_read_watch_t); > +unconfined_runs_test(test_perm_read_watch_t); > + > +typeattribute test_perm_read_watch_t test_notify_domain; > +typeattribute test_perm_read_watch_t testdomain; > + > +allow test_perm_read_watch_t test_notify_file_t:file { read write open watch watch_with_perm watch_reads }; > + > +# Domain which CANNOT set any watches > +type test_no_watch_t; > +domain_type(test_no_watch_t); > +unconfined_runs_test(test_no_watch_t); > + > +typeattribute test_no_watch_t test_notify_domain; > +typeattribute test_no_watch_t testdomain; > + > +allow test_no_watch_t test_notify_file_t:file { read write open }; > + > +# Domain which has no write access but can watch > +type test_rdonly_t; > +domain_type(test_rdonly_t); > +unconfined_runs_test(test_rdonly_t); > + > +typeattribute test_rdonly_t test_notify_domain; > +typeattribute test_rdonly_t testdomain; > + > +allow test_rdonly_t test_notify_file_t:file { read open watch }; > + > +miscfiles_domain_entry_test_files(test_notify_domain); > +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); > diff --git a/tests/Makefile b/tests/Makefile > index 63aa325..b99c96e 100644 > --- a/tests/Makefile > +++ b/tests/Makefile > @@ -50,6 +50,10 @@ ifeq ($(shell grep "^SELINUX_INFINIBAND_PKEY_TEST=" infiniband_pkey/ibpkey_test. > SUBDIRS += infiniband_pkey > endif > > +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) > +SUBDIRS+=notify > +endif > + > ifeq ($(DISTRO),RHEL4) > SUBDIRS:=$(filter-out bounds dyntrace dyntrans inet_socket mmap nnp_nosuid overlay unix_socket, $(SUBDIRS)) > endif > diff --git a/tests/notify/Makefile b/tests/notify/Makefile > new file mode 100644 > index 0000000..78c4b3b > --- /dev/null > +++ b/tests/notify/Makefile > @@ -0,0 +1,5 @@ > +TARGETS=test_inotify test_fanotify > + > +all: $(TARGETS) > +clean: > + rm -f $(TARGETS) > diff --git a/tests/notify/test b/tests/notify/test > new file mode 100755 > index 0000000..21f03de > --- /dev/null > +++ b/tests/notify/test > @@ -0,0 +1,101 @@ > +#!/usr/bin/perl > + > +use Test; > +BEGIN { plan tests => 14 } # number of tests to run > + > +# help the test script locate itself > +$basedir = $0; > +$basedir =~ s|(.*)/[^/]*|$1|; > + > +# Get rid of a testfile from last run if it's there (just in case) > +system("rm -f $basedir/watch_me"); > + > +# Create a new test file > +system("touch $basedir/watch_me"); > +system("chcon -t test_notify_file_t $basedir/watch_me"); > + > +## TESTS > + > +## TEST BASIC WATCH PERMISSION > +# Should be able to set inotify watch > +$exit_val = > + system("runcon -t test_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); > +ok( $exit_val, 0 ); > + > +# Should be able to set non-permissions based fanotify watch > +$exit_val = system( > + "runcon -t test_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); > +ok( $exit_val, 0 ); > + > +# Should NOT be able to set permission based fanotify watch > +$exit_val = system( > + "runcon -t test_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1"); > +ok($exit_val); # this should fail > + > +# Should NOT be able to set read based fanotify watch > +$exit_val = system( > + "runcon -t test_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1"); > +ok($exit_val); # this should fail > + > +# Should NOT be able to set read based inotify watch > +$exit_val = system( > + "runcon -t test_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1"); > +ok($exit_val); # this should fail > + > +## TEST PERM WATCH > +# Should be able to set permission based fanotify watch > +$exit_val = system( > +"runcon -t test_perm_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1" > +); > +ok( $exit_val, 0 ); > + > +# Should NOT be able to set watch of accesses > +$exit_val = system( > +"runcon -t test_perm_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1" > +); > +ok($exit_val); # this should fail > + > +## TEST READ NO PERM WATCH PERMSISSIONS > +# Should NOT be able to set read and perm watch > +$exit_val = system( > +"runcon -t test_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" > +); > +ok($exit_val); # should fail > + > +# Should be able to set read inotify watch > +$exit_val = system( > +"runcon -t test_read_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1" > +); > +ok( $exit_val, 0 ); > + > +## TEST READ WITH PERM WATCH PERMSISSIONS > +# Should be able to set read and perm watch > +$exit_val = system( > +"runcon -t test_perm_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" > +); > +ok( $exit_val, 0 ); > + > +## TEST NO WATCH PERMSISSIONS > +# Should NOT be able to set inotify watch > +$exit_val = system( > + "runcon -t test_no_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); > +ok($exit_val); # this should fail > + > +# Should NOT be able to set any fanotify watch > +$exit_val = system( > + "runcon -t test_no_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); > +ok($exit_val); # this should fail > + > +## TEST READ ONLY > +# Should NOT be able to get read-write descriptor > +$exit_val = system( > + "runcon -t test_rdonly_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); > +ok($exit_val); # this should fail > + > +# Should be able to get read-write descriptor > +$exit_val = system( > + "runcon -t test_watch_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); > +ok( $exit_val, 0 ); > + > +# Clean up test file > +system("rm -f $basedir/watch_me"); > diff --git a/tests/notify/test_fanotify.c b/tests/notify/test_fanotify.c > new file mode 100644 > index 0000000..fff773f > --- /dev/null > +++ b/tests/notify/test_fanotify.c > @@ -0,0 +1,105 @@ > +#define _GNU_SOURCE 1 > + > +#include <stdio.h> > +#include <stdlib.h> > + > +#include <getopt.h> > + > +#include <fcntl.h> > +#include <poll.h> > +#include <sys/fanotify.h> > +#include <unistd.h> > + > +void printUsage() > +{ > + fprintf(stderr, "Usage: test_fanotify [-p] [-r] [-l] file_name\n"); > + exit(1); > +} > + > +int main(int argc, char *argv[]) > +{ > + if (argc < 2) { > + printUsage(); > + } > + > + int fd, ret, arg; > + int mask = FAN_OPEN; // default mask > + int listening = 0; > + > + // the -p flag will test for watch_with_perm > + // the mask used at mark will contain FAN_OPEN_PERM > + // > + // the -r flag will test for watching accesses to files for reads > + // the mask will contain FAN_ACCESS > + while ((arg = getopt(argc, argv, "prl")) != -1) { > + switch (arg) { > + case 'p': > + mask |= FAN_OPEN_PERM; > + break; > + case 'r': > + mask |= FAN_ACCESS; > + break; > + case 'l': > + listening = 1; > + break; > + default: > + printUsage(); > + } > + } > + > + // get file descriptor for new fanotify event queue > + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); > + if (fd < 0) { > + perror("fanotify_init:bad file descriptor"); > + exit(1); > + } > + > + // mark a filesystem object and add mark to event queue > + // get notifications on file opens, accesses, and closes > + // use current working directory as base dir > + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, AT_FDCWD, argv[optind]); > + > + if (ret < 0) { > + perror("test_fanotify:watch denied"); > + exit(1); > + } > + > + // logic to actually listen for an event if the -l flag is passed > + // this is used to test if an app with read-only access can get a read/write > + // handle to the watched file > + if (listening) { > + if (fork() == 0) { // fork a child process to cause an event on the file > + FILE *f; > + > + f = fopen(argv[optind], "r"); // open file for reading > + fgetc(f); // read char from file > + > + fclose(f); > + } else { // logic to watch for events and try to access file read/write > + struct pollfd fds; > + fds.fd = fd; > + fds.events = POLLIN; > + > + while (listening) { > + int polled = poll(&fds, 1, 1); > + if (polled > 0) { > + if (fds.revents & POLLIN) { > + struct fanotify_event_metadata buff[200]; > + > + size_t len = read(fd, (void *)&buff, sizeof(buff)); > + if (len == -1) { > + perror("test_fanotify:can't open file"); > + exit(1); > + } else { > + listening = 0; > + break; > + } > + } > + } else if (polled == -1) { > + listening = 0; > + } > + } > + } > + } > + exit(0); > +} > diff --git a/tests/notify/test_inotify.c b/tests/notify/test_inotify.c > new file mode 100644 > index 0000000..17c3565 > --- /dev/null > +++ b/tests/notify/test_inotify.c > @@ -0,0 +1,43 @@ > +#include <stdio.h> > +#include <stdlib.h> > +#include <sys/inotify.h> > +#include <getopt.h> > + > +int main(int argc, char *argv[]) > +{ > + if (argc < 2) { > + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); > + exit(1); > + } > + > + int fd, wd, arg; > + int mask = IN_MODIFY; > + > + while ((arg = getopt(argc, argv, "pr")) != -1) { > + switch (arg) { > + case 'r': > + mask |= IN_ACCESS; > + break; > + default: > + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); > + exit(1); > + } > + } > + > + // get new file descriptor for inotify access > + fd = inotify_init(); > + if (fd < 0) { > + perror("inotify_init:bad file descriptor"); > + exit(1); > + } > + > + // set watch on file and get watch descriptor for accessing events on it > + wd = inotify_add_watch(fd, argv[optind], mask); > + > + if (wd < 0) { > + perror("test_inotify:watch denied"); > + exit(1); > + } > + > + exit(0); > +} > -- > 2.21.0 >
On 9/10/19 1:59 AM, Dominick Grift wrote: > On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: >> Added a suite to test permissions for setting inotify and fanotify watches >> on filesystem objects. Tests watch, watch_with_perm, and watch_reads permissions. > > Ive also "tested" the fsnotify patch. And my tests indicate that this might cause issues: > > I added the access vectors to my policy, but on older systems (debian 10) cron fails to start > cron needs the "entrypoint" permission on /etc/crontab but it looks like appending the "watch" access vectors to common-file disrupted the ordering > The result is that now i have to allow cron to "watch_read" /etc/crontab even though the neither kernel nor selinux user space are aware of the fsnotify access vectors > It seems the cron selinux code got confused and now thinks watch_read is entrypoint (its using selinux code to determine whether it can manually transition to cronjob domains on crontabs) > > I am hoping this issue with resolve itself on systems with kernels and user spaces that suppose fsnotify. > However unless i am overlooking something this is still likely to disrupt compatibility So, IIUC, the issue is that: a) older cron was directly using the fixed FILE__ENTRYPOINT definition from libselinux in a security_compute_av() call rather than dynamically looking up entrypoint permission, b) the value of the file entrypoint permission in policy has changed because you updated your policy and chose to place the watch* permissions in the common file definition to match the kernel. Note that you could have instead sprinkled copies of the watch* permissions across all of the individual file/dir/*_file classes and placed them at the end of the classes if you wanted to avoid this compatibility issue. The policy and kernel definitions no longer need to be identical; the kernel will dynamically map between them for its own permission checks. Also, this should have already been broken for you when map permission was added, which would have shown up as execute_no_trans being checked instead of entrypoint. This was already filed as a bug on cron in debian here: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 So, wrt compatibility, IIUC: - the kernel change does not break compatibility for old policy + old userspace, - new policy can choose to add the new permissions in a backward-compatible manner if desired, although refpolicy has already chosen not to do this for map permission, - the offending code in cron produces build warnings that were introduced in 2014 in libselinux to update their code to use the dynamic class/perm mapping support, which would resolve the issue. > >> >> Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> >> --- >> policy/Makefile | 4 ++ >> policy/test_notify.te | 74 ++++++++++++++++++++++++ >> tests/Makefile | 4 ++ >> tests/notify/Makefile | 5 ++ >> tests/notify/test | 101 +++++++++++++++++++++++++++++++++ >> tests/notify/test_fanotify.c | 105 +++++++++++++++++++++++++++++++++++ >> tests/notify/test_inotify.c | 43 ++++++++++++++ >> 7 files changed, 336 insertions(+) >> create mode 100644 policy/test_notify.te >> create mode 100644 tests/notify/Makefile >> create mode 100755 tests/notify/test >> create mode 100644 tests/notify/test_fanotify.c >> create mode 100644 tests/notify/test_inotify.c >> >> diff --git a/policy/Makefile b/policy/Makefile >> index 305b572..65f88c5 100644 >> --- a/policy/Makefile >> +++ b/policy/Makefile >> @@ -71,6 +71,10 @@ ifeq ($(shell grep -q corenet_sctp_bind_all_nodes $(POLDEV)/include/kernel/coren >> TARGETS += test_sctp.te >> endif >> >> +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) >> +TARGETS+=test_notify.te >> +endif >> + >> ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) >> TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te, $(TARGETS)) >> endif >> diff --git a/policy/test_notify.te b/policy/test_notify.te >> new file mode 100644 >> index 0000000..8ba6f1a >> --- /dev/null >> +++ b/policy/test_notify.te >> @@ -0,0 +1,74 @@ >> +#################################################### >> +# Policy for testing inoftify and fanotify watches # >> +#################################################### >> + >> +attribute test_notify_domain; >> + >> +# Type for the file on which we want to set a watch >> +type test_notify_file_t; >> +files_type(test_notify_file_t); >> + >> +# Domain for the process which CAN set a non-permission watch >> +type test_watch_t; >> +domain_type(test_watch_t); >> +unconfined_runs_test(test_watch_t); >> + >> +typeattribute test_watch_t test_notify_domain; >> +typeattribute test_watch_t testdomain; >> + >> +allow test_notify_domain self:capability sys_admin; >> + >> +allow test_watch_t test_notify_file_t:file { read write open watch }; >> + >> +# Domain for the process which CAN set a NON-access watch on a file >> +type test_perm_watch_t; >> +domain_type(test_perm_watch_t); >> +unconfined_runs_test(test_perm_watch_t); >> + >> +typeattribute test_perm_watch_t test_notify_domain; >> +typeattribute test_perm_watch_t testdomain; >> + >> +allow test_perm_watch_t test_notify_file_t:file { read write open watch watch_with_perm }; >> + >> +# Domain which CAN set a NON-perm watch which MAY read accesses >> +type test_read_watch_t; >> +domain_type(test_read_watch_t); >> +unconfined_runs_test(test_read_watch_t); >> + >> +typeattribute test_read_watch_t test_notify_domain; >> +typeattribute test_read_watch_t testdomain; >> + >> +allow test_read_watch_t test_notify_file_t:file { read write open watch watch_reads }; >> + >> +# Domain which CAN set any watch which CAN read accesses >> +type test_perm_read_watch_t; >> +domain_type(test_perm_read_watch_t); >> +unconfined_runs_test(test_perm_read_watch_t); >> + >> +typeattribute test_perm_read_watch_t test_notify_domain; >> +typeattribute test_perm_read_watch_t testdomain; >> + >> +allow test_perm_read_watch_t test_notify_file_t:file { read write open watch watch_with_perm watch_reads }; >> + >> +# Domain which CANNOT set any watches >> +type test_no_watch_t; >> +domain_type(test_no_watch_t); >> +unconfined_runs_test(test_no_watch_t); >> + >> +typeattribute test_no_watch_t test_notify_domain; >> +typeattribute test_no_watch_t testdomain; >> + >> +allow test_no_watch_t test_notify_file_t:file { read write open }; >> + >> +# Domain which has no write access but can watch >> +type test_rdonly_t; >> +domain_type(test_rdonly_t); >> +unconfined_runs_test(test_rdonly_t); >> + >> +typeattribute test_rdonly_t test_notify_domain; >> +typeattribute test_rdonly_t testdomain; >> + >> +allow test_rdonly_t test_notify_file_t:file { read open watch }; >> + >> +miscfiles_domain_entry_test_files(test_notify_domain); >> +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); >> diff --git a/tests/Makefile b/tests/Makefile >> index 63aa325..b99c96e 100644 >> --- a/tests/Makefile >> +++ b/tests/Makefile >> @@ -50,6 +50,10 @@ ifeq ($(shell grep "^SELINUX_INFINIBAND_PKEY_TEST=" infiniband_pkey/ibpkey_test. >> SUBDIRS += infiniband_pkey >> endif >> >> +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) >> +SUBDIRS+=notify >> +endif >> + >> ifeq ($(DISTRO),RHEL4) >> SUBDIRS:=$(filter-out bounds dyntrace dyntrans inet_socket mmap nnp_nosuid overlay unix_socket, $(SUBDIRS)) >> endif >> diff --git a/tests/notify/Makefile b/tests/notify/Makefile >> new file mode 100644 >> index 0000000..78c4b3b >> --- /dev/null >> +++ b/tests/notify/Makefile >> @@ -0,0 +1,5 @@ >> +TARGETS=test_inotify test_fanotify >> + >> +all: $(TARGETS) >> +clean: >> + rm -f $(TARGETS) >> diff --git a/tests/notify/test b/tests/notify/test >> new file mode 100755 >> index 0000000..21f03de >> --- /dev/null >> +++ b/tests/notify/test >> @@ -0,0 +1,101 @@ >> +#!/usr/bin/perl >> + >> +use Test; >> +BEGIN { plan tests => 14 } # number of tests to run >> + >> +# help the test script locate itself >> +$basedir = $0; >> +$basedir =~ s|(.*)/[^/]*|$1|; >> + >> +# Get rid of a testfile from last run if it's there (just in case) >> +system("rm -f $basedir/watch_me"); >> + >> +# Create a new test file >> +system("touch $basedir/watch_me"); >> +system("chcon -t test_notify_file_t $basedir/watch_me"); >> + >> +## TESTS >> + >> +## TEST BASIC WATCH PERMISSION >> +# Should be able to set inotify watch >> +$exit_val = >> + system("runcon -t test_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); >> +ok( $exit_val, 0 ); >> + >> +# Should be able to set non-permissions based fanotify watch >> +$exit_val = system( >> + "runcon -t test_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); >> +ok( $exit_val, 0 ); >> + >> +# Should NOT be able to set permission based fanotify watch >> +$exit_val = system( >> + "runcon -t test_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1"); >> +ok($exit_val); # this should fail >> + >> +# Should NOT be able to set read based fanotify watch >> +$exit_val = system( >> + "runcon -t test_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1"); >> +ok($exit_val); # this should fail >> + >> +# Should NOT be able to set read based inotify watch >> +$exit_val = system( >> + "runcon -t test_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1"); >> +ok($exit_val); # this should fail >> + >> +## TEST PERM WATCH >> +# Should be able to set permission based fanotify watch >> +$exit_val = system( >> +"runcon -t test_perm_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1" >> +); >> +ok( $exit_val, 0 ); >> + >> +# Should NOT be able to set watch of accesses >> +$exit_val = system( >> +"runcon -t test_perm_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1" >> +); >> +ok($exit_val); # this should fail >> + >> +## TEST READ NO PERM WATCH PERMSISSIONS >> +# Should NOT be able to set read and perm watch >> +$exit_val = system( >> +"runcon -t test_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" >> +); >> +ok($exit_val); # should fail >> + >> +# Should be able to set read inotify watch >> +$exit_val = system( >> +"runcon -t test_read_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1" >> +); >> +ok( $exit_val, 0 ); >> + >> +## TEST READ WITH PERM WATCH PERMSISSIONS >> +# Should be able to set read and perm watch >> +$exit_val = system( >> +"runcon -t test_perm_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" >> +); >> +ok( $exit_val, 0 ); >> + >> +## TEST NO WATCH PERMSISSIONS >> +# Should NOT be able to set inotify watch >> +$exit_val = system( >> + "runcon -t test_no_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); >> +ok($exit_val); # this should fail >> + >> +# Should NOT be able to set any fanotify watch >> +$exit_val = system( >> + "runcon -t test_no_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); >> +ok($exit_val); # this should fail >> + >> +## TEST READ ONLY >> +# Should NOT be able to get read-write descriptor >> +$exit_val = system( >> + "runcon -t test_rdonly_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); >> +ok($exit_val); # this should fail >> + >> +# Should be able to get read-write descriptor >> +$exit_val = system( >> + "runcon -t test_watch_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); >> +ok( $exit_val, 0 ); >> + >> +# Clean up test file >> +system("rm -f $basedir/watch_me"); >> diff --git a/tests/notify/test_fanotify.c b/tests/notify/test_fanotify.c >> new file mode 100644 >> index 0000000..fff773f >> --- /dev/null >> +++ b/tests/notify/test_fanotify.c >> @@ -0,0 +1,105 @@ >> +#define _GNU_SOURCE 1 >> + >> +#include <stdio.h> >> +#include <stdlib.h> >> + >> +#include <getopt.h> >> + >> +#include <fcntl.h> >> +#include <poll.h> >> +#include <sys/fanotify.h> >> +#include <unistd.h> >> + >> +void printUsage() >> +{ >> + fprintf(stderr, "Usage: test_fanotify [-p] [-r] [-l] file_name\n"); >> + exit(1); >> +} >> + >> +int main(int argc, char *argv[]) >> +{ >> + if (argc < 2) { >> + printUsage(); >> + } >> + >> + int fd, ret, arg; >> + int mask = FAN_OPEN; // default mask >> + int listening = 0; >> + >> + // the -p flag will test for watch_with_perm >> + // the mask used at mark will contain FAN_OPEN_PERM >> + // >> + // the -r flag will test for watching accesses to files for reads >> + // the mask will contain FAN_ACCESS >> + while ((arg = getopt(argc, argv, "prl")) != -1) { >> + switch (arg) { >> + case 'p': >> + mask |= FAN_OPEN_PERM; >> + break; >> + case 'r': >> + mask |= FAN_ACCESS; >> + break; >> + case 'l': >> + listening = 1; >> + break; >> + default: >> + printUsage(); >> + } >> + } >> + >> + // get file descriptor for new fanotify event queue >> + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); >> + if (fd < 0) { >> + perror("fanotify_init:bad file descriptor"); >> + exit(1); >> + } >> + >> + // mark a filesystem object and add mark to event queue >> + // get notifications on file opens, accesses, and closes >> + // use current working directory as base dir >> + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, AT_FDCWD, argv[optind]); >> + >> + if (ret < 0) { >> + perror("test_fanotify:watch denied"); >> + exit(1); >> + } >> + >> + // logic to actually listen for an event if the -l flag is passed >> + // this is used to test if an app with read-only access can get a read/write >> + // handle to the watched file >> + if (listening) { >> + if (fork() == 0) { // fork a child process to cause an event on the file >> + FILE *f; >> + >> + f = fopen(argv[optind], "r"); // open file for reading >> + fgetc(f); // read char from file >> + >> + fclose(f); >> + } else { // logic to watch for events and try to access file read/write >> + struct pollfd fds; >> + fds.fd = fd; >> + fds.events = POLLIN; >> + >> + while (listening) { >> + int polled = poll(&fds, 1, 1); >> + if (polled > 0) { >> + if (fds.revents & POLLIN) { >> + struct fanotify_event_metadata buff[200]; >> + >> + size_t len = read(fd, (void *)&buff, sizeof(buff)); >> + if (len == -1) { >> + perror("test_fanotify:can't open file"); >> + exit(1); >> + } else { >> + listening = 0; >> + break; >> + } >> + } >> + } else if (polled == -1) { >> + listening = 0; >> + } >> + } >> + } >> + } >> + exit(0); >> +} >> diff --git a/tests/notify/test_inotify.c b/tests/notify/test_inotify.c >> new file mode 100644 >> index 0000000..17c3565 >> --- /dev/null >> +++ b/tests/notify/test_inotify.c >> @@ -0,0 +1,43 @@ >> +#include <stdio.h> >> +#include <stdlib.h> >> +#include <sys/inotify.h> >> +#include <getopt.h> >> + >> +int main(int argc, char *argv[]) >> +{ >> + if (argc < 2) { >> + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); >> + exit(1); >> + } >> + >> + int fd, wd, arg; >> + int mask = IN_MODIFY; >> + >> + while ((arg = getopt(argc, argv, "pr")) != -1) { >> + switch (arg) { >> + case 'r': >> + mask |= IN_ACCESS; >> + break; >> + default: >> + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); >> + exit(1); >> + } >> + } >> + >> + // get new file descriptor for inotify access >> + fd = inotify_init(); >> + if (fd < 0) { >> + perror("inotify_init:bad file descriptor"); >> + exit(1); >> + } >> + >> + // set watch on file and get watch descriptor for accessing events on it >> + wd = inotify_add_watch(fd, argv[optind], mask); >> + >> + if (wd < 0) { >> + perror("test_inotify:watch denied"); >> + exit(1); >> + } >> + >> + exit(0); >> +} >> -- >> 2.21.0 >> >
On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: > On 9/10/19 1:59 AM, Dominick Grift wrote: > > On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: > > > Added a suite to test permissions for setting inotify and fanotify watches > > > on filesystem objects. Tests watch, watch_with_perm, and watch_reads permissions. > > > > Ive also "tested" the fsnotify patch. And my tests indicate that this might cause issues: > > > > I added the access vectors to my policy, but on older systems (debian 10) cron fails to start > > cron needs the "entrypoint" permission on /etc/crontab but it looks like appending the "watch" access vectors to common-file disrupted the ordering > > The result is that now i have to allow cron to "watch_read" /etc/crontab even though the neither kernel nor selinux user space are aware of the fsnotify access vectors > > It seems the cron selinux code got confused and now thinks watch_read is entrypoint (its using selinux code to determine whether it can manually transition to cronjob domains on crontabs) > > > > I am hoping this issue with resolve itself on systems with kernels and user spaces that suppose fsnotify. > > However unless i am overlooking something this is still likely to disrupt compatibility > > So, IIUC, the issue is that: > a) older cron was directly using the fixed FILE__ENTRYPOINT definition from > libselinux in a security_compute_av() call rather than dynamically looking > up entrypoint permission, > b) the value of the file entrypoint permission in policy has changed because > you updated your policy and chose to place the watch* permissions in the > common file definition to match the kernel. > > Note that you could have instead sprinkled copies of the watch* permissions > across all of the individual file/dir/*_file classes and placed them at the > end of the classes if you wanted to avoid this compatibility issue. The > policy and kernel definitions no longer need to be identical; the kernel > will dynamically map between them for its own permission checks. > > Also, this should have already been broken for you when map permission was > added, which would have shown up as execute_no_trans being checked instead > of entrypoint. This was already filed as a bug on cron in debian here: > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 > > So, wrt compatibility, IIUC: > - the kernel change does not break compatibility for old policy + old > userspace, > - new policy can choose to add the new permissions in a backward-compatible > manner if desired, although refpolicy has already chosen not to do this for > map permission, > - the offending code in cron produces build warnings that were introduced in > 2014 in libselinux to update their code to use the dynamic class/perm > mapping support, which would resolve the issue. this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x --common common_file Commons: 1 common common_file { append lock mounton unlink read create quotaon execute setattr map relabelto rename link ioctl getattr relabelfrom } [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile Classes: 1 class file inherits common_file { execmod watch write watch_reads execute_no_trans watch_mount watch_with_perm open watch_sb audit_access entrypoint } > > > > > > > > > Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> > > > --- > > > policy/Makefile | 4 ++ > > > policy/test_notify.te | 74 ++++++++++++++++++++++++ > > > tests/Makefile | 4 ++ > > > tests/notify/Makefile | 5 ++ > > > tests/notify/test | 101 +++++++++++++++++++++++++++++++++ > > > tests/notify/test_fanotify.c | 105 +++++++++++++++++++++++++++++++++++ > > > tests/notify/test_inotify.c | 43 ++++++++++++++ > > > 7 files changed, 336 insertions(+) > > > create mode 100644 policy/test_notify.te > > > create mode 100644 tests/notify/Makefile > > > create mode 100755 tests/notify/test > > > create mode 100644 tests/notify/test_fanotify.c > > > create mode 100644 tests/notify/test_inotify.c > > > > > > diff --git a/policy/Makefile b/policy/Makefile > > > index 305b572..65f88c5 100644 > > > --- a/policy/Makefile > > > +++ b/policy/Makefile > > > @@ -71,6 +71,10 @@ ifeq ($(shell grep -q corenet_sctp_bind_all_nodes $(POLDEV)/include/kernel/coren > > > TARGETS += test_sctp.te > > > endif > > > +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) > > > +TARGETS+=test_notify.te > > > +endif > > > + > > > ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) > > > TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te, $(TARGETS)) > > > endif > > > diff --git a/policy/test_notify.te b/policy/test_notify.te > > > new file mode 100644 > > > index 0000000..8ba6f1a > > > --- /dev/null > > > +++ b/policy/test_notify.te > > > @@ -0,0 +1,74 @@ > > > +#################################################### > > > +# Policy for testing inoftify and fanotify watches # > > > +#################################################### > > > + > > > +attribute test_notify_domain; > > > + > > > +# Type for the file on which we want to set a watch > > > +type test_notify_file_t; > > > +files_type(test_notify_file_t); > > > + > > > +# Domain for the process which CAN set a non-permission watch > > > +type test_watch_t; > > > +domain_type(test_watch_t); > > > +unconfined_runs_test(test_watch_t); > > > + > > > +typeattribute test_watch_t test_notify_domain; > > > +typeattribute test_watch_t testdomain; > > > + > > > +allow test_notify_domain self:capability sys_admin; > > > + > > > +allow test_watch_t test_notify_file_t:file { read write open watch }; > > > + > > > +# Domain for the process which CAN set a NON-access watch on a file > > > +type test_perm_watch_t; > > > +domain_type(test_perm_watch_t); > > > +unconfined_runs_test(test_perm_watch_t); > > > + > > > +typeattribute test_perm_watch_t test_notify_domain; > > > +typeattribute test_perm_watch_t testdomain; > > > + > > > +allow test_perm_watch_t test_notify_file_t:file { read write open watch watch_with_perm }; > > > + > > > +# Domain which CAN set a NON-perm watch which MAY read accesses > > > +type test_read_watch_t; > > > +domain_type(test_read_watch_t); > > > +unconfined_runs_test(test_read_watch_t); > > > + > > > +typeattribute test_read_watch_t test_notify_domain; > > > +typeattribute test_read_watch_t testdomain; > > > + > > > +allow test_read_watch_t test_notify_file_t:file { read write open watch watch_reads }; > > > + > > > +# Domain which CAN set any watch which CAN read accesses > > > +type test_perm_read_watch_t; > > > +domain_type(test_perm_read_watch_t); > > > +unconfined_runs_test(test_perm_read_watch_t); > > > + > > > +typeattribute test_perm_read_watch_t test_notify_domain; > > > +typeattribute test_perm_read_watch_t testdomain; > > > + > > > +allow test_perm_read_watch_t test_notify_file_t:file { read write open watch watch_with_perm watch_reads }; > > > + > > > +# Domain which CANNOT set any watches > > > +type test_no_watch_t; > > > +domain_type(test_no_watch_t); > > > +unconfined_runs_test(test_no_watch_t); > > > + > > > +typeattribute test_no_watch_t test_notify_domain; > > > +typeattribute test_no_watch_t testdomain; > > > + > > > +allow test_no_watch_t test_notify_file_t:file { read write open }; > > > + > > > +# Domain which has no write access but can watch > > > +type test_rdonly_t; > > > +domain_type(test_rdonly_t); > > > +unconfined_runs_test(test_rdonly_t); > > > + > > > +typeattribute test_rdonly_t test_notify_domain; > > > +typeattribute test_rdonly_t testdomain; > > > + > > > +allow test_rdonly_t test_notify_file_t:file { read open watch }; > > > + > > > +miscfiles_domain_entry_test_files(test_notify_domain); > > > +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); > > > diff --git a/tests/Makefile b/tests/Makefile > > > index 63aa325..b99c96e 100644 > > > --- a/tests/Makefile > > > +++ b/tests/Makefile > > > @@ -50,6 +50,10 @@ ifeq ($(shell grep "^SELINUX_INFINIBAND_PKEY_TEST=" infiniband_pkey/ibpkey_test. > > > SUBDIRS += infiniband_pkey > > > endif > > > +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) > > > +SUBDIRS+=notify > > > +endif > > > + > > > ifeq ($(DISTRO),RHEL4) > > > SUBDIRS:=$(filter-out bounds dyntrace dyntrans inet_socket mmap nnp_nosuid overlay unix_socket, $(SUBDIRS)) > > > endif > > > diff --git a/tests/notify/Makefile b/tests/notify/Makefile > > > new file mode 100644 > > > index 0000000..78c4b3b > > > --- /dev/null > > > +++ b/tests/notify/Makefile > > > @@ -0,0 +1,5 @@ > > > +TARGETS=test_inotify test_fanotify > > > + > > > +all: $(TARGETS) > > > +clean: > > > + rm -f $(TARGETS) > > > diff --git a/tests/notify/test b/tests/notify/test > > > new file mode 100755 > > > index 0000000..21f03de > > > --- /dev/null > > > +++ b/tests/notify/test > > > @@ -0,0 +1,101 @@ > > > +#!/usr/bin/perl > > > + > > > +use Test; > > > +BEGIN { plan tests => 14 } # number of tests to run > > > + > > > +# help the test script locate itself > > > +$basedir = $0; > > > +$basedir =~ s|(.*)/[^/]*|$1|; > > > + > > > +# Get rid of a testfile from last run if it's there (just in case) > > > +system("rm -f $basedir/watch_me"); > > > + > > > +# Create a new test file > > > +system("touch $basedir/watch_me"); > > > +system("chcon -t test_notify_file_t $basedir/watch_me"); > > > + > > > +## TESTS > > > + > > > +## TEST BASIC WATCH PERMISSION > > > +# Should be able to set inotify watch > > > +$exit_val = > > > + system("runcon -t test_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); > > > +ok( $exit_val, 0 ); > > > + > > > +# Should be able to set non-permissions based fanotify watch > > > +$exit_val = system( > > > + "runcon -t test_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); > > > +ok( $exit_val, 0 ); > > > + > > > +# Should NOT be able to set permission based fanotify watch > > > +$exit_val = system( > > > + "runcon -t test_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1"); > > > +ok($exit_val); # this should fail > > > + > > > +# Should NOT be able to set read based fanotify watch > > > +$exit_val = system( > > > + "runcon -t test_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1"); > > > +ok($exit_val); # this should fail > > > + > > > +# Should NOT be able to set read based inotify watch > > > +$exit_val = system( > > > + "runcon -t test_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1"); > > > +ok($exit_val); # this should fail > > > + > > > +## TEST PERM WATCH > > > +# Should be able to set permission based fanotify watch > > > +$exit_val = system( > > > +"runcon -t test_perm_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1" > > > +); > > > +ok( $exit_val, 0 ); > > > + > > > +# Should NOT be able to set watch of accesses > > > +$exit_val = system( > > > +"runcon -t test_perm_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1" > > > +); > > > +ok($exit_val); # this should fail > > > + > > > +## TEST READ NO PERM WATCH PERMSISSIONS > > > +# Should NOT be able to set read and perm watch > > > +$exit_val = system( > > > +"runcon -t test_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" > > > +); > > > +ok($exit_val); # should fail > > > + > > > +# Should be able to set read inotify watch > > > +$exit_val = system( > > > +"runcon -t test_read_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1" > > > +); > > > +ok( $exit_val, 0 ); > > > + > > > +## TEST READ WITH PERM WATCH PERMSISSIONS > > > +# Should be able to set read and perm watch > > > +$exit_val = system( > > > +"runcon -t test_perm_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" > > > +); > > > +ok( $exit_val, 0 ); > > > + > > > +## TEST NO WATCH PERMSISSIONS > > > +# Should NOT be able to set inotify watch > > > +$exit_val = system( > > > + "runcon -t test_no_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); > > > +ok($exit_val); # this should fail > > > + > > > +# Should NOT be able to set any fanotify watch > > > +$exit_val = system( > > > + "runcon -t test_no_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); > > > +ok($exit_val); # this should fail > > > + > > > +## TEST READ ONLY > > > +# Should NOT be able to get read-write descriptor > > > +$exit_val = system( > > > + "runcon -t test_rdonly_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); > > > +ok($exit_val); # this should fail > > > + > > > +# Should be able to get read-write descriptor > > > +$exit_val = system( > > > + "runcon -t test_watch_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); > > > +ok( $exit_val, 0 ); > > > + > > > +# Clean up test file > > > +system("rm -f $basedir/watch_me"); > > > diff --git a/tests/notify/test_fanotify.c b/tests/notify/test_fanotify.c > > > new file mode 100644 > > > index 0000000..fff773f > > > --- /dev/null > > > +++ b/tests/notify/test_fanotify.c > > > @@ -0,0 +1,105 @@ > > > +#define _GNU_SOURCE 1 > > > + > > > +#include <stdio.h> > > > +#include <stdlib.h> > > > + > > > +#include <getopt.h> > > > + > > > +#include <fcntl.h> > > > +#include <poll.h> > > > +#include <sys/fanotify.h> > > > +#include <unistd.h> > > > + > > > +void printUsage() > > > +{ > > > + fprintf(stderr, "Usage: test_fanotify [-p] [-r] [-l] file_name\n"); > > > + exit(1); > > > +} > > > + > > > +int main(int argc, char *argv[]) > > > +{ > > > + if (argc < 2) { > > > + printUsage(); > > > + } > > > + > > > + int fd, ret, arg; > > > + int mask = FAN_OPEN; // default mask > > > + int listening = 0; > > > + > > > + // the -p flag will test for watch_with_perm > > > + // the mask used at mark will contain FAN_OPEN_PERM > > > + // > > > + // the -r flag will test for watching accesses to files for reads > > > + // the mask will contain FAN_ACCESS > > > + while ((arg = getopt(argc, argv, "prl")) != -1) { > > > + switch (arg) { > > > + case 'p': > > > + mask |= FAN_OPEN_PERM; > > > + break; > > > + case 'r': > > > + mask |= FAN_ACCESS; > > > + break; > > > + case 'l': > > > + listening = 1; > > > + break; > > > + default: > > > + printUsage(); > > > + } > > > + } > > > + > > > + // get file descriptor for new fanotify event queue > > > + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); > > > + if (fd < 0) { > > > + perror("fanotify_init:bad file descriptor"); > > > + exit(1); > > > + } > > > + > > > + // mark a filesystem object and add mark to event queue > > > + // get notifications on file opens, accesses, and closes > > > + // use current working directory as base dir > > > + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, AT_FDCWD, argv[optind]); > > > + > > > + if (ret < 0) { > > > + perror("test_fanotify:watch denied"); > > > + exit(1); > > > + } > > > + > > > + // logic to actually listen for an event if the -l flag is passed > > > + // this is used to test if an app with read-only access can get a read/write > > > + // handle to the watched file > > > + if (listening) { > > > + if (fork() == 0) { // fork a child process to cause an event on the file > > > + FILE *f; > > > + > > > + f = fopen(argv[optind], "r"); // open file for reading > > > + fgetc(f); // read char from file > > > + > > > + fclose(f); > > > + } else { // logic to watch for events and try to access file read/write > > > + struct pollfd fds; > > > + fds.fd = fd; > > > + fds.events = POLLIN; > > > + > > > + while (listening) { > > > + int polled = poll(&fds, 1, 1); > > > + if (polled > 0) { > > > + if (fds.revents & POLLIN) { > > > + struct fanotify_event_metadata buff[200]; > > > + > > > + size_t len = read(fd, (void *)&buff, sizeof(buff)); > > > + if (len == -1) { > > > + perror("test_fanotify:can't open file"); > > > + exit(1); > > > + } else { > > > + listening = 0; > > > + break; > > > + } > > > + } > > > + } else if (polled == -1) { > > > + listening = 0; > > > + } > > > + } > > > + } > > > + } > > > + exit(0); > > > +} > > > diff --git a/tests/notify/test_inotify.c b/tests/notify/test_inotify.c > > > new file mode 100644 > > > index 0000000..17c3565 > > > --- /dev/null > > > +++ b/tests/notify/test_inotify.c > > > @@ -0,0 +1,43 @@ > > > +#include <stdio.h> > > > +#include <stdlib.h> > > > +#include <sys/inotify.h> > > > +#include <getopt.h> > > > + > > > +int main(int argc, char *argv[]) > > > +{ > > > + if (argc < 2) { > > > + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); > > > + exit(1); > > > + } > > > + > > > + int fd, wd, arg; > > > + int mask = IN_MODIFY; > > > + > > > + while ((arg = getopt(argc, argv, "pr")) != -1) { > > > + switch (arg) { > > > + case 'r': > > > + mask |= IN_ACCESS; > > > + break; > > > + default: > > > + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); > > > + exit(1); > > > + } > > > + } > > > + > > > + // get new file descriptor for inotify access > > > + fd = inotify_init(); > > > + if (fd < 0) { > > > + perror("inotify_init:bad file descriptor"); > > > + exit(1); > > > + } > > > + > > > + // set watch on file and get watch descriptor for accessing events on it > > > + wd = inotify_add_watch(fd, argv[optind], mask); > > > + > > > + if (wd < 0) { > > > + perror("test_inotify:watch denied"); > > > + exit(1); > > > + } > > > + > > > + exit(0); > > > +} > > > -- > > > 2.21.0 > > > > > >
On Tue, Sep 10, 2019 at 04:15:18PM +0200, Dominick Grift wrote: > On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: > > On 9/10/19 1:59 AM, Dominick Grift wrote: > > > On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: > > > > Added a suite to test permissions for setting inotify and fanotify watches > > > > on filesystem objects. Tests watch, watch_with_perm, and watch_reads permissions. > > > > > > Ive also "tested" the fsnotify patch. And my tests indicate that this might cause issues: > > > > > > I added the access vectors to my policy, but on older systems (debian 10) cron fails to start > > > cron needs the "entrypoint" permission on /etc/crontab but it looks like appending the "watch" access vectors to common-file disrupted the ordering > > > The result is that now i have to allow cron to "watch_read" /etc/crontab even though the neither kernel nor selinux user space are aware of the fsnotify access vectors > > > It seems the cron selinux code got confused and now thinks watch_read is entrypoint (its using selinux code to determine whether it can manually transition to cronjob domains on crontabs) > > > > > > I am hoping this issue with resolve itself on systems with kernels and user spaces that suppose fsnotify. > > > However unless i am overlooking something this is still likely to disrupt compatibility > > > > So, IIUC, the issue is that: > > a) older cron was directly using the fixed FILE__ENTRYPOINT definition from > > libselinux in a security_compute_av() call rather than dynamically looking > > up entrypoint permission, > > b) the value of the file entrypoint permission in policy has changed because > > you updated your policy and chose to place the watch* permissions in the > > common file definition to match the kernel. > > > > Note that you could have instead sprinkled copies of the watch* permissions > > across all of the individual file/dir/*_file classes and placed them at the > > end of the classes if you wanted to avoid this compatibility issue. The > > policy and kernel definitions no longer need to be identical; the kernel > > will dynamically map between them for its own permission checks. > > > > Also, this should have already been broken for you when map permission was > > added, which would have shown up as execute_no_trans being checked instead > > of entrypoint. This was already filed as a bug on cron in debian here: > > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 > > > > So, wrt compatibility, IIUC: > > - the kernel change does not break compatibility for old policy + old > > userspace, > > - new policy can choose to add the new permissions in a backward-compatible > > manner if desired, although refpolicy has already chosen not to do this for > > map permission, > > - the offending code in cron produces build warnings that were introduced in > > 2014 in libselinux to update their code to use the dynamic class/perm > > mapping support, which would resolve the issue. > > this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d Sorry i overlooked the last two paragraphs, ill try moving map from common_file as well > > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x --common common_file > > Commons: 1 > common common_file > { > append > lock > mounton > unlink > read > create > quotaon > execute > setattr > map > relabelto > rename > link > ioctl > getattr > relabelfrom > } > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile > > Classes: 1 > class file > inherits common_file > { > execmod > watch > write > watch_reads > execute_no_trans > watch_mount > watch_with_perm > open > watch_sb > audit_access > entrypoint > } > > > > > > > > > > > > > > > Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> > > > > --- > > > > policy/Makefile | 4 ++ > > > > policy/test_notify.te | 74 ++++++++++++++++++++++++ > > > > tests/Makefile | 4 ++ > > > > tests/notify/Makefile | 5 ++ > > > > tests/notify/test | 101 +++++++++++++++++++++++++++++++++ > > > > tests/notify/test_fanotify.c | 105 +++++++++++++++++++++++++++++++++++ > > > > tests/notify/test_inotify.c | 43 ++++++++++++++ > > > > 7 files changed, 336 insertions(+) > > > > create mode 100644 policy/test_notify.te > > > > create mode 100644 tests/notify/Makefile > > > > create mode 100755 tests/notify/test > > > > create mode 100644 tests/notify/test_fanotify.c > > > > create mode 100644 tests/notify/test_inotify.c > > > > > > > > diff --git a/policy/Makefile b/policy/Makefile > > > > index 305b572..65f88c5 100644 > > > > --- a/policy/Makefile > > > > +++ b/policy/Makefile > > > > @@ -71,6 +71,10 @@ ifeq ($(shell grep -q corenet_sctp_bind_all_nodes $(POLDEV)/include/kernel/coren > > > > TARGETS += test_sctp.te > > > > endif > > > > +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) > > > > +TARGETS+=test_notify.te > > > > +endif > > > > + > > > > ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) > > > > TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te, $(TARGETS)) > > > > endif > > > > diff --git a/policy/test_notify.te b/policy/test_notify.te > > > > new file mode 100644 > > > > index 0000000..8ba6f1a > > > > --- /dev/null > > > > +++ b/policy/test_notify.te > > > > @@ -0,0 +1,74 @@ > > > > +#################################################### > > > > +# Policy for testing inoftify and fanotify watches # > > > > +#################################################### > > > > + > > > > +attribute test_notify_domain; > > > > + > > > > +# Type for the file on which we want to set a watch > > > > +type test_notify_file_t; > > > > +files_type(test_notify_file_t); > > > > + > > > > +# Domain for the process which CAN set a non-permission watch > > > > +type test_watch_t; > > > > +domain_type(test_watch_t); > > > > +unconfined_runs_test(test_watch_t); > > > > + > > > > +typeattribute test_watch_t test_notify_domain; > > > > +typeattribute test_watch_t testdomain; > > > > + > > > > +allow test_notify_domain self:capability sys_admin; > > > > + > > > > +allow test_watch_t test_notify_file_t:file { read write open watch }; > > > > + > > > > +# Domain for the process which CAN set a NON-access watch on a file > > > > +type test_perm_watch_t; > > > > +domain_type(test_perm_watch_t); > > > > +unconfined_runs_test(test_perm_watch_t); > > > > + > > > > +typeattribute test_perm_watch_t test_notify_domain; > > > > +typeattribute test_perm_watch_t testdomain; > > > > + > > > > +allow test_perm_watch_t test_notify_file_t:file { read write open watch watch_with_perm }; > > > > + > > > > +# Domain which CAN set a NON-perm watch which MAY read accesses > > > > +type test_read_watch_t; > > > > +domain_type(test_read_watch_t); > > > > +unconfined_runs_test(test_read_watch_t); > > > > + > > > > +typeattribute test_read_watch_t test_notify_domain; > > > > +typeattribute test_read_watch_t testdomain; > > > > + > > > > +allow test_read_watch_t test_notify_file_t:file { read write open watch watch_reads }; > > > > + > > > > +# Domain which CAN set any watch which CAN read accesses > > > > +type test_perm_read_watch_t; > > > > +domain_type(test_perm_read_watch_t); > > > > +unconfined_runs_test(test_perm_read_watch_t); > > > > + > > > > +typeattribute test_perm_read_watch_t test_notify_domain; > > > > +typeattribute test_perm_read_watch_t testdomain; > > > > + > > > > +allow test_perm_read_watch_t test_notify_file_t:file { read write open watch watch_with_perm watch_reads }; > > > > + > > > > +# Domain which CANNOT set any watches > > > > +type test_no_watch_t; > > > > +domain_type(test_no_watch_t); > > > > +unconfined_runs_test(test_no_watch_t); > > > > + > > > > +typeattribute test_no_watch_t test_notify_domain; > > > > +typeattribute test_no_watch_t testdomain; > > > > + > > > > +allow test_no_watch_t test_notify_file_t:file { read write open }; > > > > + > > > > +# Domain which has no write access but can watch > > > > +type test_rdonly_t; > > > > +domain_type(test_rdonly_t); > > > > +unconfined_runs_test(test_rdonly_t); > > > > + > > > > +typeattribute test_rdonly_t test_notify_domain; > > > > +typeattribute test_rdonly_t testdomain; > > > > + > > > > +allow test_rdonly_t test_notify_file_t:file { read open watch }; > > > > + > > > > +miscfiles_domain_entry_test_files(test_notify_domain); > > > > +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); > > > > diff --git a/tests/Makefile b/tests/Makefile > > > > index 63aa325..b99c96e 100644 > > > > --- a/tests/Makefile > > > > +++ b/tests/Makefile > > > > @@ -50,6 +50,10 @@ ifeq ($(shell grep "^SELINUX_INFINIBAND_PKEY_TEST=" infiniband_pkey/ibpkey_test. > > > > SUBDIRS += infiniband_pkey > > > > endif > > > > +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) > > > > +SUBDIRS+=notify > > > > +endif > > > > + > > > > ifeq ($(DISTRO),RHEL4) > > > > SUBDIRS:=$(filter-out bounds dyntrace dyntrans inet_socket mmap nnp_nosuid overlay unix_socket, $(SUBDIRS)) > > > > endif > > > > diff --git a/tests/notify/Makefile b/tests/notify/Makefile > > > > new file mode 100644 > > > > index 0000000..78c4b3b > > > > --- /dev/null > > > > +++ b/tests/notify/Makefile > > > > @@ -0,0 +1,5 @@ > > > > +TARGETS=test_inotify test_fanotify > > > > + > > > > +all: $(TARGETS) > > > > +clean: > > > > + rm -f $(TARGETS) > > > > diff --git a/tests/notify/test b/tests/notify/test > > > > new file mode 100755 > > > > index 0000000..21f03de > > > > --- /dev/null > > > > +++ b/tests/notify/test > > > > @@ -0,0 +1,101 @@ > > > > +#!/usr/bin/perl > > > > + > > > > +use Test; > > > > +BEGIN { plan tests => 14 } # number of tests to run > > > > + > > > > +# help the test script locate itself > > > > +$basedir = $0; > > > > +$basedir =~ s|(.*)/[^/]*|$1|; > > > > + > > > > +# Get rid of a testfile from last run if it's there (just in case) > > > > +system("rm -f $basedir/watch_me"); > > > > + > > > > +# Create a new test file > > > > +system("touch $basedir/watch_me"); > > > > +system("chcon -t test_notify_file_t $basedir/watch_me"); > > > > + > > > > +## TESTS > > > > + > > > > +## TEST BASIC WATCH PERMISSION > > > > +# Should be able to set inotify watch > > > > +$exit_val = > > > > + system("runcon -t test_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); > > > > +ok( $exit_val, 0 ); > > > > + > > > > +# Should be able to set non-permissions based fanotify watch > > > > +$exit_val = system( > > > > + "runcon -t test_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); > > > > +ok( $exit_val, 0 ); > > > > + > > > > +# Should NOT be able to set permission based fanotify watch > > > > +$exit_val = system( > > > > + "runcon -t test_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1"); > > > > +ok($exit_val); # this should fail > > > > + > > > > +# Should NOT be able to set read based fanotify watch > > > > +$exit_val = system( > > > > + "runcon -t test_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1"); > > > > +ok($exit_val); # this should fail > > > > + > > > > +# Should NOT be able to set read based inotify watch > > > > +$exit_val = system( > > > > + "runcon -t test_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1"); > > > > +ok($exit_val); # this should fail > > > > + > > > > +## TEST PERM WATCH > > > > +# Should be able to set permission based fanotify watch > > > > +$exit_val = system( > > > > +"runcon -t test_perm_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1" > > > > +); > > > > +ok( $exit_val, 0 ); > > > > + > > > > +# Should NOT be able to set watch of accesses > > > > +$exit_val = system( > > > > +"runcon -t test_perm_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1" > > > > +); > > > > +ok($exit_val); # this should fail > > > > + > > > > +## TEST READ NO PERM WATCH PERMSISSIONS > > > > +# Should NOT be able to set read and perm watch > > > > +$exit_val = system( > > > > +"runcon -t test_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" > > > > +); > > > > +ok($exit_val); # should fail > > > > + > > > > +# Should be able to set read inotify watch > > > > +$exit_val = system( > > > > +"runcon -t test_read_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1" > > > > +); > > > > +ok( $exit_val, 0 ); > > > > + > > > > +## TEST READ WITH PERM WATCH PERMSISSIONS > > > > +# Should be able to set read and perm watch > > > > +$exit_val = system( > > > > +"runcon -t test_perm_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" > > > > +); > > > > +ok( $exit_val, 0 ); > > > > + > > > > +## TEST NO WATCH PERMSISSIONS > > > > +# Should NOT be able to set inotify watch > > > > +$exit_val = system( > > > > + "runcon -t test_no_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); > > > > +ok($exit_val); # this should fail > > > > + > > > > +# Should NOT be able to set any fanotify watch > > > > +$exit_val = system( > > > > + "runcon -t test_no_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); > > > > +ok($exit_val); # this should fail > > > > + > > > > +## TEST READ ONLY > > > > +# Should NOT be able to get read-write descriptor > > > > +$exit_val = system( > > > > + "runcon -t test_rdonly_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); > > > > +ok($exit_val); # this should fail > > > > + > > > > +# Should be able to get read-write descriptor > > > > +$exit_val = system( > > > > + "runcon -t test_watch_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); > > > > +ok( $exit_val, 0 ); > > > > + > > > > +# Clean up test file > > > > +system("rm -f $basedir/watch_me"); > > > > diff --git a/tests/notify/test_fanotify.c b/tests/notify/test_fanotify.c > > > > new file mode 100644 > > > > index 0000000..fff773f > > > > --- /dev/null > > > > +++ b/tests/notify/test_fanotify.c > > > > @@ -0,0 +1,105 @@ > > > > +#define _GNU_SOURCE 1 > > > > + > > > > +#include <stdio.h> > > > > +#include <stdlib.h> > > > > + > > > > +#include <getopt.h> > > > > + > > > > +#include <fcntl.h> > > > > +#include <poll.h> > > > > +#include <sys/fanotify.h> > > > > +#include <unistd.h> > > > > + > > > > +void printUsage() > > > > +{ > > > > + fprintf(stderr, "Usage: test_fanotify [-p] [-r] [-l] file_name\n"); > > > > + exit(1); > > > > +} > > > > + > > > > +int main(int argc, char *argv[]) > > > > +{ > > > > + if (argc < 2) { > > > > + printUsage(); > > > > + } > > > > + > > > > + int fd, ret, arg; > > > > + int mask = FAN_OPEN; // default mask > > > > + int listening = 0; > > > > + > > > > + // the -p flag will test for watch_with_perm > > > > + // the mask used at mark will contain FAN_OPEN_PERM > > > > + // > > > > + // the -r flag will test for watching accesses to files for reads > > > > + // the mask will contain FAN_ACCESS > > > > + while ((arg = getopt(argc, argv, "prl")) != -1) { > > > > + switch (arg) { > > > > + case 'p': > > > > + mask |= FAN_OPEN_PERM; > > > > + break; > > > > + case 'r': > > > > + mask |= FAN_ACCESS; > > > > + break; > > > > + case 'l': > > > > + listening = 1; > > > > + break; > > > > + default: > > > > + printUsage(); > > > > + } > > > > + } > > > > + > > > > + // get file descriptor for new fanotify event queue > > > > + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); > > > > + if (fd < 0) { > > > > + perror("fanotify_init:bad file descriptor"); > > > > + exit(1); > > > > + } > > > > + > > > > + // mark a filesystem object and add mark to event queue > > > > + // get notifications on file opens, accesses, and closes > > > > + // use current working directory as base dir > > > > + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, AT_FDCWD, argv[optind]); > > > > + > > > > + if (ret < 0) { > > > > + perror("test_fanotify:watch denied"); > > > > + exit(1); > > > > + } > > > > + > > > > + // logic to actually listen for an event if the -l flag is passed > > > > + // this is used to test if an app with read-only access can get a read/write > > > > + // handle to the watched file > > > > + if (listening) { > > > > + if (fork() == 0) { // fork a child process to cause an event on the file > > > > + FILE *f; > > > > + > > > > + f = fopen(argv[optind], "r"); // open file for reading > > > > + fgetc(f); // read char from file > > > > + > > > > + fclose(f); > > > > + } else { // logic to watch for events and try to access file read/write > > > > + struct pollfd fds; > > > > + fds.fd = fd; > > > > + fds.events = POLLIN; > > > > + > > > > + while (listening) { > > > > + int polled = poll(&fds, 1, 1); > > > > + if (polled > 0) { > > > > + if (fds.revents & POLLIN) { > > > > + struct fanotify_event_metadata buff[200]; > > > > + > > > > + size_t len = read(fd, (void *)&buff, sizeof(buff)); > > > > + if (len == -1) { > > > > + perror("test_fanotify:can't open file"); > > > > + exit(1); > > > > + } else { > > > > + listening = 0; > > > > + break; > > > > + } > > > > + } > > > > + } else if (polled == -1) { > > > > + listening = 0; > > > > + } > > > > + } > > > > + } > > > > + } > > > > + exit(0); > > > > +} > > > > diff --git a/tests/notify/test_inotify.c b/tests/notify/test_inotify.c > > > > new file mode 100644 > > > > index 0000000..17c3565 > > > > --- /dev/null > > > > +++ b/tests/notify/test_inotify.c > > > > @@ -0,0 +1,43 @@ > > > > +#include <stdio.h> > > > > +#include <stdlib.h> > > > > +#include <sys/inotify.h> > > > > +#include <getopt.h> > > > > + > > > > +int main(int argc, char *argv[]) > > > > +{ > > > > + if (argc < 2) { > > > > + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); > > > > + exit(1); > > > > + } > > > > + > > > > + int fd, wd, arg; > > > > + int mask = IN_MODIFY; > > > > + > > > > + while ((arg = getopt(argc, argv, "pr")) != -1) { > > > > + switch (arg) { > > > > + case 'r': > > > > + mask |= IN_ACCESS; > > > > + break; > > > > + default: > > > > + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); > > > > + exit(1); > > > > + } > > > > + } > > > > + > > > > + // get new file descriptor for inotify access > > > > + fd = inotify_init(); > > > > + if (fd < 0) { > > > > + perror("inotify_init:bad file descriptor"); > > > > + exit(1); > > > > + } > > > > + > > > > + // set watch on file and get watch descriptor for accessing events on it > > > > + wd = inotify_add_watch(fd, argv[optind], mask); > > > > + > > > > + if (wd < 0) { > > > > + perror("test_inotify:watch denied"); > > > > + exit(1); > > > > + } > > > > + > > > > + exit(0); > > > > +} > > > > -- > > > > 2.21.0 > > > > > > > > > > > -- > Key fingerprint = 5F4D 3CDB D3F8 3652 FBD8 02D5 3B6C 5F1D 2C7B 6B02 > https://sks-keyservers.net/pks/lookup?op=get&search=0x3B6C5F1D2C7B6B02 > Dominick Grift
On 9/10/19 10:15 AM, Dominick Grift wrote: > On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: >> On 9/10/19 1:59 AM, Dominick Grift wrote: >>> On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: >>>> Added a suite to test permissions for setting inotify and fanotify watches >>>> on filesystem objects. Tests watch, watch_with_perm, and watch_reads permissions. >>> >>> Ive also "tested" the fsnotify patch. And my tests indicate that this might cause issues: >>> >>> I added the access vectors to my policy, but on older systems (debian 10) cron fails to start >>> cron needs the "entrypoint" permission on /etc/crontab but it looks like appending the "watch" access vectors to common-file disrupted the ordering >>> The result is that now i have to allow cron to "watch_read" /etc/crontab even though the neither kernel nor selinux user space are aware of the fsnotify access vectors >>> It seems the cron selinux code got confused and now thinks watch_read is entrypoint (its using selinux code to determine whether it can manually transition to cronjob domains on crontabs) >>> >>> I am hoping this issue with resolve itself on systems with kernels and user spaces that suppose fsnotify. >>> However unless i am overlooking something this is still likely to disrupt compatibility >> >> So, IIUC, the issue is that: >> a) older cron was directly using the fixed FILE__ENTRYPOINT definition from >> libselinux in a security_compute_av() call rather than dynamically looking >> up entrypoint permission, >> b) the value of the file entrypoint permission in policy has changed because >> you updated your policy and chose to place the watch* permissions in the >> common file definition to match the kernel. >> >> Note that you could have instead sprinkled copies of the watch* permissions >> across all of the individual file/dir/*_file classes and placed them at the >> end of the classes if you wanted to avoid this compatibility issue. The >> policy and kernel definitions no longer need to be identical; the kernel >> will dynamically map between them for its own permission checks. >> >> Also, this should have already been broken for you when map permission was >> added, which would have shown up as execute_no_trans being checked instead >> of entrypoint. This was already filed as a bug on cron in debian here: >> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 >> >> So, wrt compatibility, IIUC: >> - the kernel change does not break compatibility for old policy + old >> userspace, >> - new policy can choose to add the new permissions in a backward-compatible >> manner if desired, although refpolicy has already chosen not to do this for >> map permission, >> - the offending code in cron produces build warnings that were introduced in >> 2014 in libselinux to update their code to use the dynamic class/perm >> mapping support, which would resolve the issue. > > this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d > > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x --common common_file > > Commons: 1 > common common_file > { > append > lock > mounton > unlink > read > create > quotaon > execute > setattr > map > relabelto > rename > link > ioctl > getattr > relabelfrom > } > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile > > Classes: 1 > class file > inherits common_file > { > execmod > watch > write > watch_reads > execute_no_trans > watch_mount > watch_with_perm > open > watch_sb > audit_access > entrypoint > } If you want to preserve compatibility with userspace using fixed definitions of FILE__ENTRYPOINT, then you have to insert any new file permissions after the current entrypoint permission in the class file. So watch and friends have to go after it, not before it. Also, since the kernel always uses FILE__WATCH* in the check code rather than distinguishing by class, the watch* permissions need to be at the same offset in all of the file classes. The same is true of the other file permissions. It looks like you may have other permissions out of sync across the file classes e.g. execmod, open, audit_access, that need to be aligned or the kernel could check the wrong permission. > >> >>> >>>> >>>> Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> >>>> --- >>>> policy/Makefile | 4 ++ >>>> policy/test_notify.te | 74 ++++++++++++++++++++++++ >>>> tests/Makefile | 4 ++ >>>> tests/notify/Makefile | 5 ++ >>>> tests/notify/test | 101 +++++++++++++++++++++++++++++++++ >>>> tests/notify/test_fanotify.c | 105 +++++++++++++++++++++++++++++++++++ >>>> tests/notify/test_inotify.c | 43 ++++++++++++++ >>>> 7 files changed, 336 insertions(+) >>>> create mode 100644 policy/test_notify.te >>>> create mode 100644 tests/notify/Makefile >>>> create mode 100755 tests/notify/test >>>> create mode 100644 tests/notify/test_fanotify.c >>>> create mode 100644 tests/notify/test_inotify.c >>>> >>>> diff --git a/policy/Makefile b/policy/Makefile >>>> index 305b572..65f88c5 100644 >>>> --- a/policy/Makefile >>>> +++ b/policy/Makefile >>>> @@ -71,6 +71,10 @@ ifeq ($(shell grep -q corenet_sctp_bind_all_nodes $(POLDEV)/include/kernel/coren >>>> TARGETS += test_sctp.te >>>> endif >>>> +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) >>>> +TARGETS+=test_notify.te >>>> +endif >>>> + >>>> ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) >>>> TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te, $(TARGETS)) >>>> endif >>>> diff --git a/policy/test_notify.te b/policy/test_notify.te >>>> new file mode 100644 >>>> index 0000000..8ba6f1a >>>> --- /dev/null >>>> +++ b/policy/test_notify.te >>>> @@ -0,0 +1,74 @@ >>>> +#################################################### >>>> +# Policy for testing inoftify and fanotify watches # >>>> +#################################################### >>>> + >>>> +attribute test_notify_domain; >>>> + >>>> +# Type for the file on which we want to set a watch >>>> +type test_notify_file_t; >>>> +files_type(test_notify_file_t); >>>> + >>>> +# Domain for the process which CAN set a non-permission watch >>>> +type test_watch_t; >>>> +domain_type(test_watch_t); >>>> +unconfined_runs_test(test_watch_t); >>>> + >>>> +typeattribute test_watch_t test_notify_domain; >>>> +typeattribute test_watch_t testdomain; >>>> + >>>> +allow test_notify_domain self:capability sys_admin; >>>> + >>>> +allow test_watch_t test_notify_file_t:file { read write open watch }; >>>> + >>>> +# Domain for the process which CAN set a NON-access watch on a file >>>> +type test_perm_watch_t; >>>> +domain_type(test_perm_watch_t); >>>> +unconfined_runs_test(test_perm_watch_t); >>>> + >>>> +typeattribute test_perm_watch_t test_notify_domain; >>>> +typeattribute test_perm_watch_t testdomain; >>>> + >>>> +allow test_perm_watch_t test_notify_file_t:file { read write open watch watch_with_perm }; >>>> + >>>> +# Domain which CAN set a NON-perm watch which MAY read accesses >>>> +type test_read_watch_t; >>>> +domain_type(test_read_watch_t); >>>> +unconfined_runs_test(test_read_watch_t); >>>> + >>>> +typeattribute test_read_watch_t test_notify_domain; >>>> +typeattribute test_read_watch_t testdomain; >>>> + >>>> +allow test_read_watch_t test_notify_file_t:file { read write open watch watch_reads }; >>>> + >>>> +# Domain which CAN set any watch which CAN read accesses >>>> +type test_perm_read_watch_t; >>>> +domain_type(test_perm_read_watch_t); >>>> +unconfined_runs_test(test_perm_read_watch_t); >>>> + >>>> +typeattribute test_perm_read_watch_t test_notify_domain; >>>> +typeattribute test_perm_read_watch_t testdomain; >>>> + >>>> +allow test_perm_read_watch_t test_notify_file_t:file { read write open watch watch_with_perm watch_reads }; >>>> + >>>> +# Domain which CANNOT set any watches >>>> +type test_no_watch_t; >>>> +domain_type(test_no_watch_t); >>>> +unconfined_runs_test(test_no_watch_t); >>>> + >>>> +typeattribute test_no_watch_t test_notify_domain; >>>> +typeattribute test_no_watch_t testdomain; >>>> + >>>> +allow test_no_watch_t test_notify_file_t:file { read write open }; >>>> + >>>> +# Domain which has no write access but can watch >>>> +type test_rdonly_t; >>>> +domain_type(test_rdonly_t); >>>> +unconfined_runs_test(test_rdonly_t); >>>> + >>>> +typeattribute test_rdonly_t test_notify_domain; >>>> +typeattribute test_rdonly_t testdomain; >>>> + >>>> +allow test_rdonly_t test_notify_file_t:file { read open watch }; >>>> + >>>> +miscfiles_domain_entry_test_files(test_notify_domain); >>>> +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); >>>> diff --git a/tests/Makefile b/tests/Makefile >>>> index 63aa325..b99c96e 100644 >>>> --- a/tests/Makefile >>>> +++ b/tests/Makefile >>>> @@ -50,6 +50,10 @@ ifeq ($(shell grep "^SELINUX_INFINIBAND_PKEY_TEST=" infiniband_pkey/ibpkey_test. >>>> SUBDIRS += infiniband_pkey >>>> endif >>>> +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) >>>> +SUBDIRS+=notify >>>> +endif >>>> + >>>> ifeq ($(DISTRO),RHEL4) >>>> SUBDIRS:=$(filter-out bounds dyntrace dyntrans inet_socket mmap nnp_nosuid overlay unix_socket, $(SUBDIRS)) >>>> endif >>>> diff --git a/tests/notify/Makefile b/tests/notify/Makefile >>>> new file mode 100644 >>>> index 0000000..78c4b3b >>>> --- /dev/null >>>> +++ b/tests/notify/Makefile >>>> @@ -0,0 +1,5 @@ >>>> +TARGETS=test_inotify test_fanotify >>>> + >>>> +all: $(TARGETS) >>>> +clean: >>>> + rm -f $(TARGETS) >>>> diff --git a/tests/notify/test b/tests/notify/test >>>> new file mode 100755 >>>> index 0000000..21f03de >>>> --- /dev/null >>>> +++ b/tests/notify/test >>>> @@ -0,0 +1,101 @@ >>>> +#!/usr/bin/perl >>>> + >>>> +use Test; >>>> +BEGIN { plan tests => 14 } # number of tests to run >>>> + >>>> +# help the test script locate itself >>>> +$basedir = $0; >>>> +$basedir =~ s|(.*)/[^/]*|$1|; >>>> + >>>> +# Get rid of a testfile from last run if it's there (just in case) >>>> +system("rm -f $basedir/watch_me"); >>>> + >>>> +# Create a new test file >>>> +system("touch $basedir/watch_me"); >>>> +system("chcon -t test_notify_file_t $basedir/watch_me"); >>>> + >>>> +## TESTS >>>> + >>>> +## TEST BASIC WATCH PERMISSION >>>> +# Should be able to set inotify watch >>>> +$exit_val = >>>> + system("runcon -t test_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); >>>> +ok( $exit_val, 0 ); >>>> + >>>> +# Should be able to set non-permissions based fanotify watch >>>> +$exit_val = system( >>>> + "runcon -t test_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); >>>> +ok( $exit_val, 0 ); >>>> + >>>> +# Should NOT be able to set permission based fanotify watch >>>> +$exit_val = system( >>>> + "runcon -t test_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1"); >>>> +ok($exit_val); # this should fail >>>> + >>>> +# Should NOT be able to set read based fanotify watch >>>> +$exit_val = system( >>>> + "runcon -t test_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1"); >>>> +ok($exit_val); # this should fail >>>> + >>>> +# Should NOT be able to set read based inotify watch >>>> +$exit_val = system( >>>> + "runcon -t test_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1"); >>>> +ok($exit_val); # this should fail >>>> + >>>> +## TEST PERM WATCH >>>> +# Should be able to set permission based fanotify watch >>>> +$exit_val = system( >>>> +"runcon -t test_perm_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1" >>>> +); >>>> +ok( $exit_val, 0 ); >>>> + >>>> +# Should NOT be able to set watch of accesses >>>> +$exit_val = system( >>>> +"runcon -t test_perm_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1" >>>> +); >>>> +ok($exit_val); # this should fail >>>> + >>>> +## TEST READ NO PERM WATCH PERMSISSIONS >>>> +# Should NOT be able to set read and perm watch >>>> +$exit_val = system( >>>> +"runcon -t test_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" >>>> +); >>>> +ok($exit_val); # should fail >>>> + >>>> +# Should be able to set read inotify watch >>>> +$exit_val = system( >>>> +"runcon -t test_read_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1" >>>> +); >>>> +ok( $exit_val, 0 ); >>>> + >>>> +## TEST READ WITH PERM WATCH PERMSISSIONS >>>> +# Should be able to set read and perm watch >>>> +$exit_val = system( >>>> +"runcon -t test_perm_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" >>>> +); >>>> +ok( $exit_val, 0 ); >>>> + >>>> +## TEST NO WATCH PERMSISSIONS >>>> +# Should NOT be able to set inotify watch >>>> +$exit_val = system( >>>> + "runcon -t test_no_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); >>>> +ok($exit_val); # this should fail >>>> + >>>> +# Should NOT be able to set any fanotify watch >>>> +$exit_val = system( >>>> + "runcon -t test_no_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); >>>> +ok($exit_val); # this should fail >>>> + >>>> +## TEST READ ONLY >>>> +# Should NOT be able to get read-write descriptor >>>> +$exit_val = system( >>>> + "runcon -t test_rdonly_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); >>>> +ok($exit_val); # this should fail >>>> + >>>> +# Should be able to get read-write descriptor >>>> +$exit_val = system( >>>> + "runcon -t test_watch_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); >>>> +ok( $exit_val, 0 ); >>>> + >>>> +# Clean up test file >>>> +system("rm -f $basedir/watch_me"); >>>> diff --git a/tests/notify/test_fanotify.c b/tests/notify/test_fanotify.c >>>> new file mode 100644 >>>> index 0000000..fff773f >>>> --- /dev/null >>>> +++ b/tests/notify/test_fanotify.c >>>> @@ -0,0 +1,105 @@ >>>> +#define _GNU_SOURCE 1 >>>> + >>>> +#include <stdio.h> >>>> +#include <stdlib.h> >>>> + >>>> +#include <getopt.h> >>>> + >>>> +#include <fcntl.h> >>>> +#include <poll.h> >>>> +#include <sys/fanotify.h> >>>> +#include <unistd.h> >>>> + >>>> +void printUsage() >>>> +{ >>>> + fprintf(stderr, "Usage: test_fanotify [-p] [-r] [-l] file_name\n"); >>>> + exit(1); >>>> +} >>>> + >>>> +int main(int argc, char *argv[]) >>>> +{ >>>> + if (argc < 2) { >>>> + printUsage(); >>>> + } >>>> + >>>> + int fd, ret, arg; >>>> + int mask = FAN_OPEN; // default mask >>>> + int listening = 0; >>>> + >>>> + // the -p flag will test for watch_with_perm >>>> + // the mask used at mark will contain FAN_OPEN_PERM >>>> + // >>>> + // the -r flag will test for watching accesses to files for reads >>>> + // the mask will contain FAN_ACCESS >>>> + while ((arg = getopt(argc, argv, "prl")) != -1) { >>>> + switch (arg) { >>>> + case 'p': >>>> + mask |= FAN_OPEN_PERM; >>>> + break; >>>> + case 'r': >>>> + mask |= FAN_ACCESS; >>>> + break; >>>> + case 'l': >>>> + listening = 1; >>>> + break; >>>> + default: >>>> + printUsage(); >>>> + } >>>> + } >>>> + >>>> + // get file descriptor for new fanotify event queue >>>> + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); >>>> + if (fd < 0) { >>>> + perror("fanotify_init:bad file descriptor"); >>>> + exit(1); >>>> + } >>>> + >>>> + // mark a filesystem object and add mark to event queue >>>> + // get notifications on file opens, accesses, and closes >>>> + // use current working directory as base dir >>>> + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, AT_FDCWD, argv[optind]); >>>> + >>>> + if (ret < 0) { >>>> + perror("test_fanotify:watch denied"); >>>> + exit(1); >>>> + } >>>> + >>>> + // logic to actually listen for an event if the -l flag is passed >>>> + // this is used to test if an app with read-only access can get a read/write >>>> + // handle to the watched file >>>> + if (listening) { >>>> + if (fork() == 0) { // fork a child process to cause an event on the file >>>> + FILE *f; >>>> + >>>> + f = fopen(argv[optind], "r"); // open file for reading >>>> + fgetc(f); // read char from file >>>> + >>>> + fclose(f); >>>> + } else { // logic to watch for events and try to access file read/write >>>> + struct pollfd fds; >>>> + fds.fd = fd; >>>> + fds.events = POLLIN; >>>> + >>>> + while (listening) { >>>> + int polled = poll(&fds, 1, 1); >>>> + if (polled > 0) { >>>> + if (fds.revents & POLLIN) { >>>> + struct fanotify_event_metadata buff[200]; >>>> + >>>> + size_t len = read(fd, (void *)&buff, sizeof(buff)); >>>> + if (len == -1) { >>>> + perror("test_fanotify:can't open file"); >>>> + exit(1); >>>> + } else { >>>> + listening = 0; >>>> + break; >>>> + } >>>> + } >>>> + } else if (polled == -1) { >>>> + listening = 0; >>>> + } >>>> + } >>>> + } >>>> + } >>>> + exit(0); >>>> +} >>>> diff --git a/tests/notify/test_inotify.c b/tests/notify/test_inotify.c >>>> new file mode 100644 >>>> index 0000000..17c3565 >>>> --- /dev/null >>>> +++ b/tests/notify/test_inotify.c >>>> @@ -0,0 +1,43 @@ >>>> +#include <stdio.h> >>>> +#include <stdlib.h> >>>> +#include <sys/inotify.h> >>>> +#include <getopt.h> >>>> + >>>> +int main(int argc, char *argv[]) >>>> +{ >>>> + if (argc < 2) { >>>> + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); >>>> + exit(1); >>>> + } >>>> + >>>> + int fd, wd, arg; >>>> + int mask = IN_MODIFY; >>>> + >>>> + while ((arg = getopt(argc, argv, "pr")) != -1) { >>>> + switch (arg) { >>>> + case 'r': >>>> + mask |= IN_ACCESS; >>>> + break; >>>> + default: >>>> + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); >>>> + exit(1); >>>> + } >>>> + } >>>> + >>>> + // get new file descriptor for inotify access >>>> + fd = inotify_init(); >>>> + if (fd < 0) { >>>> + perror("inotify_init:bad file descriptor"); >>>> + exit(1); >>>> + } >>>> + >>>> + // set watch on file and get watch descriptor for accessing events on it >>>> + wd = inotify_add_watch(fd, argv[optind], mask); >>>> + >>>> + if (wd < 0) { >>>> + perror("test_inotify:watch denied"); >>>> + exit(1); >>>> + } >>>> + >>>> + exit(0); >>>> +} >>>> -- >>>> 2.21.0 >>>> >>> >> >
On 9/10/19 10:40 AM, Stephen Smalley wrote: > On 9/10/19 10:15 AM, Dominick Grift wrote: >> On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: >>> On 9/10/19 1:59 AM, Dominick Grift wrote: >>>> On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: >>>>> Added a suite to test permissions for setting inotify and fanotify >>>>> watches >>>>> on filesystem objects. Tests watch, watch_with_perm, and >>>>> watch_reads permissions. >>>> >>>> Ive also "tested" the fsnotify patch. And my tests indicate that >>>> this might cause issues: >>>> >>>> I added the access vectors to my policy, but on older systems >>>> (debian 10) cron fails to start >>>> cron needs the "entrypoint" permission on /etc/crontab but it looks >>>> like appending the "watch" access vectors to common-file disrupted >>>> the ordering >>>> The result is that now i have to allow cron to "watch_read" >>>> /etc/crontab even though the neither kernel nor selinux user space >>>> are aware of the fsnotify access vectors >>>> It seems the cron selinux code got confused and now thinks >>>> watch_read is entrypoint (its using selinux code to determine >>>> whether it can manually transition to cronjob domains on crontabs) >>>> >>>> I am hoping this issue with resolve itself on systems with kernels >>>> and user spaces that suppose fsnotify. >>>> However unless i am overlooking something this is still likely to >>>> disrupt compatibility >>> >>> So, IIUC, the issue is that: >>> a) older cron was directly using the fixed FILE__ENTRYPOINT >>> definition from >>> libselinux in a security_compute_av() call rather than dynamically >>> looking >>> up entrypoint permission, >>> b) the value of the file entrypoint permission in policy has changed >>> because >>> you updated your policy and chose to place the watch* permissions in the >>> common file definition to match the kernel. >>> >>> Note that you could have instead sprinkled copies of the watch* >>> permissions >>> across all of the individual file/dir/*_file classes and placed them >>> at the >>> end of the classes if you wanted to avoid this compatibility issue. The >>> policy and kernel definitions no longer need to be identical; the kernel >>> will dynamically map between them for its own permission checks. >>> >>> Also, this should have already been broken for you when map >>> permission was >>> added, which would have shown up as execute_no_trans being checked >>> instead >>> of entrypoint. This was already filed as a bug on cron in debian here: >>> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 >>> >>> So, wrt compatibility, IIUC: >>> - the kernel change does not break compatibility for old policy + old >>> userspace, >>> - new policy can choose to add the new permissions in a >>> backward-compatible >>> manner if desired, although refpolicy has already chosen not to do >>> this for >>> map permission, >>> - the offending code in cron produces build warnings that were >>> introduced in >>> 2014 in libselinux to update their code to use the dynamic class/perm >>> mapping support, which would resolve the issue. >> >> this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): >> https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d >> >> >> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x --common >> common_file >> >> Commons: 1 >> common common_file >> { >> append >> lock >> mounton >> unlink >> read >> create >> quotaon >> execute >> setattr >> map >> relabelto >> rename >> link >> ioctl >> getattr >> relabelfrom >> } >> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile >> >> Classes: 1 >> class file >> inherits common_file >> { >> execmod >> watch >> write >> watch_reads >> execute_no_trans >> watch_mount >> watch_with_perm >> open >> watch_sb >> audit_access >> entrypoint >> } > > If you want to preserve compatibility with userspace using fixed > definitions of FILE__ENTRYPOINT, then you have to insert any new file > permissions after the current entrypoint permission in the class file. > So watch and friends have to go after it, not before it. > > Also, since the kernel always uses FILE__WATCH* in the check code rather > than distinguishing by class, the watch* permissions need to be at the > same offset in all of the file classes. The same is true of the other > file permissions. It looks like you may have other permissions out of > sync across the file classes e.g. execmod, open, audit_access, that need > to be aligned or the kernel could check the wrong permission. Sorry, the last para isn't correct - it should get mapped correctly per class. But you do need to add the permissions after entrypoint in the file class to avoid displacing its value. > >> >>> >>>> >>>>> >>>>> Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> >>>>> --- >>>>> policy/Makefile | 4 ++ >>>>> policy/test_notify.te | 74 ++++++++++++++++++++++++ >>>>> tests/Makefile | 4 ++ >>>>> tests/notify/Makefile | 5 ++ >>>>> tests/notify/test | 101 >>>>> +++++++++++++++++++++++++++++++++ >>>>> tests/notify/test_fanotify.c | 105 >>>>> +++++++++++++++++++++++++++++++++++ >>>>> tests/notify/test_inotify.c | 43 ++++++++++++++ >>>>> 7 files changed, 336 insertions(+) >>>>> create mode 100644 policy/test_notify.te >>>>> create mode 100644 tests/notify/Makefile >>>>> create mode 100755 tests/notify/test >>>>> create mode 100644 tests/notify/test_fanotify.c >>>>> create mode 100644 tests/notify/test_inotify.c >>>>> >>>>> diff --git a/policy/Makefile b/policy/Makefile >>>>> index 305b572..65f88c5 100644 >>>>> --- a/policy/Makefile >>>>> +++ b/policy/Makefile >>>>> @@ -71,6 +71,10 @@ ifeq ($(shell grep -q >>>>> corenet_sctp_bind_all_nodes $(POLDEV)/include/kernel/coren >>>>> TARGETS += test_sctp.te >>>>> endif >>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>> $(POLDEV)/include/support/all_perms.spt && echo true),true) >>>>> +TARGETS+=test_notify.te >>>>> +endif >>>>> + >>>>> ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) >>>>> TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te, $(TARGETS)) >>>>> endif >>>>> diff --git a/policy/test_notify.te b/policy/test_notify.te >>>>> new file mode 100644 >>>>> index 0000000..8ba6f1a >>>>> --- /dev/null >>>>> +++ b/policy/test_notify.te >>>>> @@ -0,0 +1,74 @@ >>>>> +#################################################### >>>>> +# Policy for testing inoftify and fanotify watches # >>>>> +#################################################### >>>>> + >>>>> +attribute test_notify_domain; >>>>> + >>>>> +# Type for the file on which we want to set a watch >>>>> +type test_notify_file_t; >>>>> +files_type(test_notify_file_t); >>>>> + >>>>> +# Domain for the process which CAN set a non-permission watch >>>>> +type test_watch_t; >>>>> +domain_type(test_watch_t); >>>>> +unconfined_runs_test(test_watch_t); >>>>> + >>>>> +typeattribute test_watch_t test_notify_domain; >>>>> +typeattribute test_watch_t testdomain; >>>>> + >>>>> +allow test_notify_domain self:capability sys_admin; >>>>> + >>>>> +allow test_watch_t test_notify_file_t:file { read write open watch }; >>>>> + >>>>> +# Domain for the process which CAN set a NON-access watch on a file >>>>> +type test_perm_watch_t; >>>>> +domain_type(test_perm_watch_t); >>>>> +unconfined_runs_test(test_perm_watch_t); >>>>> + >>>>> +typeattribute test_perm_watch_t test_notify_domain; >>>>> +typeattribute test_perm_watch_t testdomain; >>>>> + >>>>> +allow test_perm_watch_t test_notify_file_t:file { read write open >>>>> watch watch_with_perm }; >>>>> + >>>>> +# Domain which CAN set a NON-perm watch which MAY read accesses >>>>> +type test_read_watch_t; >>>>> +domain_type(test_read_watch_t); >>>>> +unconfined_runs_test(test_read_watch_t); >>>>> + >>>>> +typeattribute test_read_watch_t test_notify_domain; >>>>> +typeattribute test_read_watch_t testdomain; >>>>> + >>>>> +allow test_read_watch_t test_notify_file_t:file { read write open >>>>> watch watch_reads }; >>>>> + >>>>> +# Domain which CAN set any watch which CAN read accesses >>>>> +type test_perm_read_watch_t; >>>>> +domain_type(test_perm_read_watch_t); >>>>> +unconfined_runs_test(test_perm_read_watch_t); >>>>> + >>>>> +typeattribute test_perm_read_watch_t test_notify_domain; >>>>> +typeattribute test_perm_read_watch_t testdomain; >>>>> + >>>>> +allow test_perm_read_watch_t test_notify_file_t:file { read write >>>>> open watch watch_with_perm watch_reads }; >>>>> + >>>>> +# Domain which CANNOT set any watches >>>>> +type test_no_watch_t; >>>>> +domain_type(test_no_watch_t); >>>>> +unconfined_runs_test(test_no_watch_t); >>>>> + >>>>> +typeattribute test_no_watch_t test_notify_domain; >>>>> +typeattribute test_no_watch_t testdomain; >>>>> + >>>>> +allow test_no_watch_t test_notify_file_t:file { read write open }; >>>>> + >>>>> +# Domain which has no write access but can watch >>>>> +type test_rdonly_t; >>>>> +domain_type(test_rdonly_t); >>>>> +unconfined_runs_test(test_rdonly_t); >>>>> + >>>>> +typeattribute test_rdonly_t test_notify_domain; >>>>> +typeattribute test_rdonly_t testdomain; >>>>> + >>>>> +allow test_rdonly_t test_notify_file_t:file { read open watch }; >>>>> + >>>>> +miscfiles_domain_entry_test_files(test_notify_domain); >>>>> +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); >>>>> diff --git a/tests/Makefile b/tests/Makefile >>>>> index 63aa325..b99c96e 100644 >>>>> --- a/tests/Makefile >>>>> +++ b/tests/Makefile >>>>> @@ -50,6 +50,10 @@ ifeq ($(shell grep >>>>> "^SELINUX_INFINIBAND_PKEY_TEST=" infiniband_pkey/ibpkey_test. >>>>> SUBDIRS += infiniband_pkey >>>>> endif >>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>> $(POLDEV)/include/support/all_perms.spt && echo true),true) >>>>> +SUBDIRS+=notify >>>>> +endif >>>>> + >>>>> ifeq ($(DISTRO),RHEL4) >>>>> SUBDIRS:=$(filter-out bounds dyntrace dyntrans inet_socket >>>>> mmap nnp_nosuid overlay unix_socket, $(SUBDIRS)) >>>>> endif >>>>> diff --git a/tests/notify/Makefile b/tests/notify/Makefile >>>>> new file mode 100644 >>>>> index 0000000..78c4b3b >>>>> --- /dev/null >>>>> +++ b/tests/notify/Makefile >>>>> @@ -0,0 +1,5 @@ >>>>> +TARGETS=test_inotify test_fanotify >>>>> + >>>>> +all: $(TARGETS) >>>>> +clean: >>>>> + rm -f $(TARGETS) >>>>> diff --git a/tests/notify/test b/tests/notify/test >>>>> new file mode 100755 >>>>> index 0000000..21f03de >>>>> --- /dev/null >>>>> +++ b/tests/notify/test >>>>> @@ -0,0 +1,101 @@ >>>>> +#!/usr/bin/perl >>>>> + >>>>> +use Test; >>>>> +BEGIN { plan tests => 14 } # number of tests to run >>>>> + >>>>> +# help the test script locate itself >>>>> +$basedir = $0; >>>>> +$basedir =~ s|(.*)/[^/]*|$1|; >>>>> + >>>>> +# Get rid of a testfile from last run if it's there (just in case) >>>>> +system("rm -f $basedir/watch_me"); >>>>> + >>>>> +# Create a new test file >>>>> +system("touch $basedir/watch_me"); >>>>> +system("chcon -t test_notify_file_t $basedir/watch_me"); >>>>> + >>>>> +## TESTS >>>>> + >>>>> +## TEST BASIC WATCH PERMISSION >>>>> +# Should be able to set inotify watch >>>>> +$exit_val = >>>>> + system("runcon -t test_watch_t $basedir/test_inotify >>>>> $basedir/watch_me 2>&1"); >>>>> +ok( $exit_val, 0 ); >>>>> + >>>>> +# Should be able to set non-permissions based fanotify watch >>>>> +$exit_val = system( >>>>> + "runcon -t test_watch_t $basedir/test_fanotify >>>>> $basedir/watch_me 2>&1"); >>>>> +ok( $exit_val, 0 ); >>>>> + >>>>> +# Should NOT be able to set permission based fanotify watch >>>>> +$exit_val = system( >>>>> + "runcon -t test_watch_t $basedir/test_fanotify -p >>>>> $basedir/watch_me 2>&1"); >>>>> +ok($exit_val); # this should fail >>>>> + >>>>> +# Should NOT be able to set read based fanotify watch >>>>> +$exit_val = system( >>>>> + "runcon -t test_watch_t $basedir/test_fanotify -r >>>>> $basedir/watch_me 2>&1"); >>>>> +ok($exit_val); # this should fail >>>>> + >>>>> +# Should NOT be able to set read based inotify watch >>>>> +$exit_val = system( >>>>> + "runcon -t test_watch_t $basedir/test_inotify -r >>>>> $basedir/watch_me 2>&1"); >>>>> +ok($exit_val); # this should fail >>>>> + >>>>> +## TEST PERM WATCH >>>>> +# Should be able to set permission based fanotify watch >>>>> +$exit_val = system( >>>>> +"runcon -t test_perm_watch_t $basedir/test_fanotify -p >>>>> $basedir/watch_me 2>&1" >>>>> +); >>>>> +ok( $exit_val, 0 ); >>>>> + >>>>> +# Should NOT be able to set watch of accesses >>>>> +$exit_val = system( >>>>> +"runcon -t test_perm_watch_t $basedir/test_fanotify -r >>>>> $basedir/watch_me 2>&1" >>>>> +); >>>>> +ok($exit_val); # this should fail >>>>> + >>>>> +## TEST READ NO PERM WATCH PERMSISSIONS >>>>> +# Should NOT be able to set read and perm watch >>>>> +$exit_val = system( >>>>> +"runcon -t test_read_watch_t $basedir/test_fanotify -p -r >>>>> $basedir/watch_me 2>&1" >>>>> +); >>>>> +ok($exit_val); # should fail >>>>> + >>>>> +# Should be able to set read inotify watch >>>>> +$exit_val = system( >>>>> +"runcon -t test_read_watch_t $basedir/test_inotify -r >>>>> $basedir/watch_me 2>&1" >>>>> +); >>>>> +ok( $exit_val, 0 ); >>>>> + >>>>> +## TEST READ WITH PERM WATCH PERMSISSIONS >>>>> +# Should be able to set read and perm watch >>>>> +$exit_val = system( >>>>> +"runcon -t test_perm_read_watch_t $basedir/test_fanotify -p -r >>>>> $basedir/watch_me 2>&1" >>>>> +); >>>>> +ok( $exit_val, 0 ); >>>>> + >>>>> +## TEST NO WATCH PERMSISSIONS >>>>> +# Should NOT be able to set inotify watch >>>>> +$exit_val = system( >>>>> + "runcon -t test_no_watch_t $basedir/test_inotify >>>>> $basedir/watch_me 2>&1"); >>>>> +ok($exit_val); # this should fail >>>>> + >>>>> +# Should NOT be able to set any fanotify watch >>>>> +$exit_val = system( >>>>> + "runcon -t test_no_watch_t $basedir/test_fanotify >>>>> $basedir/watch_me 2>&1"); >>>>> +ok($exit_val); # this should fail >>>>> + >>>>> +## TEST READ ONLY >>>>> +# Should NOT be able to get read-write descriptor >>>>> +$exit_val = system( >>>>> + "runcon -t test_rdonly_t $basedir/test_fanotify -l >>>>> $basedir/watch_me 2>&1"); >>>>> +ok($exit_val); # this should fail >>>>> + >>>>> +# Should be able to get read-write descriptor >>>>> +$exit_val = system( >>>>> + "runcon -t test_watch_t $basedir/test_fanotify -l >>>>> $basedir/watch_me 2>&1"); >>>>> +ok( $exit_val, 0 ); >>>>> + >>>>> +# Clean up test file >>>>> +system("rm -f $basedir/watch_me"); >>>>> diff --git a/tests/notify/test_fanotify.c >>>>> b/tests/notify/test_fanotify.c >>>>> new file mode 100644 >>>>> index 0000000..fff773f >>>>> --- /dev/null >>>>> +++ b/tests/notify/test_fanotify.c >>>>> @@ -0,0 +1,105 @@ >>>>> +#define _GNU_SOURCE 1 >>>>> + >>>>> +#include <stdio.h> >>>>> +#include <stdlib.h> >>>>> + >>>>> +#include <getopt.h> >>>>> + >>>>> +#include <fcntl.h> >>>>> +#include <poll.h> >>>>> +#include <sys/fanotify.h> >>>>> +#include <unistd.h> >>>>> + >>>>> +void printUsage() >>>>> +{ >>>>> + fprintf(stderr, "Usage: test_fanotify [-p] [-r] [-l] >>>>> file_name\n"); >>>>> + exit(1); >>>>> +} >>>>> + >>>>> +int main(int argc, char *argv[]) >>>>> +{ >>>>> + if (argc < 2) { >>>>> + printUsage(); >>>>> + } >>>>> + >>>>> + int fd, ret, arg; >>>>> + int mask = FAN_OPEN; // default mask >>>>> + int listening = 0; >>>>> + >>>>> + // the -p flag will test for watch_with_perm >>>>> + // the mask used at mark will contain FAN_OPEN_PERM >>>>> + // >>>>> + // the -r flag will test for watching accesses to files for reads >>>>> + // the mask will contain FAN_ACCESS >>>>> + while ((arg = getopt(argc, argv, "prl")) != -1) { >>>>> + switch (arg) { >>>>> + case 'p': >>>>> + mask |= FAN_OPEN_PERM; >>>>> + break; >>>>> + case 'r': >>>>> + mask |= FAN_ACCESS; >>>>> + break; >>>>> + case 'l': >>>>> + listening = 1; >>>>> + break; >>>>> + default: >>>>> + printUsage(); >>>>> + } >>>>> + } >>>>> + >>>>> + // get file descriptor for new fanotify event queue >>>>> + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); >>>>> + if (fd < 0) { >>>>> + perror("fanotify_init:bad file descriptor"); >>>>> + exit(1); >>>>> + } >>>>> + >>>>> + // mark a filesystem object and add mark to event queue >>>>> + // get notifications on file opens, accesses, and closes >>>>> + // use current working directory as base dir >>>>> + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, AT_FDCWD, >>>>> argv[optind]); >>>>> + >>>>> + if (ret < 0) { >>>>> + perror("test_fanotify:watch denied"); >>>>> + exit(1); >>>>> + } >>>>> + >>>>> + // logic to actually listen for an event if the -l flag is passed >>>>> + // this is used to test if an app with read-only access can >>>>> get a read/write >>>>> + // handle to the watched file >>>>> + if (listening) { >>>>> + if (fork() == 0) { // fork a child process to cause an >>>>> event on the file >>>>> + FILE *f; >>>>> + >>>>> + f = fopen(argv[optind], "r"); // open file for reading >>>>> + fgetc(f); // read char from file >>>>> + >>>>> + fclose(f); >>>>> + } else { // logic to watch for events and try to access >>>>> file read/write >>>>> + struct pollfd fds; >>>>> + fds.fd = fd; >>>>> + fds.events = POLLIN; >>>>> + >>>>> + while (listening) { >>>>> + int polled = poll(&fds, 1, 1); >>>>> + if (polled > 0) { >>>>> + if (fds.revents & POLLIN) { >>>>> + struct fanotify_event_metadata buff[200]; >>>>> + >>>>> + size_t len = read(fd, (void *)&buff, >>>>> sizeof(buff)); >>>>> + if (len == -1) { >>>>> + perror("test_fanotify:can't open file"); >>>>> + exit(1); >>>>> + } else { >>>>> + listening = 0; >>>>> + break; >>>>> + } >>>>> + } >>>>> + } else if (polled == -1) { >>>>> + listening = 0; >>>>> + } >>>>> + } >>>>> + } >>>>> + } >>>>> + exit(0); >>>>> +} >>>>> diff --git a/tests/notify/test_inotify.c b/tests/notify/test_inotify.c >>>>> new file mode 100644 >>>>> index 0000000..17c3565 >>>>> --- /dev/null >>>>> +++ b/tests/notify/test_inotify.c >>>>> @@ -0,0 +1,43 @@ >>>>> +#include <stdio.h> >>>>> +#include <stdlib.h> >>>>> +#include <sys/inotify.h> >>>>> +#include <getopt.h> >>>>> + >>>>> +int main(int argc, char *argv[]) >>>>> +{ >>>>> + if (argc < 2) { >>>>> + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); >>>>> + exit(1); >>>>> + } >>>>> + >>>>> + int fd, wd, arg; >>>>> + int mask = IN_MODIFY; >>>>> + >>>>> + while ((arg = getopt(argc, argv, "pr")) != -1) { >>>>> + switch (arg) { >>>>> + case 'r': >>>>> + mask |= IN_ACCESS; >>>>> + break; >>>>> + default: >>>>> + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); >>>>> + exit(1); >>>>> + } >>>>> + } >>>>> + >>>>> + // get new file descriptor for inotify access >>>>> + fd = inotify_init(); >>>>> + if (fd < 0) { >>>>> + perror("inotify_init:bad file descriptor"); >>>>> + exit(1); >>>>> + } >>>>> + >>>>> + // set watch on file and get watch descriptor for accessing >>>>> events on it >>>>> + wd = inotify_add_watch(fd, argv[optind], mask); >>>>> + >>>>> + if (wd < 0) { >>>>> + perror("test_inotify:watch denied"); >>>>> + exit(1); >>>>> + } >>>>> + >>>>> + exit(0); >>>>> +} >>>>> -- >>>>> 2.21.0 >>>>> >>>> >>> >> >
On 9/10/19 10:54 AM, Stephen Smalley wrote: > On 9/10/19 10:40 AM, Stephen Smalley wrote: >> On 9/10/19 10:15 AM, Dominick Grift wrote: >>> On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: >>>> On 9/10/19 1:59 AM, Dominick Grift wrote: >>>>> On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: >>>>>> Added a suite to test permissions for setting inotify and fanotify >>>>>> watches >>>>>> on filesystem objects. Tests watch, watch_with_perm, and >>>>>> watch_reads permissions. >>>>> >>>>> Ive also "tested" the fsnotify patch. And my tests indicate that >>>>> this might cause issues: >>>>> >>>>> I added the access vectors to my policy, but on older systems >>>>> (debian 10) cron fails to start >>>>> cron needs the "entrypoint" permission on /etc/crontab but it looks >>>>> like appending the "watch" access vectors to common-file disrupted >>>>> the ordering >>>>> The result is that now i have to allow cron to "watch_read" >>>>> /etc/crontab even though the neither kernel nor selinux user space >>>>> are aware of the fsnotify access vectors >>>>> It seems the cron selinux code got confused and now thinks >>>>> watch_read is entrypoint (its using selinux code to determine >>>>> whether it can manually transition to cronjob domains on crontabs) >>>>> >>>>> I am hoping this issue with resolve itself on systems with kernels >>>>> and user spaces that suppose fsnotify. >>>>> However unless i am overlooking something this is still likely to >>>>> disrupt compatibility >>>> >>>> So, IIUC, the issue is that: >>>> a) older cron was directly using the fixed FILE__ENTRYPOINT >>>> definition from >>>> libselinux in a security_compute_av() call rather than dynamically >>>> looking >>>> up entrypoint permission, >>>> b) the value of the file entrypoint permission in policy has changed >>>> because >>>> you updated your policy and chose to place the watch* permissions in >>>> the >>>> common file definition to match the kernel. >>>> >>>> Note that you could have instead sprinkled copies of the watch* >>>> permissions >>>> across all of the individual file/dir/*_file classes and placed them >>>> at the >>>> end of the classes if you wanted to avoid this compatibility issue. >>>> The >>>> policy and kernel definitions no longer need to be identical; the >>>> kernel >>>> will dynamically map between them for its own permission checks. >>>> >>>> Also, this should have already been broken for you when map >>>> permission was >>>> added, which would have shown up as execute_no_trans being checked >>>> instead >>>> of entrypoint. This was already filed as a bug on cron in debian here: >>>> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 >>>> >>>> So, wrt compatibility, IIUC: >>>> - the kernel change does not break compatibility for old policy + old >>>> userspace, >>>> - new policy can choose to add the new permissions in a >>>> backward-compatible >>>> manner if desired, although refpolicy has already chosen not to do >>>> this for >>>> map permission, >>>> - the offending code in cron produces build warnings that were >>>> introduced in >>>> 2014 in libselinux to update their code to use the dynamic class/perm >>>> mapping support, which would resolve the issue. >>> >>> this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): >>> https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d >>> >>> >>> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x --common >>> common_file >>> >>> Commons: 1 >>> common common_file >>> { >>> append >>> lock >>> mounton >>> unlink >>> read >>> create >>> quotaon >>> execute >>> setattr >>> map >>> relabelto >>> rename >>> link >>> ioctl >>> getattr >>> relabelfrom >>> } >>> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile >>> >>> Classes: 1 >>> class file >>> inherits common_file >>> { >>> execmod >>> watch >>> write >>> watch_reads >>> execute_no_trans >>> watch_mount >>> watch_with_perm >>> open >>> watch_sb >>> audit_access >>> entrypoint >>> } >> >> If you want to preserve compatibility with userspace using fixed >> definitions of FILE__ENTRYPOINT, then you have to insert any new file >> permissions after the current entrypoint permission in the class file. >> So watch and friends have to go after it, not before it. >> >> Also, since the kernel always uses FILE__WATCH* in the check code >> rather than distinguishing by class, the watch* permissions need to be >> at the same offset in all of the file classes. The same is true of >> the other file permissions. It looks like you may have other >> permissions out of sync across the file classes e.g. execmod, open, >> audit_access, that need to be aligned or the kernel could check the >> wrong permission. > > Sorry, the last para isn't correct - it should get mapped correctly per > class. But you do need to add the permissions after entrypoint in the > file class to avoid displacing its value. Also, it looks like your file class permission order differs in other incompatible ways. If you want it to be compatible with the deprecated libselinux headers, the requisite order would be: class file inherits common_file { execute_no_trans entrypoint execmod open audit_access map } > >> >>> >>>> >>>>> >>>>>> >>>>>> Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> >>>>>> --- >>>>>> policy/Makefile | 4 ++ >>>>>> policy/test_notify.te | 74 ++++++++++++++++++++++++ >>>>>> tests/Makefile | 4 ++ >>>>>> tests/notify/Makefile | 5 ++ >>>>>> tests/notify/test | 101 >>>>>> +++++++++++++++++++++++++++++++++ >>>>>> tests/notify/test_fanotify.c | 105 >>>>>> +++++++++++++++++++++++++++++++++++ >>>>>> tests/notify/test_inotify.c | 43 ++++++++++++++ >>>>>> 7 files changed, 336 insertions(+) >>>>>> create mode 100644 policy/test_notify.te >>>>>> create mode 100644 tests/notify/Makefile >>>>>> create mode 100755 tests/notify/test >>>>>> create mode 100644 tests/notify/test_fanotify.c >>>>>> create mode 100644 tests/notify/test_inotify.c >>>>>> >>>>>> diff --git a/policy/Makefile b/policy/Makefile >>>>>> index 305b572..65f88c5 100644 >>>>>> --- a/policy/Makefile >>>>>> +++ b/policy/Makefile >>>>>> @@ -71,6 +71,10 @@ ifeq ($(shell grep -q >>>>>> corenet_sctp_bind_all_nodes $(POLDEV)/include/kernel/coren >>>>>> TARGETS += test_sctp.te >>>>>> endif >>>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>>> $(POLDEV)/include/support/all_perms.spt && echo true),true) >>>>>> +TARGETS+=test_notify.te >>>>>> +endif >>>>>> + >>>>>> ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) >>>>>> TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te, >>>>>> $(TARGETS)) >>>>>> endif >>>>>> diff --git a/policy/test_notify.te b/policy/test_notify.te >>>>>> new file mode 100644 >>>>>> index 0000000..8ba6f1a >>>>>> --- /dev/null >>>>>> +++ b/policy/test_notify.te >>>>>> @@ -0,0 +1,74 @@ >>>>>> +#################################################### >>>>>> +# Policy for testing inoftify and fanotify watches # >>>>>> +#################################################### >>>>>> + >>>>>> +attribute test_notify_domain; >>>>>> + >>>>>> +# Type for the file on which we want to set a watch >>>>>> +type test_notify_file_t; >>>>>> +files_type(test_notify_file_t); >>>>>> + >>>>>> +# Domain for the process which CAN set a non-permission watch >>>>>> +type test_watch_t; >>>>>> +domain_type(test_watch_t); >>>>>> +unconfined_runs_test(test_watch_t); >>>>>> + >>>>>> +typeattribute test_watch_t test_notify_domain; >>>>>> +typeattribute test_watch_t testdomain; >>>>>> + >>>>>> +allow test_notify_domain self:capability sys_admin; >>>>>> + >>>>>> +allow test_watch_t test_notify_file_t:file { read write open >>>>>> watch }; >>>>>> + >>>>>> +# Domain for the process which CAN set a NON-access watch on a file >>>>>> +type test_perm_watch_t; >>>>>> +domain_type(test_perm_watch_t); >>>>>> +unconfined_runs_test(test_perm_watch_t); >>>>>> + >>>>>> +typeattribute test_perm_watch_t test_notify_domain; >>>>>> +typeattribute test_perm_watch_t testdomain; >>>>>> + >>>>>> +allow test_perm_watch_t test_notify_file_t:file { read write open >>>>>> watch watch_with_perm }; >>>>>> + >>>>>> +# Domain which CAN set a NON-perm watch which MAY read accesses >>>>>> +type test_read_watch_t; >>>>>> +domain_type(test_read_watch_t); >>>>>> +unconfined_runs_test(test_read_watch_t); >>>>>> + >>>>>> +typeattribute test_read_watch_t test_notify_domain; >>>>>> +typeattribute test_read_watch_t testdomain; >>>>>> + >>>>>> +allow test_read_watch_t test_notify_file_t:file { read write open >>>>>> watch watch_reads }; >>>>>> + >>>>>> +# Domain which CAN set any watch which CAN read accesses >>>>>> +type test_perm_read_watch_t; >>>>>> +domain_type(test_perm_read_watch_t); >>>>>> +unconfined_runs_test(test_perm_read_watch_t); >>>>>> + >>>>>> +typeattribute test_perm_read_watch_t test_notify_domain; >>>>>> +typeattribute test_perm_read_watch_t testdomain; >>>>>> + >>>>>> +allow test_perm_read_watch_t test_notify_file_t:file { read write >>>>>> open watch watch_with_perm watch_reads }; >>>>>> + >>>>>> +# Domain which CANNOT set any watches >>>>>> +type test_no_watch_t; >>>>>> +domain_type(test_no_watch_t); >>>>>> +unconfined_runs_test(test_no_watch_t); >>>>>> + >>>>>> +typeattribute test_no_watch_t test_notify_domain; >>>>>> +typeattribute test_no_watch_t testdomain; >>>>>> + >>>>>> +allow test_no_watch_t test_notify_file_t:file { read write open }; >>>>>> + >>>>>> +# Domain which has no write access but can watch >>>>>> +type test_rdonly_t; >>>>>> +domain_type(test_rdonly_t); >>>>>> +unconfined_runs_test(test_rdonly_t); >>>>>> + >>>>>> +typeattribute test_rdonly_t test_notify_domain; >>>>>> +typeattribute test_rdonly_t testdomain; >>>>>> + >>>>>> +allow test_rdonly_t test_notify_file_t:file { read open watch }; >>>>>> + >>>>>> +miscfiles_domain_entry_test_files(test_notify_domain); >>>>>> +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); >>>>>> diff --git a/tests/Makefile b/tests/Makefile >>>>>> index 63aa325..b99c96e 100644 >>>>>> --- a/tests/Makefile >>>>>> +++ b/tests/Makefile >>>>>> @@ -50,6 +50,10 @@ ifeq ($(shell grep >>>>>> "^SELINUX_INFINIBAND_PKEY_TEST=" infiniband_pkey/ibpkey_test. >>>>>> SUBDIRS += infiniband_pkey >>>>>> endif >>>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>>> $(POLDEV)/include/support/all_perms.spt && echo true),true) >>>>>> +SUBDIRS+=notify >>>>>> +endif >>>>>> + >>>>>> ifeq ($(DISTRO),RHEL4) >>>>>> SUBDIRS:=$(filter-out bounds dyntrace dyntrans inet_socket >>>>>> mmap nnp_nosuid overlay unix_socket, $(SUBDIRS)) >>>>>> endif >>>>>> diff --git a/tests/notify/Makefile b/tests/notify/Makefile >>>>>> new file mode 100644 >>>>>> index 0000000..78c4b3b >>>>>> --- /dev/null >>>>>> +++ b/tests/notify/Makefile >>>>>> @@ -0,0 +1,5 @@ >>>>>> +TARGETS=test_inotify test_fanotify >>>>>> + >>>>>> +all: $(TARGETS) >>>>>> +clean: >>>>>> + rm -f $(TARGETS) >>>>>> diff --git a/tests/notify/test b/tests/notify/test >>>>>> new file mode 100755 >>>>>> index 0000000..21f03de >>>>>> --- /dev/null >>>>>> +++ b/tests/notify/test >>>>>> @@ -0,0 +1,101 @@ >>>>>> +#!/usr/bin/perl >>>>>> + >>>>>> +use Test; >>>>>> +BEGIN { plan tests => 14 } # number of tests to run >>>>>> + >>>>>> +# help the test script locate itself >>>>>> +$basedir = $0; >>>>>> +$basedir =~ s|(.*)/[^/]*|$1|; >>>>>> + >>>>>> +# Get rid of a testfile from last run if it's there (just in case) >>>>>> +system("rm -f $basedir/watch_me"); >>>>>> + >>>>>> +# Create a new test file >>>>>> +system("touch $basedir/watch_me"); >>>>>> +system("chcon -t test_notify_file_t $basedir/watch_me"); >>>>>> + >>>>>> +## TESTS >>>>>> + >>>>>> +## TEST BASIC WATCH PERMISSION >>>>>> +# Should be able to set inotify watch >>>>>> +$exit_val = >>>>>> + system("runcon -t test_watch_t $basedir/test_inotify >>>>>> $basedir/watch_me 2>&1"); >>>>>> +ok( $exit_val, 0 ); >>>>>> + >>>>>> +# Should be able to set non-permissions based fanotify watch >>>>>> +$exit_val = system( >>>>>> + "runcon -t test_watch_t $basedir/test_fanotify >>>>>> $basedir/watch_me 2>&1"); >>>>>> +ok( $exit_val, 0 ); >>>>>> + >>>>>> +# Should NOT be able to set permission based fanotify watch >>>>>> +$exit_val = system( >>>>>> + "runcon -t test_watch_t $basedir/test_fanotify -p >>>>>> $basedir/watch_me 2>&1"); >>>>>> +ok($exit_val); # this should fail >>>>>> + >>>>>> +# Should NOT be able to set read based fanotify watch >>>>>> +$exit_val = system( >>>>>> + "runcon -t test_watch_t $basedir/test_fanotify -r >>>>>> $basedir/watch_me 2>&1"); >>>>>> +ok($exit_val); # this should fail >>>>>> + >>>>>> +# Should NOT be able to set read based inotify watch >>>>>> +$exit_val = system( >>>>>> + "runcon -t test_watch_t $basedir/test_inotify -r >>>>>> $basedir/watch_me 2>&1"); >>>>>> +ok($exit_val); # this should fail >>>>>> + >>>>>> +## TEST PERM WATCH >>>>>> +# Should be able to set permission based fanotify watch >>>>>> +$exit_val = system( >>>>>> +"runcon -t test_perm_watch_t $basedir/test_fanotify -p >>>>>> $basedir/watch_me 2>&1" >>>>>> +); >>>>>> +ok( $exit_val, 0 ); >>>>>> + >>>>>> +# Should NOT be able to set watch of accesses >>>>>> +$exit_val = system( >>>>>> +"runcon -t test_perm_watch_t $basedir/test_fanotify -r >>>>>> $basedir/watch_me 2>&1" >>>>>> +); >>>>>> +ok($exit_val); # this should fail >>>>>> + >>>>>> +## TEST READ NO PERM WATCH PERMSISSIONS >>>>>> +# Should NOT be able to set read and perm watch >>>>>> +$exit_val = system( >>>>>> +"runcon -t test_read_watch_t $basedir/test_fanotify -p -r >>>>>> $basedir/watch_me 2>&1" >>>>>> +); >>>>>> +ok($exit_val); # should fail >>>>>> + >>>>>> +# Should be able to set read inotify watch >>>>>> +$exit_val = system( >>>>>> +"runcon -t test_read_watch_t $basedir/test_inotify -r >>>>>> $basedir/watch_me 2>&1" >>>>>> +); >>>>>> +ok( $exit_val, 0 ); >>>>>> + >>>>>> +## TEST READ WITH PERM WATCH PERMSISSIONS >>>>>> +# Should be able to set read and perm watch >>>>>> +$exit_val = system( >>>>>> +"runcon -t test_perm_read_watch_t $basedir/test_fanotify -p -r >>>>>> $basedir/watch_me 2>&1" >>>>>> +); >>>>>> +ok( $exit_val, 0 ); >>>>>> + >>>>>> +## TEST NO WATCH PERMSISSIONS >>>>>> +# Should NOT be able to set inotify watch >>>>>> +$exit_val = system( >>>>>> + "runcon -t test_no_watch_t $basedir/test_inotify >>>>>> $basedir/watch_me 2>&1"); >>>>>> +ok($exit_val); # this should fail >>>>>> + >>>>>> +# Should NOT be able to set any fanotify watch >>>>>> +$exit_val = system( >>>>>> + "runcon -t test_no_watch_t $basedir/test_fanotify >>>>>> $basedir/watch_me 2>&1"); >>>>>> +ok($exit_val); # this should fail >>>>>> + >>>>>> +## TEST READ ONLY >>>>>> +# Should NOT be able to get read-write descriptor >>>>>> +$exit_val = system( >>>>>> + "runcon -t test_rdonly_t $basedir/test_fanotify -l >>>>>> $basedir/watch_me 2>&1"); >>>>>> +ok($exit_val); # this should fail >>>>>> + >>>>>> +# Should be able to get read-write descriptor >>>>>> +$exit_val = system( >>>>>> + "runcon -t test_watch_t $basedir/test_fanotify -l >>>>>> $basedir/watch_me 2>&1"); >>>>>> +ok( $exit_val, 0 ); >>>>>> + >>>>>> +# Clean up test file >>>>>> +system("rm -f $basedir/watch_me"); >>>>>> diff --git a/tests/notify/test_fanotify.c >>>>>> b/tests/notify/test_fanotify.c >>>>>> new file mode 100644 >>>>>> index 0000000..fff773f >>>>>> --- /dev/null >>>>>> +++ b/tests/notify/test_fanotify.c >>>>>> @@ -0,0 +1,105 @@ >>>>>> +#define _GNU_SOURCE 1 >>>>>> + >>>>>> +#include <stdio.h> >>>>>> +#include <stdlib.h> >>>>>> + >>>>>> +#include <getopt.h> >>>>>> + >>>>>> +#include <fcntl.h> >>>>>> +#include <poll.h> >>>>>> +#include <sys/fanotify.h> >>>>>> +#include <unistd.h> >>>>>> + >>>>>> +void printUsage() >>>>>> +{ >>>>>> + fprintf(stderr, "Usage: test_fanotify [-p] [-r] [-l] >>>>>> file_name\n"); >>>>>> + exit(1); >>>>>> +} >>>>>> + >>>>>> +int main(int argc, char *argv[]) >>>>>> +{ >>>>>> + if (argc < 2) { >>>>>> + printUsage(); >>>>>> + } >>>>>> + >>>>>> + int fd, ret, arg; >>>>>> + int mask = FAN_OPEN; // default mask >>>>>> + int listening = 0; >>>>>> + >>>>>> + // the -p flag will test for watch_with_perm >>>>>> + // the mask used at mark will contain FAN_OPEN_PERM >>>>>> + // >>>>>> + // the -r flag will test for watching accesses to files for >>>>>> reads >>>>>> + // the mask will contain FAN_ACCESS >>>>>> + while ((arg = getopt(argc, argv, "prl")) != -1) { >>>>>> + switch (arg) { >>>>>> + case 'p': >>>>>> + mask |= FAN_OPEN_PERM; >>>>>> + break; >>>>>> + case 'r': >>>>>> + mask |= FAN_ACCESS; >>>>>> + break; >>>>>> + case 'l': >>>>>> + listening = 1; >>>>>> + break; >>>>>> + default: >>>>>> + printUsage(); >>>>>> + } >>>>>> + } >>>>>> + >>>>>> + // get file descriptor for new fanotify event queue >>>>>> + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); >>>>>> + if (fd < 0) { >>>>>> + perror("fanotify_init:bad file descriptor"); >>>>>> + exit(1); >>>>>> + } >>>>>> + >>>>>> + // mark a filesystem object and add mark to event queue >>>>>> + // get notifications on file opens, accesses, and closes >>>>>> + // use current working directory as base dir >>>>>> + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, AT_FDCWD, >>>>>> argv[optind]); >>>>>> + >>>>>> + if (ret < 0) { >>>>>> + perror("test_fanotify:watch denied"); >>>>>> + exit(1); >>>>>> + } >>>>>> + >>>>>> + // logic to actually listen for an event if the -l flag is >>>>>> passed >>>>>> + // this is used to test if an app with read-only access can >>>>>> get a read/write >>>>>> + // handle to the watched file >>>>>> + if (listening) { >>>>>> + if (fork() == 0) { // fork a child process to cause an >>>>>> event on the file >>>>>> + FILE *f; >>>>>> + >>>>>> + f = fopen(argv[optind], "r"); // open file for reading >>>>>> + fgetc(f); // read char from file >>>>>> + >>>>>> + fclose(f); >>>>>> + } else { // logic to watch for events and try to access >>>>>> file read/write >>>>>> + struct pollfd fds; >>>>>> + fds.fd = fd; >>>>>> + fds.events = POLLIN; >>>>>> + >>>>>> + while (listening) { >>>>>> + int polled = poll(&fds, 1, 1); >>>>>> + if (polled > 0) { >>>>>> + if (fds.revents & POLLIN) { >>>>>> + struct fanotify_event_metadata buff[200]; >>>>>> + >>>>>> + size_t len = read(fd, (void *)&buff, >>>>>> sizeof(buff)); >>>>>> + if (len == -1) { >>>>>> + perror("test_fanotify:can't open file"); >>>>>> + exit(1); >>>>>> + } else { >>>>>> + listening = 0; >>>>>> + break; >>>>>> + } >>>>>> + } >>>>>> + } else if (polled == -1) { >>>>>> + listening = 0; >>>>>> + } >>>>>> + } >>>>>> + } >>>>>> + } >>>>>> + exit(0); >>>>>> +} >>>>>> diff --git a/tests/notify/test_inotify.c >>>>>> b/tests/notify/test_inotify.c >>>>>> new file mode 100644 >>>>>> index 0000000..17c3565 >>>>>> --- /dev/null >>>>>> +++ b/tests/notify/test_inotify.c >>>>>> @@ -0,0 +1,43 @@ >>>>>> +#include <stdio.h> >>>>>> +#include <stdlib.h> >>>>>> +#include <sys/inotify.h> >>>>>> +#include <getopt.h> >>>>>> + >>>>>> +int main(int argc, char *argv[]) >>>>>> +{ >>>>>> + if (argc < 2) { >>>>>> + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); >>>>>> + exit(1); >>>>>> + } >>>>>> + >>>>>> + int fd, wd, arg; >>>>>> + int mask = IN_MODIFY; >>>>>> + >>>>>> + while ((arg = getopt(argc, argv, "pr")) != -1) { >>>>>> + switch (arg) { >>>>>> + case 'r': >>>>>> + mask |= IN_ACCESS; >>>>>> + break; >>>>>> + default: >>>>>> + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); >>>>>> + exit(1); >>>>>> + } >>>>>> + } >>>>>> + >>>>>> + // get new file descriptor for inotify access >>>>>> + fd = inotify_init(); >>>>>> + if (fd < 0) { >>>>>> + perror("inotify_init:bad file descriptor"); >>>>>> + exit(1); >>>>>> + } >>>>>> + >>>>>> + // set watch on file and get watch descriptor for accessing >>>>>> events on it >>>>>> + wd = inotify_add_watch(fd, argv[optind], mask); >>>>>> + >>>>>> + if (wd < 0) { >>>>>> + perror("test_inotify:watch denied"); >>>>>> + exit(1); >>>>>> + } >>>>>> + >>>>>> + exit(0); >>>>>> +} >>>>>> -- >>>>>> 2.21.0 >>>>>> >>>>> >>>> >>> >> >
On 9/10/19 10:59 AM, Stephen Smalley wrote: > On 9/10/19 10:54 AM, Stephen Smalley wrote: >> On 9/10/19 10:40 AM, Stephen Smalley wrote: >>> On 9/10/19 10:15 AM, Dominick Grift wrote: >>>> On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: >>>>> On 9/10/19 1:59 AM, Dominick Grift wrote: >>>>>> On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: >>>>>>> Added a suite to test permissions for setting inotify and >>>>>>> fanotify watches >>>>>>> on filesystem objects. Tests watch, watch_with_perm, and >>>>>>> watch_reads permissions. >>>>>> >>>>>> Ive also "tested" the fsnotify patch. And my tests indicate that >>>>>> this might cause issues: >>>>>> >>>>>> I added the access vectors to my policy, but on older systems >>>>>> (debian 10) cron fails to start >>>>>> cron needs the "entrypoint" permission on /etc/crontab but it >>>>>> looks like appending the "watch" access vectors to common-file >>>>>> disrupted the ordering >>>>>> The result is that now i have to allow cron to "watch_read" >>>>>> /etc/crontab even though the neither kernel nor selinux user space >>>>>> are aware of the fsnotify access vectors >>>>>> It seems the cron selinux code got confused and now thinks >>>>>> watch_read is entrypoint (its using selinux code to determine >>>>>> whether it can manually transition to cronjob domains on crontabs) >>>>>> >>>>>> I am hoping this issue with resolve itself on systems with kernels >>>>>> and user spaces that suppose fsnotify. >>>>>> However unless i am overlooking something this is still likely to >>>>>> disrupt compatibility >>>>> >>>>> So, IIUC, the issue is that: >>>>> a) older cron was directly using the fixed FILE__ENTRYPOINT >>>>> definition from >>>>> libselinux in a security_compute_av() call rather than dynamically >>>>> looking >>>>> up entrypoint permission, >>>>> b) the value of the file entrypoint permission in policy has >>>>> changed because >>>>> you updated your policy and chose to place the watch* permissions >>>>> in the >>>>> common file definition to match the kernel. >>>>> >>>>> Note that you could have instead sprinkled copies of the watch* >>>>> permissions >>>>> across all of the individual file/dir/*_file classes and placed >>>>> them at the >>>>> end of the classes if you wanted to avoid this compatibility issue. >>>>> The >>>>> policy and kernel definitions no longer need to be identical; the >>>>> kernel >>>>> will dynamically map between them for its own permission checks. >>>>> >>>>> Also, this should have already been broken for you when map >>>>> permission was >>>>> added, which would have shown up as execute_no_trans being checked >>>>> instead >>>>> of entrypoint. This was already filed as a bug on cron in debian >>>>> here: >>>>> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 >>>>> >>>>> So, wrt compatibility, IIUC: >>>>> - the kernel change does not break compatibility for old policy + old >>>>> userspace, >>>>> - new policy can choose to add the new permissions in a >>>>> backward-compatible >>>>> manner if desired, although refpolicy has already chosen not to do >>>>> this for >>>>> map permission, >>>>> - the offending code in cron produces build warnings that were >>>>> introduced in >>>>> 2014 in libselinux to update their code to use the dynamic class/perm >>>>> mapping support, which would resolve the issue. >>>> >>>> this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): >>>> https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d >>>> >>>> >>>> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x --common >>>> common_file >>>> >>>> Commons: 1 >>>> common common_file >>>> { >>>> append >>>> lock >>>> mounton >>>> unlink >>>> read >>>> create >>>> quotaon >>>> execute >>>> setattr >>>> map >>>> relabelto >>>> rename >>>> link >>>> ioctl >>>> getattr >>>> relabelfrom >>>> } >>>> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile >>>> >>>> Classes: 1 >>>> class file >>>> inherits common_file >>>> { >>>> execmod >>>> watch >>>> write >>>> watch_reads >>>> execute_no_trans >>>> watch_mount >>>> watch_with_perm >>>> open >>>> watch_sb >>>> audit_access >>>> entrypoint >>>> } >>> >>> If you want to preserve compatibility with userspace using fixed >>> definitions of FILE__ENTRYPOINT, then you have to insert any new file >>> permissions after the current entrypoint permission in the class >>> file. So watch and friends have to go after it, not before it. >>> >>> Also, since the kernel always uses FILE__WATCH* in the check code >>> rather than distinguishing by class, the watch* permissions need to >>> be at the same offset in all of the file classes. The same is true >>> of the other file permissions. It looks like you may have other >>> permissions out of sync across the file classes e.g. execmod, open, >>> audit_access, that need to be aligned or the kernel could check the >>> wrong permission. >> >> Sorry, the last para isn't correct - it should get mapped correctly >> per class. But you do need to add the permissions after entrypoint in >> the file class to avoid displacing its value. > > Also, it looks like your file class permission order differs in other > incompatible ways. If you want it to be compatible with the deprecated > libselinux headers, the requisite order would be: > class file > inherits common_file > { > execute_no_trans > entrypoint > execmod > open > audit_access > map Sorry, insert watch* permissions here. > } > >> >>> >>>> >>>>> >>>>>> >>>>>>> >>>>>>> Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> >>>>>>> --- >>>>>>> policy/Makefile | 4 ++ >>>>>>> policy/test_notify.te | 74 ++++++++++++++++++++++++ >>>>>>> tests/Makefile | 4 ++ >>>>>>> tests/notify/Makefile | 5 ++ >>>>>>> tests/notify/test | 101 >>>>>>> +++++++++++++++++++++++++++++++++ >>>>>>> tests/notify/test_fanotify.c | 105 >>>>>>> +++++++++++++++++++++++++++++++++++ >>>>>>> tests/notify/test_inotify.c | 43 ++++++++++++++ >>>>>>> 7 files changed, 336 insertions(+) >>>>>>> create mode 100644 policy/test_notify.te >>>>>>> create mode 100644 tests/notify/Makefile >>>>>>> create mode 100755 tests/notify/test >>>>>>> create mode 100644 tests/notify/test_fanotify.c >>>>>>> create mode 100644 tests/notify/test_inotify.c >>>>>>> >>>>>>> diff --git a/policy/Makefile b/policy/Makefile >>>>>>> index 305b572..65f88c5 100644 >>>>>>> --- a/policy/Makefile >>>>>>> +++ b/policy/Makefile >>>>>>> @@ -71,6 +71,10 @@ ifeq ($(shell grep -q >>>>>>> corenet_sctp_bind_all_nodes $(POLDEV)/include/kernel/coren >>>>>>> TARGETS += test_sctp.te >>>>>>> endif >>>>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>>>> $(POLDEV)/include/support/all_perms.spt && echo true),true) >>>>>>> +TARGETS+=test_notify.te >>>>>>> +endif >>>>>>> + >>>>>>> ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) >>>>>>> TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te, >>>>>>> $(TARGETS)) >>>>>>> endif >>>>>>> diff --git a/policy/test_notify.te b/policy/test_notify.te >>>>>>> new file mode 100644 >>>>>>> index 0000000..8ba6f1a >>>>>>> --- /dev/null >>>>>>> +++ b/policy/test_notify.te >>>>>>> @@ -0,0 +1,74 @@ >>>>>>> +#################################################### >>>>>>> +# Policy for testing inoftify and fanotify watches # >>>>>>> +#################################################### >>>>>>> + >>>>>>> +attribute test_notify_domain; >>>>>>> + >>>>>>> +# Type for the file on which we want to set a watch >>>>>>> +type test_notify_file_t; >>>>>>> +files_type(test_notify_file_t); >>>>>>> + >>>>>>> +# Domain for the process which CAN set a non-permission watch >>>>>>> +type test_watch_t; >>>>>>> +domain_type(test_watch_t); >>>>>>> +unconfined_runs_test(test_watch_t); >>>>>>> + >>>>>>> +typeattribute test_watch_t test_notify_domain; >>>>>>> +typeattribute test_watch_t testdomain; >>>>>>> + >>>>>>> +allow test_notify_domain self:capability sys_admin; >>>>>>> + >>>>>>> +allow test_watch_t test_notify_file_t:file { read write open >>>>>>> watch }; >>>>>>> + >>>>>>> +# Domain for the process which CAN set a NON-access watch on a file >>>>>>> +type test_perm_watch_t; >>>>>>> +domain_type(test_perm_watch_t); >>>>>>> +unconfined_runs_test(test_perm_watch_t); >>>>>>> + >>>>>>> +typeattribute test_perm_watch_t test_notify_domain; >>>>>>> +typeattribute test_perm_watch_t testdomain; >>>>>>> + >>>>>>> +allow test_perm_watch_t test_notify_file_t:file { read write >>>>>>> open watch watch_with_perm }; >>>>>>> + >>>>>>> +# Domain which CAN set a NON-perm watch which MAY read accesses >>>>>>> +type test_read_watch_t; >>>>>>> +domain_type(test_read_watch_t); >>>>>>> +unconfined_runs_test(test_read_watch_t); >>>>>>> + >>>>>>> +typeattribute test_read_watch_t test_notify_domain; >>>>>>> +typeattribute test_read_watch_t testdomain; >>>>>>> + >>>>>>> +allow test_read_watch_t test_notify_file_t:file { read write >>>>>>> open watch watch_reads }; >>>>>>> + >>>>>>> +# Domain which CAN set any watch which CAN read accesses >>>>>>> +type test_perm_read_watch_t; >>>>>>> +domain_type(test_perm_read_watch_t); >>>>>>> +unconfined_runs_test(test_perm_read_watch_t); >>>>>>> + >>>>>>> +typeattribute test_perm_read_watch_t test_notify_domain; >>>>>>> +typeattribute test_perm_read_watch_t testdomain; >>>>>>> + >>>>>>> +allow test_perm_read_watch_t test_notify_file_t:file { read >>>>>>> write open watch watch_with_perm watch_reads }; >>>>>>> + >>>>>>> +# Domain which CANNOT set any watches >>>>>>> +type test_no_watch_t; >>>>>>> +domain_type(test_no_watch_t); >>>>>>> +unconfined_runs_test(test_no_watch_t); >>>>>>> + >>>>>>> +typeattribute test_no_watch_t test_notify_domain; >>>>>>> +typeattribute test_no_watch_t testdomain; >>>>>>> + >>>>>>> +allow test_no_watch_t test_notify_file_t:file { read write open }; >>>>>>> + >>>>>>> +# Domain which has no write access but can watch >>>>>>> +type test_rdonly_t; >>>>>>> +domain_type(test_rdonly_t); >>>>>>> +unconfined_runs_test(test_rdonly_t); >>>>>>> + >>>>>>> +typeattribute test_rdonly_t test_notify_domain; >>>>>>> +typeattribute test_rdonly_t testdomain; >>>>>>> + >>>>>>> +allow test_rdonly_t test_notify_file_t:file { read open watch }; >>>>>>> + >>>>>>> +miscfiles_domain_entry_test_files(test_notify_domain); >>>>>>> +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); >>>>>>> diff --git a/tests/Makefile b/tests/Makefile >>>>>>> index 63aa325..b99c96e 100644 >>>>>>> --- a/tests/Makefile >>>>>>> +++ b/tests/Makefile >>>>>>> @@ -50,6 +50,10 @@ ifeq ($(shell grep >>>>>>> "^SELINUX_INFINIBAND_PKEY_TEST=" infiniband_pkey/ibpkey_test. >>>>>>> SUBDIRS += infiniband_pkey >>>>>>> endif >>>>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>>>> $(POLDEV)/include/support/all_perms.spt && echo true),true) >>>>>>> +SUBDIRS+=notify >>>>>>> +endif >>>>>>> + >>>>>>> ifeq ($(DISTRO),RHEL4) >>>>>>> SUBDIRS:=$(filter-out bounds dyntrace dyntrans inet_socket >>>>>>> mmap nnp_nosuid overlay unix_socket, $(SUBDIRS)) >>>>>>> endif >>>>>>> diff --git a/tests/notify/Makefile b/tests/notify/Makefile >>>>>>> new file mode 100644 >>>>>>> index 0000000..78c4b3b >>>>>>> --- /dev/null >>>>>>> +++ b/tests/notify/Makefile >>>>>>> @@ -0,0 +1,5 @@ >>>>>>> +TARGETS=test_inotify test_fanotify >>>>>>> + >>>>>>> +all: $(TARGETS) >>>>>>> +clean: >>>>>>> + rm -f $(TARGETS) >>>>>>> diff --git a/tests/notify/test b/tests/notify/test >>>>>>> new file mode 100755 >>>>>>> index 0000000..21f03de >>>>>>> --- /dev/null >>>>>>> +++ b/tests/notify/test >>>>>>> @@ -0,0 +1,101 @@ >>>>>>> +#!/usr/bin/perl >>>>>>> + >>>>>>> +use Test; >>>>>>> +BEGIN { plan tests => 14 } # number of tests to run >>>>>>> + >>>>>>> +# help the test script locate itself >>>>>>> +$basedir = $0; >>>>>>> +$basedir =~ s|(.*)/[^/]*|$1|; >>>>>>> + >>>>>>> +# Get rid of a testfile from last run if it's there (just in case) >>>>>>> +system("rm -f $basedir/watch_me"); >>>>>>> + >>>>>>> +# Create a new test file >>>>>>> +system("touch $basedir/watch_me"); >>>>>>> +system("chcon -t test_notify_file_t $basedir/watch_me"); >>>>>>> + >>>>>>> +## TESTS >>>>>>> + >>>>>>> +## TEST BASIC WATCH PERMISSION >>>>>>> +# Should be able to set inotify watch >>>>>>> +$exit_val = >>>>>>> + system("runcon -t test_watch_t $basedir/test_inotify >>>>>>> $basedir/watch_me 2>&1"); >>>>>>> +ok( $exit_val, 0 ); >>>>>>> + >>>>>>> +# Should be able to set non-permissions based fanotify watch >>>>>>> +$exit_val = system( >>>>>>> + "runcon -t test_watch_t $basedir/test_fanotify >>>>>>> $basedir/watch_me 2>&1"); >>>>>>> +ok( $exit_val, 0 ); >>>>>>> + >>>>>>> +# Should NOT be able to set permission based fanotify watch >>>>>>> +$exit_val = system( >>>>>>> + "runcon -t test_watch_t $basedir/test_fanotify -p >>>>>>> $basedir/watch_me 2>&1"); >>>>>>> +ok($exit_val); # this should fail >>>>>>> + >>>>>>> +# Should NOT be able to set read based fanotify watch >>>>>>> +$exit_val = system( >>>>>>> + "runcon -t test_watch_t $basedir/test_fanotify -r >>>>>>> $basedir/watch_me 2>&1"); >>>>>>> +ok($exit_val); # this should fail >>>>>>> + >>>>>>> +# Should NOT be able to set read based inotify watch >>>>>>> +$exit_val = system( >>>>>>> + "runcon -t test_watch_t $basedir/test_inotify -r >>>>>>> $basedir/watch_me 2>&1"); >>>>>>> +ok($exit_val); # this should fail >>>>>>> + >>>>>>> +## TEST PERM WATCH >>>>>>> +# Should be able to set permission based fanotify watch >>>>>>> +$exit_val = system( >>>>>>> +"runcon -t test_perm_watch_t $basedir/test_fanotify -p >>>>>>> $basedir/watch_me 2>&1" >>>>>>> +); >>>>>>> +ok( $exit_val, 0 ); >>>>>>> + >>>>>>> +# Should NOT be able to set watch of accesses >>>>>>> +$exit_val = system( >>>>>>> +"runcon -t test_perm_watch_t $basedir/test_fanotify -r >>>>>>> $basedir/watch_me 2>&1" >>>>>>> +); >>>>>>> +ok($exit_val); # this should fail >>>>>>> + >>>>>>> +## TEST READ NO PERM WATCH PERMSISSIONS >>>>>>> +# Should NOT be able to set read and perm watch >>>>>>> +$exit_val = system( >>>>>>> +"runcon -t test_read_watch_t $basedir/test_fanotify -p -r >>>>>>> $basedir/watch_me 2>&1" >>>>>>> +); >>>>>>> +ok($exit_val); # should fail >>>>>>> + >>>>>>> +# Should be able to set read inotify watch >>>>>>> +$exit_val = system( >>>>>>> +"runcon -t test_read_watch_t $basedir/test_inotify -r >>>>>>> $basedir/watch_me 2>&1" >>>>>>> +); >>>>>>> +ok( $exit_val, 0 ); >>>>>>> + >>>>>>> +## TEST READ WITH PERM WATCH PERMSISSIONS >>>>>>> +# Should be able to set read and perm watch >>>>>>> +$exit_val = system( >>>>>>> +"runcon -t test_perm_read_watch_t $basedir/test_fanotify -p -r >>>>>>> $basedir/watch_me 2>&1" >>>>>>> +); >>>>>>> +ok( $exit_val, 0 ); >>>>>>> + >>>>>>> +## TEST NO WATCH PERMSISSIONS >>>>>>> +# Should NOT be able to set inotify watch >>>>>>> +$exit_val = system( >>>>>>> + "runcon -t test_no_watch_t $basedir/test_inotify >>>>>>> $basedir/watch_me 2>&1"); >>>>>>> +ok($exit_val); # this should fail >>>>>>> + >>>>>>> +# Should NOT be able to set any fanotify watch >>>>>>> +$exit_val = system( >>>>>>> + "runcon -t test_no_watch_t $basedir/test_fanotify >>>>>>> $basedir/watch_me 2>&1"); >>>>>>> +ok($exit_val); # this should fail >>>>>>> + >>>>>>> +## TEST READ ONLY >>>>>>> +# Should NOT be able to get read-write descriptor >>>>>>> +$exit_val = system( >>>>>>> + "runcon -t test_rdonly_t $basedir/test_fanotify -l >>>>>>> $basedir/watch_me 2>&1"); >>>>>>> +ok($exit_val); # this should fail >>>>>>> + >>>>>>> +# Should be able to get read-write descriptor >>>>>>> +$exit_val = system( >>>>>>> + "runcon -t test_watch_t $basedir/test_fanotify -l >>>>>>> $basedir/watch_me 2>&1"); >>>>>>> +ok( $exit_val, 0 ); >>>>>>> + >>>>>>> +# Clean up test file >>>>>>> +system("rm -f $basedir/watch_me"); >>>>>>> diff --git a/tests/notify/test_fanotify.c >>>>>>> b/tests/notify/test_fanotify.c >>>>>>> new file mode 100644 >>>>>>> index 0000000..fff773f >>>>>>> --- /dev/null >>>>>>> +++ b/tests/notify/test_fanotify.c >>>>>>> @@ -0,0 +1,105 @@ >>>>>>> +#define _GNU_SOURCE 1 >>>>>>> + >>>>>>> +#include <stdio.h> >>>>>>> +#include <stdlib.h> >>>>>>> + >>>>>>> +#include <getopt.h> >>>>>>> + >>>>>>> +#include <fcntl.h> >>>>>>> +#include <poll.h> >>>>>>> +#include <sys/fanotify.h> >>>>>>> +#include <unistd.h> >>>>>>> + >>>>>>> +void printUsage() >>>>>>> +{ >>>>>>> + fprintf(stderr, "Usage: test_fanotify [-p] [-r] [-l] >>>>>>> file_name\n"); >>>>>>> + exit(1); >>>>>>> +} >>>>>>> + >>>>>>> +int main(int argc, char *argv[]) >>>>>>> +{ >>>>>>> + if (argc < 2) { >>>>>>> + printUsage(); >>>>>>> + } >>>>>>> + >>>>>>> + int fd, ret, arg; >>>>>>> + int mask = FAN_OPEN; // default mask >>>>>>> + int listening = 0; >>>>>>> + >>>>>>> + // the -p flag will test for watch_with_perm >>>>>>> + // the mask used at mark will contain FAN_OPEN_PERM >>>>>>> + // >>>>>>> + // the -r flag will test for watching accesses to files for >>>>>>> reads >>>>>>> + // the mask will contain FAN_ACCESS >>>>>>> + while ((arg = getopt(argc, argv, "prl")) != -1) { >>>>>>> + switch (arg) { >>>>>>> + case 'p': >>>>>>> + mask |= FAN_OPEN_PERM; >>>>>>> + break; >>>>>>> + case 'r': >>>>>>> + mask |= FAN_ACCESS; >>>>>>> + break; >>>>>>> + case 'l': >>>>>>> + listening = 1; >>>>>>> + break; >>>>>>> + default: >>>>>>> + printUsage(); >>>>>>> + } >>>>>>> + } >>>>>>> + >>>>>>> + // get file descriptor for new fanotify event queue >>>>>>> + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); >>>>>>> + if (fd < 0) { >>>>>>> + perror("fanotify_init:bad file descriptor"); >>>>>>> + exit(1); >>>>>>> + } >>>>>>> + >>>>>>> + // mark a filesystem object and add mark to event queue >>>>>>> + // get notifications on file opens, accesses, and closes >>>>>>> + // use current working directory as base dir >>>>>>> + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, AT_FDCWD, >>>>>>> argv[optind]); >>>>>>> + >>>>>>> + if (ret < 0) { >>>>>>> + perror("test_fanotify:watch denied"); >>>>>>> + exit(1); >>>>>>> + } >>>>>>> + >>>>>>> + // logic to actually listen for an event if the -l flag is >>>>>>> passed >>>>>>> + // this is used to test if an app with read-only access can >>>>>>> get a read/write >>>>>>> + // handle to the watched file >>>>>>> + if (listening) { >>>>>>> + if (fork() == 0) { // fork a child process to cause an >>>>>>> event on the file >>>>>>> + FILE *f; >>>>>>> + >>>>>>> + f = fopen(argv[optind], "r"); // open file for reading >>>>>>> + fgetc(f); // read char from file >>>>>>> + >>>>>>> + fclose(f); >>>>>>> + } else { // logic to watch for events and try to access >>>>>>> file read/write >>>>>>> + struct pollfd fds; >>>>>>> + fds.fd = fd; >>>>>>> + fds.events = POLLIN; >>>>>>> + >>>>>>> + while (listening) { >>>>>>> + int polled = poll(&fds, 1, 1); >>>>>>> + if (polled > 0) { >>>>>>> + if (fds.revents & POLLIN) { >>>>>>> + struct fanotify_event_metadata buff[200]; >>>>>>> + >>>>>>> + size_t len = read(fd, (void *)&buff, >>>>>>> sizeof(buff)); >>>>>>> + if (len == -1) { >>>>>>> + perror("test_fanotify:can't open >>>>>>> file"); >>>>>>> + exit(1); >>>>>>> + } else { >>>>>>> + listening = 0; >>>>>>> + break; >>>>>>> + } >>>>>>> + } >>>>>>> + } else if (polled == -1) { >>>>>>> + listening = 0; >>>>>>> + } >>>>>>> + } >>>>>>> + } >>>>>>> + } >>>>>>> + exit(0); >>>>>>> +} >>>>>>> diff --git a/tests/notify/test_inotify.c >>>>>>> b/tests/notify/test_inotify.c >>>>>>> new file mode 100644 >>>>>>> index 0000000..17c3565 >>>>>>> --- /dev/null >>>>>>> +++ b/tests/notify/test_inotify.c >>>>>>> @@ -0,0 +1,43 @@ >>>>>>> +#include <stdio.h> >>>>>>> +#include <stdlib.h> >>>>>>> +#include <sys/inotify.h> >>>>>>> +#include <getopt.h> >>>>>>> + >>>>>>> +int main(int argc, char *argv[]) >>>>>>> +{ >>>>>>> + if (argc < 2) { >>>>>>> + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); >>>>>>> + exit(1); >>>>>>> + } >>>>>>> + >>>>>>> + int fd, wd, arg; >>>>>>> + int mask = IN_MODIFY; >>>>>>> + >>>>>>> + while ((arg = getopt(argc, argv, "pr")) != -1) { >>>>>>> + switch (arg) { >>>>>>> + case 'r': >>>>>>> + mask |= IN_ACCESS; >>>>>>> + break; >>>>>>> + default: >>>>>>> + fprintf(stderr, "Usage: test_inotify [-r] >>>>>>> file_name\n"); >>>>>>> + exit(1); >>>>>>> + } >>>>>>> + } >>>>>>> + >>>>>>> + // get new file descriptor for inotify access >>>>>>> + fd = inotify_init(); >>>>>>> + if (fd < 0) { >>>>>>> + perror("inotify_init:bad file descriptor"); >>>>>>> + exit(1); >>>>>>> + } >>>>>>> + >>>>>>> + // set watch on file and get watch descriptor for accessing >>>>>>> events on it >>>>>>> + wd = inotify_add_watch(fd, argv[optind], mask); >>>>>>> + >>>>>>> + if (wd < 0) { >>>>>>> + perror("test_inotify:watch denied"); >>>>>>> + exit(1); >>>>>>> + } >>>>>>> + >>>>>>> + exit(0); >>>>>>> +} >>>>>>> -- >>>>>>> 2.21.0 >>>>>>> >>>>>> >>>>> >>>> >>> >> >
On Tue, Sep 10, 2019 at 11:02:16AM -0400, Stephen Smalley wrote: > On 9/10/19 10:59 AM, Stephen Smalley wrote: > > On 9/10/19 10:54 AM, Stephen Smalley wrote: > > > On 9/10/19 10:40 AM, Stephen Smalley wrote: > > > > On 9/10/19 10:15 AM, Dominick Grift wrote: > > > > > On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: > > > > > > On 9/10/19 1:59 AM, Dominick Grift wrote: > > > > > > > On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: > > > > > > > > Added a suite to test permissions for setting > > > > > > > > inotify and fanotify watches > > > > > > > > on filesystem objects. Tests watch, > > > > > > > > watch_with_perm, and watch_reads permissions. > > > > > > > > > > > > > > Ive also "tested" the fsnotify patch. And my tests > > > > > > > indicate that this might cause issues: > > > > > > > > > > > > > > I added the access vectors to my policy, but on > > > > > > > older systems (debian 10) cron fails to start > > > > > > > cron needs the "entrypoint" permission on > > > > > > > /etc/crontab but it looks like appending the "watch" > > > > > > > access vectors to common-file disrupted the ordering > > > > > > > The result is that now i have to allow cron to > > > > > > > "watch_read" /etc/crontab even though the neither > > > > > > > kernel nor selinux user space are aware of the > > > > > > > fsnotify access vectors > > > > > > > It seems the cron selinux code got confused and now > > > > > > > thinks watch_read is entrypoint (its using selinux > > > > > > > code to determine whether it can manually transition > > > > > > > to cronjob domains on crontabs) > > > > > > > > > > > > > > I am hoping this issue with resolve itself on > > > > > > > systems with kernels and user spaces that suppose > > > > > > > fsnotify. > > > > > > > However unless i am overlooking something this is > > > > > > > still likely to disrupt compatibility > > > > > > > > > > > > So, IIUC, the issue is that: > > > > > > a) older cron was directly using the fixed > > > > > > FILE__ENTRYPOINT definition from > > > > > > libselinux in a security_compute_av() call rather than > > > > > > dynamically looking > > > > > > up entrypoint permission, > > > > > > b) the value of the file entrypoint permission in policy > > > > > > has changed because > > > > > > you updated your policy and chose to place the watch* > > > > > > permissions in the > > > > > > common file definition to match the kernel. > > > > > > > > > > > > Note that you could have instead sprinkled copies of the > > > > > > watch* permissions > > > > > > across all of the individual file/dir/*_file classes and > > > > > > placed them at the > > > > > > end of the classes if you wanted to avoid this > > > > > > compatibility issue. The > > > > > > policy and kernel definitions no longer need to be > > > > > > identical; the kernel > > > > > > will dynamically map between them for its own permission checks. > > > > > > > > > > > > Also, this should have already been broken for you when > > > > > > map permission was > > > > > > added, which would have shown up as execute_no_trans > > > > > > being checked instead > > > > > > of entrypoint. This was already filed as a bug on cron > > > > > > in debian here: > > > > > > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 > > > > > > > > > > > > So, wrt compatibility, IIUC: > > > > > > - the kernel change does not break compatibility for old policy + old > > > > > > userspace, > > > > > > - new policy can choose to add the new permissions in a > > > > > > backward-compatible > > > > > > manner if desired, although refpolicy has already chosen > > > > > > not to do this for > > > > > > map permission, > > > > > > - the offending code in cron produces build warnings > > > > > > that were introduced in > > > > > > 2014 in libselinux to update their code to use the dynamic class/perm > > > > > > mapping support, which would resolve the issue. > > > > > > > > > > this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d > > > > > > > > > > > > > > > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x > > > > > --common common_file > > > > > > > > > > Commons: 1 > > > > > common common_file > > > > > { > > > > > append > > > > > lock > > > > > mounton > > > > > unlink > > > > > read > > > > > create > > > > > quotaon > > > > > execute > > > > > setattr > > > > > map > > > > > relabelto > > > > > rename > > > > > link > > > > > ioctl > > > > > getattr > > > > > relabelfrom > > > > > } > > > > > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile > > > > > > > > > > Classes: 1 > > > > > class file > > > > > inherits common_file > > > > > { > > > > > execmod > > > > > watch > > > > > write > > > > > watch_reads > > > > > execute_no_trans > > > > > watch_mount > > > > > watch_with_perm > > > > > open > > > > > watch_sb > > > > > audit_access > > > > > entrypoint > > > > > } > > > > > > > > If you want to preserve compatibility with userspace using fixed > > > > definitions of FILE__ENTRYPOINT, then you have to insert any new > > > > file permissions after the current entrypoint permission in the > > > > class file. So watch and friends have to go after it, not before > > > > it. > > > > > > > > Also, since the kernel always uses FILE__WATCH* in the check > > > > code rather than distinguishing by class, the watch* permissions > > > > need to be at the same offset in all of the file classes. The > > > > same is true of the other file permissions. It looks like you > > > > may have other permissions out of sync across the file classes > > > > e.g. execmod, open, audit_access, that need to be aligned or the > > > > kernel could check the wrong permission. > > > > > > Sorry, the last para isn't correct - it should get mapped correctly > > > per class. But you do need to add the permissions after entrypoint > > > in the file class to avoid displacing its value. > > > > Also, it looks like your file class permission order differs in other > > incompatible ways. If you want it to be compatible with the deprecated > > libselinux headers, the requisite order would be: > > class file > > inherits common_file > > { > > execute_no_trans > > entrypoint > > execmod > > open > > audit_access > > map > > Sorry, insert watch* permissions here. I applied brute force: the map permission can be part of common_file just fine. the audit_access av (which was clearly introduced after entrypoint can precede entrypoint just fine. The problem is the prescence of the fsnotify access vector in general. Moving them out of common_file and after entrypoint does not make a difference. As soon as I remove the fsnotify av's things start to work. In other words. besides the precensce of the fsnotify access vectors everything (seemingly) is in order Now for me the question remains: will this issue automatically resolve itself as soon as userspace and kernel support the fsnotify av > > > } > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> > > > > > > > > --- > > > > > > > > policy/Makefile | 4 ++ > > > > > > > > policy/test_notify.te | 74 ++++++++++++++++++++++++ > > > > > > > > tests/Makefile | 4 ++ > > > > > > > > tests/notify/Makefile | 5 ++ > > > > > > > > tests/notify/test | 101 > > > > > > > > +++++++++++++++++++++++++++++++++ > > > > > > > > tests/notify/test_fanotify.c | 105 > > > > > > > > +++++++++++++++++++++++++++++++++++ > > > > > > > > tests/notify/test_inotify.c | 43 ++++++++++++++ > > > > > > > > 7 files changed, 336 insertions(+) > > > > > > > > create mode 100644 policy/test_notify.te > > > > > > > > create mode 100644 tests/notify/Makefile > > > > > > > > create mode 100755 tests/notify/test > > > > > > > > create mode 100644 tests/notify/test_fanotify.c > > > > > > > > create mode 100644 tests/notify/test_inotify.c > > > > > > > > > > > > > > > > diff --git a/policy/Makefile b/policy/Makefile > > > > > > > > index 305b572..65f88c5 100644 > > > > > > > > --- a/policy/Makefile > > > > > > > > +++ b/policy/Makefile > > > > > > > > @@ -71,6 +71,10 @@ ifeq ($(shell grep -q > > > > > > > > corenet_sctp_bind_all_nodes > > > > > > > > $(POLDEV)/include/kernel/coren > > > > > > > > TARGETS += test_sctp.te > > > > > > > > endif > > > > > > > > +ifeq ($(shell grep -q all_file_perms.*watch > > > > > > > > $(POLDEV)/include/support/all_perms.spt && echo > > > > > > > > true),true) > > > > > > > > +TARGETS+=test_notify.te > > > > > > > > +endif > > > > > > > > + > > > > > > > > ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) > > > > > > > > TARGETS:=$(filter-out test_overlayfs.te > > > > > > > > test_mqueue.te, $(TARGETS)) > > > > > > > > endif > > > > > > > > diff --git a/policy/test_notify.te b/policy/test_notify.te > > > > > > > > new file mode 100644 > > > > > > > > index 0000000..8ba6f1a > > > > > > > > --- /dev/null > > > > > > > > +++ b/policy/test_notify.te > > > > > > > > @@ -0,0 +1,74 @@ > > > > > > > > +#################################################### > > > > > > > > +# Policy for testing inoftify and fanotify watches # > > > > > > > > +#################################################### > > > > > > > > + > > > > > > > > +attribute test_notify_domain; > > > > > > > > + > > > > > > > > +# Type for the file on which we want to set a watch > > > > > > > > +type test_notify_file_t; > > > > > > > > +files_type(test_notify_file_t); > > > > > > > > + > > > > > > > > +# Domain for the process which CAN set a non-permission watch > > > > > > > > +type test_watch_t; > > > > > > > > +domain_type(test_watch_t); > > > > > > > > +unconfined_runs_test(test_watch_t); > > > > > > > > + > > > > > > > > +typeattribute test_watch_t test_notify_domain; > > > > > > > > +typeattribute test_watch_t testdomain; > > > > > > > > + > > > > > > > > +allow test_notify_domain self:capability sys_admin; > > > > > > > > + > > > > > > > > +allow test_watch_t test_notify_file_t:file { > > > > > > > > read write open watch }; > > > > > > > > + > > > > > > > > +# Domain for the process which CAN set a NON-access watch on a file > > > > > > > > +type test_perm_watch_t; > > > > > > > > +domain_type(test_perm_watch_t); > > > > > > > > +unconfined_runs_test(test_perm_watch_t); > > > > > > > > + > > > > > > > > +typeattribute test_perm_watch_t test_notify_domain; > > > > > > > > +typeattribute test_perm_watch_t testdomain; > > > > > > > > + > > > > > > > > +allow test_perm_watch_t test_notify_file_t:file > > > > > > > > { read write open watch watch_with_perm }; > > > > > > > > + > > > > > > > > +# Domain which CAN set a NON-perm watch which MAY read accesses > > > > > > > > +type test_read_watch_t; > > > > > > > > +domain_type(test_read_watch_t); > > > > > > > > +unconfined_runs_test(test_read_watch_t); > > > > > > > > + > > > > > > > > +typeattribute test_read_watch_t test_notify_domain; > > > > > > > > +typeattribute test_read_watch_t testdomain; > > > > > > > > + > > > > > > > > +allow test_read_watch_t test_notify_file_t:file > > > > > > > > { read write open watch watch_reads }; > > > > > > > > + > > > > > > > > +# Domain which CAN set any watch which CAN read accesses > > > > > > > > +type test_perm_read_watch_t; > > > > > > > > +domain_type(test_perm_read_watch_t); > > > > > > > > +unconfined_runs_test(test_perm_read_watch_t); > > > > > > > > + > > > > > > > > +typeattribute test_perm_read_watch_t test_notify_domain; > > > > > > > > +typeattribute test_perm_read_watch_t testdomain; > > > > > > > > + > > > > > > > > +allow test_perm_read_watch_t > > > > > > > > test_notify_file_t:file { read write open watch > > > > > > > > watch_with_perm watch_reads }; > > > > > > > > + > > > > > > > > +# Domain which CANNOT set any watches > > > > > > > > +type test_no_watch_t; > > > > > > > > +domain_type(test_no_watch_t); > > > > > > > > +unconfined_runs_test(test_no_watch_t); > > > > > > > > + > > > > > > > > +typeattribute test_no_watch_t test_notify_domain; > > > > > > > > +typeattribute test_no_watch_t testdomain; > > > > > > > > + > > > > > > > > +allow test_no_watch_t test_notify_file_t:file { read write open }; > > > > > > > > + > > > > > > > > +# Domain which has no write access but can watch > > > > > > > > +type test_rdonly_t; > > > > > > > > +domain_type(test_rdonly_t); > > > > > > > > +unconfined_runs_test(test_rdonly_t); > > > > > > > > + > > > > > > > > +typeattribute test_rdonly_t test_notify_domain; > > > > > > > > +typeattribute test_rdonly_t testdomain; > > > > > > > > + > > > > > > > > +allow test_rdonly_t test_notify_file_t:file { read open watch }; > > > > > > > > + > > > > > > > > +miscfiles_domain_entry_test_files(test_notify_domain); > > > > > > > > +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); > > > > > > > > diff --git a/tests/Makefile b/tests/Makefile > > > > > > > > index 63aa325..b99c96e 100644 > > > > > > > > --- a/tests/Makefile > > > > > > > > +++ b/tests/Makefile > > > > > > > > @@ -50,6 +50,10 @@ ifeq ($(shell grep > > > > > > > > "^SELINUX_INFINIBAND_PKEY_TEST=" > > > > > > > > infiniband_pkey/ibpkey_test. > > > > > > > > SUBDIRS += infiniband_pkey > > > > > > > > endif > > > > > > > > +ifeq ($(shell grep -q all_file_perms.*watch > > > > > > > > $(POLDEV)/include/support/all_perms.spt && echo > > > > > > > > true),true) > > > > > > > > +SUBDIRS+=notify > > > > > > > > +endif > > > > > > > > + > > > > > > > > ifeq ($(DISTRO),RHEL4) > > > > > > > > SUBDIRS:=$(filter-out bounds dyntrace > > > > > > > > dyntrans inet_socket mmap nnp_nosuid overlay > > > > > > > > unix_socket, $(SUBDIRS)) > > > > > > > > endif > > > > > > > > diff --git a/tests/notify/Makefile b/tests/notify/Makefile > > > > > > > > new file mode 100644 > > > > > > > > index 0000000..78c4b3b > > > > > > > > --- /dev/null > > > > > > > > +++ b/tests/notify/Makefile > > > > > > > > @@ -0,0 +1,5 @@ > > > > > > > > +TARGETS=test_inotify test_fanotify > > > > > > > > + > > > > > > > > +all: $(TARGETS) > > > > > > > > +clean: > > > > > > > > + rm -f $(TARGETS) > > > > > > > > diff --git a/tests/notify/test b/tests/notify/test > > > > > > > > new file mode 100755 > > > > > > > > index 0000000..21f03de > > > > > > > > --- /dev/null > > > > > > > > +++ b/tests/notify/test > > > > > > > > @@ -0,0 +1,101 @@ > > > > > > > > +#!/usr/bin/perl > > > > > > > > + > > > > > > > > +use Test; > > > > > > > > +BEGIN { plan tests => 14 } # number of tests to run > > > > > > > > + > > > > > > > > +# help the test script locate itself > > > > > > > > +$basedir = $0; > > > > > > > > +$basedir =~ s|(.*)/[^/]*|$1|; > > > > > > > > + > > > > > > > > +# Get rid of a testfile from last run if it's there (just in case) > > > > > > > > +system("rm -f $basedir/watch_me"); > > > > > > > > + > > > > > > > > +# Create a new test file > > > > > > > > +system("touch $basedir/watch_me"); > > > > > > > > +system("chcon -t test_notify_file_t $basedir/watch_me"); > > > > > > > > + > > > > > > > > +## TESTS > > > > > > > > + > > > > > > > > +## TEST BASIC WATCH PERMISSION > > > > > > > > +# Should be able to set inotify watch > > > > > > > > +$exit_val = > > > > > > > > + system("runcon -t test_watch_t > > > > > > > > $basedir/test_inotify $basedir/watch_me 2>&1"); > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > + > > > > > > > > +# Should be able to set non-permissions based fanotify watch > > > > > > > > +$exit_val = system( > > > > > > > > + "runcon -t test_watch_t > > > > > > > > $basedir/test_fanotify $basedir/watch_me 2>&1"); > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > + > > > > > > > > +# Should NOT be able to set permission based fanotify watch > > > > > > > > +$exit_val = system( > > > > > > > > + "runcon -t test_watch_t > > > > > > > > $basedir/test_fanotify -p $basedir/watch_me > > > > > > > > 2>&1"); > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > + > > > > > > > > +# Should NOT be able to set read based fanotify watch > > > > > > > > +$exit_val = system( > > > > > > > > + "runcon -t test_watch_t > > > > > > > > $basedir/test_fanotify -r $basedir/watch_me > > > > > > > > 2>&1"); > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > + > > > > > > > > +# Should NOT be able to set read based inotify watch > > > > > > > > +$exit_val = system( > > > > > > > > + "runcon -t test_watch_t > > > > > > > > $basedir/test_inotify -r $basedir/watch_me > > > > > > > > 2>&1"); > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > + > > > > > > > > +## TEST PERM WATCH > > > > > > > > +# Should be able to set permission based fanotify watch > > > > > > > > +$exit_val = system( > > > > > > > > +"runcon -t test_perm_watch_t > > > > > > > > $basedir/test_fanotify -p $basedir/watch_me > > > > > > > > 2>&1" > > > > > > > > +); > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > + > > > > > > > > +# Should NOT be able to set watch of accesses > > > > > > > > +$exit_val = system( > > > > > > > > +"runcon -t test_perm_watch_t > > > > > > > > $basedir/test_fanotify -r $basedir/watch_me > > > > > > > > 2>&1" > > > > > > > > +); > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > + > > > > > > > > +## TEST READ NO PERM WATCH PERMSISSIONS > > > > > > > > +# Should NOT be able to set read and perm watch > > > > > > > > +$exit_val = system( > > > > > > > > +"runcon -t test_read_watch_t > > > > > > > > $basedir/test_fanotify -p -r $basedir/watch_me > > > > > > > > 2>&1" > > > > > > > > +); > > > > > > > > +ok($exit_val); # should fail > > > > > > > > + > > > > > > > > +# Should be able to set read inotify watch > > > > > > > > +$exit_val = system( > > > > > > > > +"runcon -t test_read_watch_t > > > > > > > > $basedir/test_inotify -r $basedir/watch_me 2>&1" > > > > > > > > +); > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > + > > > > > > > > +## TEST READ WITH PERM WATCH PERMSISSIONS > > > > > > > > +# Should be able to set read and perm watch > > > > > > > > +$exit_val = system( > > > > > > > > +"runcon -t test_perm_read_watch_t > > > > > > > > $basedir/test_fanotify -p -r $basedir/watch_me > > > > > > > > 2>&1" > > > > > > > > +); > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > + > > > > > > > > +## TEST NO WATCH PERMSISSIONS > > > > > > > > +# Should NOT be able to set inotify watch > > > > > > > > +$exit_val = system( > > > > > > > > + "runcon -t test_no_watch_t > > > > > > > > $basedir/test_inotify $basedir/watch_me 2>&1"); > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > + > > > > > > > > +# Should NOT be able to set any fanotify watch > > > > > > > > +$exit_val = system( > > > > > > > > + "runcon -t test_no_watch_t > > > > > > > > $basedir/test_fanotify $basedir/watch_me 2>&1"); > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > + > > > > > > > > +## TEST READ ONLY > > > > > > > > +# Should NOT be able to get read-write descriptor > > > > > > > > +$exit_val = system( > > > > > > > > + "runcon -t test_rdonly_t > > > > > > > > $basedir/test_fanotify -l $basedir/watch_me > > > > > > > > 2>&1"); > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > + > > > > > > > > +# Should be able to get read-write descriptor > > > > > > > > +$exit_val = system( > > > > > > > > + "runcon -t test_watch_t > > > > > > > > $basedir/test_fanotify -l $basedir/watch_me > > > > > > > > 2>&1"); > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > + > > > > > > > > +# Clean up test file > > > > > > > > +system("rm -f $basedir/watch_me"); > > > > > > > > diff --git a/tests/notify/test_fanotify.c > > > > > > > > b/tests/notify/test_fanotify.c > > > > > > > > new file mode 100644 > > > > > > > > index 0000000..fff773f > > > > > > > > --- /dev/null > > > > > > > > +++ b/tests/notify/test_fanotify.c > > > > > > > > @@ -0,0 +1,105 @@ > > > > > > > > +#define _GNU_SOURCE 1 > > > > > > > > + > > > > > > > > +#include <stdio.h> > > > > > > > > +#include <stdlib.h> > > > > > > > > + > > > > > > > > +#include <getopt.h> > > > > > > > > + > > > > > > > > +#include <fcntl.h> > > > > > > > > +#include <poll.h> > > > > > > > > +#include <sys/fanotify.h> > > > > > > > > +#include <unistd.h> > > > > > > > > + > > > > > > > > +void printUsage() > > > > > > > > +{ > > > > > > > > + fprintf(stderr, "Usage: test_fanotify [-p] > > > > > > > > [-r] [-l] file_name\n"); > > > > > > > > + exit(1); > > > > > > > > +} > > > > > > > > + > > > > > > > > +int main(int argc, char *argv[]) > > > > > > > > +{ > > > > > > > > + if (argc < 2) { > > > > > > > > + printUsage(); > > > > > > > > + } > > > > > > > > + > > > > > > > > + int fd, ret, arg; > > > > > > > > + int mask = FAN_OPEN; // default mask > > > > > > > > + int listening = 0; > > > > > > > > + > > > > > > > > + // the -p flag will test for watch_with_perm > > > > > > > > + // the mask used at mark will contain FAN_OPEN_PERM > > > > > > > > + // > > > > > > > > + // the -r flag will test for watching > > > > > > > > accesses to files for reads > > > > > > > > + // the mask will contain FAN_ACCESS > > > > > > > > + while ((arg = getopt(argc, argv, "prl")) != -1) { > > > > > > > > + switch (arg) { > > > > > > > > + case 'p': > > > > > > > > + mask |= FAN_OPEN_PERM; > > > > > > > > + break; > > > > > > > > + case 'r': > > > > > > > > + mask |= FAN_ACCESS; > > > > > > > > + break; > > > > > > > > + case 'l': > > > > > > > > + listening = 1; > > > > > > > > + break; > > > > > > > > + default: > > > > > > > > + printUsage(); > > > > > > > > + } > > > > > > > > + } > > > > > > > > + > > > > > > > > + // get file descriptor for new fanotify event queue > > > > > > > > + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); > > > > > > > > + if (fd < 0) { > > > > > > > > + perror("fanotify_init:bad file descriptor"); > > > > > > > > + exit(1); > > > > > > > > + } > > > > > > > > + > > > > > > > > + // mark a filesystem object and add mark to event queue > > > > > > > > + // get notifications on file opens, accesses, and closes > > > > > > > > + // use current working directory as base dir > > > > > > > > + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, > > > > > > > > AT_FDCWD, argv[optind]); > > > > > > > > + > > > > > > > > + if (ret < 0) { > > > > > > > > + perror("test_fanotify:watch denied"); > > > > > > > > + exit(1); > > > > > > > > + } > > > > > > > > + > > > > > > > > + // logic to actually listen for an event if > > > > > > > > the -l flag is passed > > > > > > > > + // this is used to test if an app with > > > > > > > > read-only access can get a read/write > > > > > > > > + // handle to the watched file > > > > > > > > + if (listening) { > > > > > > > > + if (fork() == 0) { // fork a child > > > > > > > > process to cause an event on the file > > > > > > > > + FILE *f; > > > > > > > > + > > > > > > > > + f = fopen(argv[optind], "r"); // open file for reading > > > > > > > > + fgetc(f); // read char from file > > > > > > > > + > > > > > > > > + fclose(f); > > > > > > > > + } else { // logic to watch for events > > > > > > > > and try to access file read/write > > > > > > > > + struct pollfd fds; > > > > > > > > + fds.fd = fd; > > > > > > > > + fds.events = POLLIN; > > > > > > > > + > > > > > > > > + while (listening) { > > > > > > > > + int polled = poll(&fds, 1, 1); > > > > > > > > + if (polled > 0) { > > > > > > > > + if (fds.revents & POLLIN) { > > > > > > > > + struct fanotify_event_metadata buff[200]; > > > > > > > > + > > > > > > > > + size_t len = read(fd, > > > > > > > > (void *)&buff, sizeof(buff)); > > > > > > > > + if (len == -1) { > > > > > > > > + > > > > > > > > perror("test_fanotify:can't open file"); > > > > > > > > + exit(1); > > > > > > > > + } else { > > > > > > > > + listening = 0; > > > > > > > > + break; > > > > > > > > + } > > > > > > > > + } > > > > > > > > + } else if (polled == -1) { > > > > > > > > + listening = 0; > > > > > > > > + } > > > > > > > > + } > > > > > > > > + } > > > > > > > > + } > > > > > > > > + exit(0); > > > > > > > > +} > > > > > > > > diff --git a/tests/notify/test_inotify.c > > > > > > > > b/tests/notify/test_inotify.c > > > > > > > > new file mode 100644 > > > > > > > > index 0000000..17c3565 > > > > > > > > --- /dev/null > > > > > > > > +++ b/tests/notify/test_inotify.c > > > > > > > > @@ -0,0 +1,43 @@ > > > > > > > > +#include <stdio.h> > > > > > > > > +#include <stdlib.h> > > > > > > > > +#include <sys/inotify.h> > > > > > > > > +#include <getopt.h> > > > > > > > > + > > > > > > > > +int main(int argc, char *argv[]) > > > > > > > > +{ > > > > > > > > + if (argc < 2) { > > > > > > > > + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); > > > > > > > > + exit(1); > > > > > > > > + } > > > > > > > > + > > > > > > > > + int fd, wd, arg; > > > > > > > > + int mask = IN_MODIFY; > > > > > > > > + > > > > > > > > + while ((arg = getopt(argc, argv, "pr")) != -1) { > > > > > > > > + switch (arg) { > > > > > > > > + case 'r': > > > > > > > > + mask |= IN_ACCESS; > > > > > > > > + break; > > > > > > > > + default: > > > > > > > > + fprintf(stderr, "Usage: > > > > > > > > test_inotify [-r] file_name\n"); > > > > > > > > + exit(1); > > > > > > > > + } > > > > > > > > + } > > > > > > > > + > > > > > > > > + // get new file descriptor for inotify access > > > > > > > > + fd = inotify_init(); > > > > > > > > + if (fd < 0) { > > > > > > > > + perror("inotify_init:bad file descriptor"); > > > > > > > > + exit(1); > > > > > > > > + } > > > > > > > > + > > > > > > > > + // set watch on file and get watch > > > > > > > > descriptor for accessing events on it > > > > > > > > + wd = inotify_add_watch(fd, argv[optind], mask); > > > > > > > > + > > > > > > > > + if (wd < 0) { > > > > > > > > + perror("test_inotify:watch denied"); > > > > > > > > + exit(1); > > > > > > > > + } > > > > > > > > + > > > > > > > > + exit(0); > > > > > > > > +} > > > > > > > > -- > > > > > > > > 2.21.0 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
On 9/10/19 11:22 AM, Dominick Grift wrote: > On Tue, Sep 10, 2019 at 11:02:16AM -0400, Stephen Smalley wrote: >> On 9/10/19 10:59 AM, Stephen Smalley wrote: >>> On 9/10/19 10:54 AM, Stephen Smalley wrote: >>>> On 9/10/19 10:40 AM, Stephen Smalley wrote: >>>>> On 9/10/19 10:15 AM, Dominick Grift wrote: >>>>>> On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: >>>>>>> On 9/10/19 1:59 AM, Dominick Grift wrote: >>>>>>>> On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: >>>>>>>>> Added a suite to test permissions for setting >>>>>>>>> inotify and fanotify watches >>>>>>>>> on filesystem objects. Tests watch, >>>>>>>>> watch_with_perm, and watch_reads permissions. >>>>>>>> >>>>>>>> Ive also "tested" the fsnotify patch. And my tests >>>>>>>> indicate that this might cause issues: >>>>>>>> >>>>>>>> I added the access vectors to my policy, but on >>>>>>>> older systems (debian 10) cron fails to start >>>>>>>> cron needs the "entrypoint" permission on >>>>>>>> /etc/crontab but it looks like appending the "watch" >>>>>>>> access vectors to common-file disrupted the ordering >>>>>>>> The result is that now i have to allow cron to >>>>>>>> "watch_read" /etc/crontab even though the neither >>>>>>>> kernel nor selinux user space are aware of the >>>>>>>> fsnotify access vectors >>>>>>>> It seems the cron selinux code got confused and now >>>>>>>> thinks watch_read is entrypoint (its using selinux >>>>>>>> code to determine whether it can manually transition >>>>>>>> to cronjob domains on crontabs) >>>>>>>> >>>>>>>> I am hoping this issue with resolve itself on >>>>>>>> systems with kernels and user spaces that suppose >>>>>>>> fsnotify. >>>>>>>> However unless i am overlooking something this is >>>>>>>> still likely to disrupt compatibility >>>>>>> >>>>>>> So, IIUC, the issue is that: >>>>>>> a) older cron was directly using the fixed >>>>>>> FILE__ENTRYPOINT definition from >>>>>>> libselinux in a security_compute_av() call rather than >>>>>>> dynamically looking >>>>>>> up entrypoint permission, >>>>>>> b) the value of the file entrypoint permission in policy >>>>>>> has changed because >>>>>>> you updated your policy and chose to place the watch* >>>>>>> permissions in the >>>>>>> common file definition to match the kernel. >>>>>>> >>>>>>> Note that you could have instead sprinkled copies of the >>>>>>> watch* permissions >>>>>>> across all of the individual file/dir/*_file classes and >>>>>>> placed them at the >>>>>>> end of the classes if you wanted to avoid this >>>>>>> compatibility issue. The >>>>>>> policy and kernel definitions no longer need to be >>>>>>> identical; the kernel >>>>>>> will dynamically map between them for its own permission checks. >>>>>>> >>>>>>> Also, this should have already been broken for you when >>>>>>> map permission was >>>>>>> added, which would have shown up as execute_no_trans >>>>>>> being checked instead >>>>>>> of entrypoint. This was already filed as a bug on cron >>>>>>> in debian here: >>>>>>> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 >>>>>>> >>>>>>> So, wrt compatibility, IIUC: >>>>>>> - the kernel change does not break compatibility for old policy + old >>>>>>> userspace, >>>>>>> - new policy can choose to add the new permissions in a >>>>>>> backward-compatible >>>>>>> manner if desired, although refpolicy has already chosen >>>>>>> not to do this for >>>>>>> map permission, >>>>>>> - the offending code in cron produces build warnings >>>>>>> that were introduced in >>>>>>> 2014 in libselinux to update their code to use the dynamic class/perm >>>>>>> mapping support, which would resolve the issue. >>>>>> >>>>>> this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d >>>>>> >>>>>> >>>>>> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x >>>>>> --common common_file >>>>>> >>>>>> Commons: 1 >>>>>> common common_file >>>>>> { >>>>>> append >>>>>> lock >>>>>> mounton >>>>>> unlink >>>>>> read >>>>>> create >>>>>> quotaon >>>>>> execute >>>>>> setattr >>>>>> map >>>>>> relabelto >>>>>> rename >>>>>> link >>>>>> ioctl >>>>>> getattr >>>>>> relabelfrom >>>>>> } >>>>>> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile >>>>>> >>>>>> Classes: 1 >>>>>> class file >>>>>> inherits common_file >>>>>> { >>>>>> execmod >>>>>> watch >>>>>> write >>>>>> watch_reads >>>>>> execute_no_trans >>>>>> watch_mount >>>>>> watch_with_perm >>>>>> open >>>>>> watch_sb >>>>>> audit_access >>>>>> entrypoint >>>>>> } >>>>> >>>>> If you want to preserve compatibility with userspace using fixed >>>>> definitions of FILE__ENTRYPOINT, then you have to insert any new >>>>> file permissions after the current entrypoint permission in the >>>>> class file. So watch and friends have to go after it, not before >>>>> it. >>>>> >>>>> Also, since the kernel always uses FILE__WATCH* in the check >>>>> code rather than distinguishing by class, the watch* permissions >>>>> need to be at the same offset in all of the file classes. The >>>>> same is true of the other file permissions. It looks like you >>>>> may have other permissions out of sync across the file classes >>>>> e.g. execmod, open, audit_access, that need to be aligned or the >>>>> kernel could check the wrong permission. >>>> >>>> Sorry, the last para isn't correct - it should get mapped correctly >>>> per class. But you do need to add the permissions after entrypoint >>>> in the file class to avoid displacing its value. >>> >>> Also, it looks like your file class permission order differs in other >>> incompatible ways. If you want it to be compatible with the deprecated >>> libselinux headers, the requisite order would be: >>> class file >>> inherits common_file >>> { >>> execute_no_trans >>> entrypoint >>> execmod >>> open >>> audit_access >>> map >> >> Sorry, insert watch* permissions here. > > I applied brute force: > > the map permission can be part of common_file just fine. > the audit_access av (which was clearly introduced after entrypoint can precede entrypoint just fine. > > The problem is the prescence of the fsnotify access vector in general. Moving them out of common_file and after entrypoint does not make a difference. > As soon as I remove the fsnotify av's things start to work. > > In other words. besides the precensce of the fsnotify access vectors everything (seemingly) is in order > Now for me the question remains: will this issue automatically resolve itself as soon as userspace and kernel support the fsnotify av That doesn't make any sense to me. Sounds like a bug somewhere. Anything that changes the permission bit value in the policy for FILE__ENTRYPOINT is going to break legacy crond that is using the hardcoded value from the deprecated libselinux headers. So adding permissions at the end of the file class should be fine. Adding or removing to/from common file should break. I can't explain the behavior you are seeing. >> >>> } >>> >>>> >>>>> >>>>>> >>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>> Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> >>>>>>>>> --- >>>>>>>>> policy/Makefile | 4 ++ >>>>>>>>> policy/test_notify.te | 74 ++++++++++++++++++++++++ >>>>>>>>> tests/Makefile | 4 ++ >>>>>>>>> tests/notify/Makefile | 5 ++ >>>>>>>>> tests/notify/test | 101 >>>>>>>>> +++++++++++++++++++++++++++++++++ >>>>>>>>> tests/notify/test_fanotify.c | 105 >>>>>>>>> +++++++++++++++++++++++++++++++++++ >>>>>>>>> tests/notify/test_inotify.c | 43 ++++++++++++++ >>>>>>>>> 7 files changed, 336 insertions(+) >>>>>>>>> create mode 100644 policy/test_notify.te >>>>>>>>> create mode 100644 tests/notify/Makefile >>>>>>>>> create mode 100755 tests/notify/test >>>>>>>>> create mode 100644 tests/notify/test_fanotify.c >>>>>>>>> create mode 100644 tests/notify/test_inotify.c >>>>>>>>> >>>>>>>>> diff --git a/policy/Makefile b/policy/Makefile >>>>>>>>> index 305b572..65f88c5 100644 >>>>>>>>> --- a/policy/Makefile >>>>>>>>> +++ b/policy/Makefile >>>>>>>>> @@ -71,6 +71,10 @@ ifeq ($(shell grep -q >>>>>>>>> corenet_sctp_bind_all_nodes >>>>>>>>> $(POLDEV)/include/kernel/coren >>>>>>>>> TARGETS += test_sctp.te >>>>>>>>> endif >>>>>>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>>>>>> $(POLDEV)/include/support/all_perms.spt && echo >>>>>>>>> true),true) >>>>>>>>> +TARGETS+=test_notify.te >>>>>>>>> +endif >>>>>>>>> + >>>>>>>>> ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) >>>>>>>>> TARGETS:=$(filter-out test_overlayfs.te >>>>>>>>> test_mqueue.te, $(TARGETS)) >>>>>>>>> endif >>>>>>>>> diff --git a/policy/test_notify.te b/policy/test_notify.te >>>>>>>>> new file mode 100644 >>>>>>>>> index 0000000..8ba6f1a >>>>>>>>> --- /dev/null >>>>>>>>> +++ b/policy/test_notify.te >>>>>>>>> @@ -0,0 +1,74 @@ >>>>>>>>> +#################################################### >>>>>>>>> +# Policy for testing inoftify and fanotify watches # >>>>>>>>> +#################################################### >>>>>>>>> + >>>>>>>>> +attribute test_notify_domain; >>>>>>>>> + >>>>>>>>> +# Type for the file on which we want to set a watch >>>>>>>>> +type test_notify_file_t; >>>>>>>>> +files_type(test_notify_file_t); >>>>>>>>> + >>>>>>>>> +# Domain for the process which CAN set a non-permission watch >>>>>>>>> +type test_watch_t; >>>>>>>>> +domain_type(test_watch_t); >>>>>>>>> +unconfined_runs_test(test_watch_t); >>>>>>>>> + >>>>>>>>> +typeattribute test_watch_t test_notify_domain; >>>>>>>>> +typeattribute test_watch_t testdomain; >>>>>>>>> + >>>>>>>>> +allow test_notify_domain self:capability sys_admin; >>>>>>>>> + >>>>>>>>> +allow test_watch_t test_notify_file_t:file { >>>>>>>>> read write open watch }; >>>>>>>>> + >>>>>>>>> +# Domain for the process which CAN set a NON-access watch on a file >>>>>>>>> +type test_perm_watch_t; >>>>>>>>> +domain_type(test_perm_watch_t); >>>>>>>>> +unconfined_runs_test(test_perm_watch_t); >>>>>>>>> + >>>>>>>>> +typeattribute test_perm_watch_t test_notify_domain; >>>>>>>>> +typeattribute test_perm_watch_t testdomain; >>>>>>>>> + >>>>>>>>> +allow test_perm_watch_t test_notify_file_t:file >>>>>>>>> { read write open watch watch_with_perm }; >>>>>>>>> + >>>>>>>>> +# Domain which CAN set a NON-perm watch which MAY read accesses >>>>>>>>> +type test_read_watch_t; >>>>>>>>> +domain_type(test_read_watch_t); >>>>>>>>> +unconfined_runs_test(test_read_watch_t); >>>>>>>>> + >>>>>>>>> +typeattribute test_read_watch_t test_notify_domain; >>>>>>>>> +typeattribute test_read_watch_t testdomain; >>>>>>>>> + >>>>>>>>> +allow test_read_watch_t test_notify_file_t:file >>>>>>>>> { read write open watch watch_reads }; >>>>>>>>> + >>>>>>>>> +# Domain which CAN set any watch which CAN read accesses >>>>>>>>> +type test_perm_read_watch_t; >>>>>>>>> +domain_type(test_perm_read_watch_t); >>>>>>>>> +unconfined_runs_test(test_perm_read_watch_t); >>>>>>>>> + >>>>>>>>> +typeattribute test_perm_read_watch_t test_notify_domain; >>>>>>>>> +typeattribute test_perm_read_watch_t testdomain; >>>>>>>>> + >>>>>>>>> +allow test_perm_read_watch_t >>>>>>>>> test_notify_file_t:file { read write open watch >>>>>>>>> watch_with_perm watch_reads }; >>>>>>>>> + >>>>>>>>> +# Domain which CANNOT set any watches >>>>>>>>> +type test_no_watch_t; >>>>>>>>> +domain_type(test_no_watch_t); >>>>>>>>> +unconfined_runs_test(test_no_watch_t); >>>>>>>>> + >>>>>>>>> +typeattribute test_no_watch_t test_notify_domain; >>>>>>>>> +typeattribute test_no_watch_t testdomain; >>>>>>>>> + >>>>>>>>> +allow test_no_watch_t test_notify_file_t:file { read write open }; >>>>>>>>> + >>>>>>>>> +# Domain which has no write access but can watch >>>>>>>>> +type test_rdonly_t; >>>>>>>>> +domain_type(test_rdonly_t); >>>>>>>>> +unconfined_runs_test(test_rdonly_t); >>>>>>>>> + >>>>>>>>> +typeattribute test_rdonly_t test_notify_domain; >>>>>>>>> +typeattribute test_rdonly_t testdomain; >>>>>>>>> + >>>>>>>>> +allow test_rdonly_t test_notify_file_t:file { read open watch }; >>>>>>>>> + >>>>>>>>> +miscfiles_domain_entry_test_files(test_notify_domain); >>>>>>>>> +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); >>>>>>>>> diff --git a/tests/Makefile b/tests/Makefile >>>>>>>>> index 63aa325..b99c96e 100644 >>>>>>>>> --- a/tests/Makefile >>>>>>>>> +++ b/tests/Makefile >>>>>>>>> @@ -50,6 +50,10 @@ ifeq ($(shell grep >>>>>>>>> "^SELINUX_INFINIBAND_PKEY_TEST=" >>>>>>>>> infiniband_pkey/ibpkey_test. >>>>>>>>> SUBDIRS += infiniband_pkey >>>>>>>>> endif >>>>>>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>>>>>> $(POLDEV)/include/support/all_perms.spt && echo >>>>>>>>> true),true) >>>>>>>>> +SUBDIRS+=notify >>>>>>>>> +endif >>>>>>>>> + >>>>>>>>> ifeq ($(DISTRO),RHEL4) >>>>>>>>> SUBDIRS:=$(filter-out bounds dyntrace >>>>>>>>> dyntrans inet_socket mmap nnp_nosuid overlay >>>>>>>>> unix_socket, $(SUBDIRS)) >>>>>>>>> endif >>>>>>>>> diff --git a/tests/notify/Makefile b/tests/notify/Makefile >>>>>>>>> new file mode 100644 >>>>>>>>> index 0000000..78c4b3b >>>>>>>>> --- /dev/null >>>>>>>>> +++ b/tests/notify/Makefile >>>>>>>>> @@ -0,0 +1,5 @@ >>>>>>>>> +TARGETS=test_inotify test_fanotify >>>>>>>>> + >>>>>>>>> +all: $(TARGETS) >>>>>>>>> +clean: >>>>>>>>> + rm -f $(TARGETS) >>>>>>>>> diff --git a/tests/notify/test b/tests/notify/test >>>>>>>>> new file mode 100755 >>>>>>>>> index 0000000..21f03de >>>>>>>>> --- /dev/null >>>>>>>>> +++ b/tests/notify/test >>>>>>>>> @@ -0,0 +1,101 @@ >>>>>>>>> +#!/usr/bin/perl >>>>>>>>> + >>>>>>>>> +use Test; >>>>>>>>> +BEGIN { plan tests => 14 } # number of tests to run >>>>>>>>> + >>>>>>>>> +# help the test script locate itself >>>>>>>>> +$basedir = $0; >>>>>>>>> +$basedir =~ s|(.*)/[^/]*|$1|; >>>>>>>>> + >>>>>>>>> +# Get rid of a testfile from last run if it's there (just in case) >>>>>>>>> +system("rm -f $basedir/watch_me"); >>>>>>>>> + >>>>>>>>> +# Create a new test file >>>>>>>>> +system("touch $basedir/watch_me"); >>>>>>>>> +system("chcon -t test_notify_file_t $basedir/watch_me"); >>>>>>>>> + >>>>>>>>> +## TESTS >>>>>>>>> + >>>>>>>>> +## TEST BASIC WATCH PERMISSION >>>>>>>>> +# Should be able to set inotify watch >>>>>>>>> +$exit_val = >>>>>>>>> + system("runcon -t test_watch_t >>>>>>>>> $basedir/test_inotify $basedir/watch_me 2>&1"); >>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>> + >>>>>>>>> +# Should be able to set non-permissions based fanotify watch >>>>>>>>> +$exit_val = system( >>>>>>>>> + "runcon -t test_watch_t >>>>>>>>> $basedir/test_fanotify $basedir/watch_me 2>&1"); >>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>> + >>>>>>>>> +# Should NOT be able to set permission based fanotify watch >>>>>>>>> +$exit_val = system( >>>>>>>>> + "runcon -t test_watch_t >>>>>>>>> $basedir/test_fanotify -p $basedir/watch_me >>>>>>>>> 2>&1"); >>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>> + >>>>>>>>> +# Should NOT be able to set read based fanotify watch >>>>>>>>> +$exit_val = system( >>>>>>>>> + "runcon -t test_watch_t >>>>>>>>> $basedir/test_fanotify -r $basedir/watch_me >>>>>>>>> 2>&1"); >>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>> + >>>>>>>>> +# Should NOT be able to set read based inotify watch >>>>>>>>> +$exit_val = system( >>>>>>>>> + "runcon -t test_watch_t >>>>>>>>> $basedir/test_inotify -r $basedir/watch_me >>>>>>>>> 2>&1"); >>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>> + >>>>>>>>> +## TEST PERM WATCH >>>>>>>>> +# Should be able to set permission based fanotify watch >>>>>>>>> +$exit_val = system( >>>>>>>>> +"runcon -t test_perm_watch_t >>>>>>>>> $basedir/test_fanotify -p $basedir/watch_me >>>>>>>>> 2>&1" >>>>>>>>> +); >>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>> + >>>>>>>>> +# Should NOT be able to set watch of accesses >>>>>>>>> +$exit_val = system( >>>>>>>>> +"runcon -t test_perm_watch_t >>>>>>>>> $basedir/test_fanotify -r $basedir/watch_me >>>>>>>>> 2>&1" >>>>>>>>> +); >>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>> + >>>>>>>>> +## TEST READ NO PERM WATCH PERMSISSIONS >>>>>>>>> +# Should NOT be able to set read and perm watch >>>>>>>>> +$exit_val = system( >>>>>>>>> +"runcon -t test_read_watch_t >>>>>>>>> $basedir/test_fanotify -p -r $basedir/watch_me >>>>>>>>> 2>&1" >>>>>>>>> +); >>>>>>>>> +ok($exit_val); # should fail >>>>>>>>> + >>>>>>>>> +# Should be able to set read inotify watch >>>>>>>>> +$exit_val = system( >>>>>>>>> +"runcon -t test_read_watch_t >>>>>>>>> $basedir/test_inotify -r $basedir/watch_me 2>&1" >>>>>>>>> +); >>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>> + >>>>>>>>> +## TEST READ WITH PERM WATCH PERMSISSIONS >>>>>>>>> +# Should be able to set read and perm watch >>>>>>>>> +$exit_val = system( >>>>>>>>> +"runcon -t test_perm_read_watch_t >>>>>>>>> $basedir/test_fanotify -p -r $basedir/watch_me >>>>>>>>> 2>&1" >>>>>>>>> +); >>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>> + >>>>>>>>> +## TEST NO WATCH PERMSISSIONS >>>>>>>>> +# Should NOT be able to set inotify watch >>>>>>>>> +$exit_val = system( >>>>>>>>> + "runcon -t test_no_watch_t >>>>>>>>> $basedir/test_inotify $basedir/watch_me 2>&1"); >>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>> + >>>>>>>>> +# Should NOT be able to set any fanotify watch >>>>>>>>> +$exit_val = system( >>>>>>>>> + "runcon -t test_no_watch_t >>>>>>>>> $basedir/test_fanotify $basedir/watch_me 2>&1"); >>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>> + >>>>>>>>> +## TEST READ ONLY >>>>>>>>> +# Should NOT be able to get read-write descriptor >>>>>>>>> +$exit_val = system( >>>>>>>>> + "runcon -t test_rdonly_t >>>>>>>>> $basedir/test_fanotify -l $basedir/watch_me >>>>>>>>> 2>&1"); >>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>> + >>>>>>>>> +# Should be able to get read-write descriptor >>>>>>>>> +$exit_val = system( >>>>>>>>> + "runcon -t test_watch_t >>>>>>>>> $basedir/test_fanotify -l $basedir/watch_me >>>>>>>>> 2>&1"); >>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>> + >>>>>>>>> +# Clean up test file >>>>>>>>> +system("rm -f $basedir/watch_me"); >>>>>>>>> diff --git a/tests/notify/test_fanotify.c >>>>>>>>> b/tests/notify/test_fanotify.c >>>>>>>>> new file mode 100644 >>>>>>>>> index 0000000..fff773f >>>>>>>>> --- /dev/null >>>>>>>>> +++ b/tests/notify/test_fanotify.c >>>>>>>>> @@ -0,0 +1,105 @@ >>>>>>>>> +#define _GNU_SOURCE 1 >>>>>>>>> + >>>>>>>>> +#include <stdio.h> >>>>>>>>> +#include <stdlib.h> >>>>>>>>> + >>>>>>>>> +#include <getopt.h> >>>>>>>>> + >>>>>>>>> +#include <fcntl.h> >>>>>>>>> +#include <poll.h> >>>>>>>>> +#include <sys/fanotify.h> >>>>>>>>> +#include <unistd.h> >>>>>>>>> + >>>>>>>>> +void printUsage() >>>>>>>>> +{ >>>>>>>>> + fprintf(stderr, "Usage: test_fanotify [-p] >>>>>>>>> [-r] [-l] file_name\n"); >>>>>>>>> + exit(1); >>>>>>>>> +} >>>>>>>>> + >>>>>>>>> +int main(int argc, char *argv[]) >>>>>>>>> +{ >>>>>>>>> + if (argc < 2) { >>>>>>>>> + printUsage(); >>>>>>>>> + } >>>>>>>>> + >>>>>>>>> + int fd, ret, arg; >>>>>>>>> + int mask = FAN_OPEN; // default mask >>>>>>>>> + int listening = 0; >>>>>>>>> + >>>>>>>>> + // the -p flag will test for watch_with_perm >>>>>>>>> + // the mask used at mark will contain FAN_OPEN_PERM >>>>>>>>> + // >>>>>>>>> + // the -r flag will test for watching >>>>>>>>> accesses to files for reads >>>>>>>>> + // the mask will contain FAN_ACCESS >>>>>>>>> + while ((arg = getopt(argc, argv, "prl")) != -1) { >>>>>>>>> + switch (arg) { >>>>>>>>> + case 'p': >>>>>>>>> + mask |= FAN_OPEN_PERM; >>>>>>>>> + break; >>>>>>>>> + case 'r': >>>>>>>>> + mask |= FAN_ACCESS; >>>>>>>>> + break; >>>>>>>>> + case 'l': >>>>>>>>> + listening = 1; >>>>>>>>> + break; >>>>>>>>> + default: >>>>>>>>> + printUsage(); >>>>>>>>> + } >>>>>>>>> + } >>>>>>>>> + >>>>>>>>> + // get file descriptor for new fanotify event queue >>>>>>>>> + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); >>>>>>>>> + if (fd < 0) { >>>>>>>>> + perror("fanotify_init:bad file descriptor"); >>>>>>>>> + exit(1); >>>>>>>>> + } >>>>>>>>> + >>>>>>>>> + // mark a filesystem object and add mark to event queue >>>>>>>>> + // get notifications on file opens, accesses, and closes >>>>>>>>> + // use current working directory as base dir >>>>>>>>> + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, >>>>>>>>> AT_FDCWD, argv[optind]); >>>>>>>>> + >>>>>>>>> + if (ret < 0) { >>>>>>>>> + perror("test_fanotify:watch denied"); >>>>>>>>> + exit(1); >>>>>>>>> + } >>>>>>>>> + >>>>>>>>> + // logic to actually listen for an event if >>>>>>>>> the -l flag is passed >>>>>>>>> + // this is used to test if an app with >>>>>>>>> read-only access can get a read/write >>>>>>>>> + // handle to the watched file >>>>>>>>> + if (listening) { >>>>>>>>> + if (fork() == 0) { // fork a child >>>>>>>>> process to cause an event on the file >>>>>>>>> + FILE *f; >>>>>>>>> + >>>>>>>>> + f = fopen(argv[optind], "r"); // open file for reading >>>>>>>>> + fgetc(f); // read char from file >>>>>>>>> + >>>>>>>>> + fclose(f); >>>>>>>>> + } else { // logic to watch for events >>>>>>>>> and try to access file read/write >>>>>>>>> + struct pollfd fds; >>>>>>>>> + fds.fd = fd; >>>>>>>>> + fds.events = POLLIN; >>>>>>>>> + >>>>>>>>> + while (listening) { >>>>>>>>> + int polled = poll(&fds, 1, 1); >>>>>>>>> + if (polled > 0) { >>>>>>>>> + if (fds.revents & POLLIN) { >>>>>>>>> + struct fanotify_event_metadata buff[200]; >>>>>>>>> + >>>>>>>>> + size_t len = read(fd, >>>>>>>>> (void *)&buff, sizeof(buff)); >>>>>>>>> + if (len == -1) { >>>>>>>>> + >>>>>>>>> perror("test_fanotify:can't open file"); >>>>>>>>> + exit(1); >>>>>>>>> + } else { >>>>>>>>> + listening = 0; >>>>>>>>> + break; >>>>>>>>> + } >>>>>>>>> + } >>>>>>>>> + } else if (polled == -1) { >>>>>>>>> + listening = 0; >>>>>>>>> + } >>>>>>>>> + } >>>>>>>>> + } >>>>>>>>> + } >>>>>>>>> + exit(0); >>>>>>>>> +} >>>>>>>>> diff --git a/tests/notify/test_inotify.c >>>>>>>>> b/tests/notify/test_inotify.c >>>>>>>>> new file mode 100644 >>>>>>>>> index 0000000..17c3565 >>>>>>>>> --- /dev/null >>>>>>>>> +++ b/tests/notify/test_inotify.c >>>>>>>>> @@ -0,0 +1,43 @@ >>>>>>>>> +#include <stdio.h> >>>>>>>>> +#include <stdlib.h> >>>>>>>>> +#include <sys/inotify.h> >>>>>>>>> +#include <getopt.h> >>>>>>>>> + >>>>>>>>> +int main(int argc, char *argv[]) >>>>>>>>> +{ >>>>>>>>> + if (argc < 2) { >>>>>>>>> + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); >>>>>>>>> + exit(1); >>>>>>>>> + } >>>>>>>>> + >>>>>>>>> + int fd, wd, arg; >>>>>>>>> + int mask = IN_MODIFY; >>>>>>>>> + >>>>>>>>> + while ((arg = getopt(argc, argv, "pr")) != -1) { >>>>>>>>> + switch (arg) { >>>>>>>>> + case 'r': >>>>>>>>> + mask |= IN_ACCESS; >>>>>>>>> + break; >>>>>>>>> + default: >>>>>>>>> + fprintf(stderr, "Usage: >>>>>>>>> test_inotify [-r] file_name\n"); >>>>>>>>> + exit(1); >>>>>>>>> + } >>>>>>>>> + } >>>>>>>>> + >>>>>>>>> + // get new file descriptor for inotify access >>>>>>>>> + fd = inotify_init(); >>>>>>>>> + if (fd < 0) { >>>>>>>>> + perror("inotify_init:bad file descriptor"); >>>>>>>>> + exit(1); >>>>>>>>> + } >>>>>>>>> + >>>>>>>>> + // set watch on file and get watch >>>>>>>>> descriptor for accessing events on it >>>>>>>>> + wd = inotify_add_watch(fd, argv[optind], mask); >>>>>>>>> + >>>>>>>>> + if (wd < 0) { >>>>>>>>> + perror("test_inotify:watch denied"); >>>>>>>>> + exit(1); >>>>>>>>> + } >>>>>>>>> + >>>>>>>>> + exit(0); >>>>>>>>> +} >>>>>>>>> -- >>>>>>>>> 2.21.0 >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> >
On Tue, Sep 10, 2019 at 12:25:44PM -0400, Stephen Smalley wrote: > On 9/10/19 11:22 AM, Dominick Grift wrote: > > On Tue, Sep 10, 2019 at 11:02:16AM -0400, Stephen Smalley wrote: > > > On 9/10/19 10:59 AM, Stephen Smalley wrote: > > > > On 9/10/19 10:54 AM, Stephen Smalley wrote: > > > > > On 9/10/19 10:40 AM, Stephen Smalley wrote: > > > > > > On 9/10/19 10:15 AM, Dominick Grift wrote: > > > > > > > On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: > > > > > > > > On 9/10/19 1:59 AM, Dominick Grift wrote: > > > > > > > > > On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: > > > > > > > > > > Added a suite to test permissions for setting > > > > > > > > > > inotify and fanotify watches > > > > > > > > > > on filesystem objects. Tests watch, > > > > > > > > > > watch_with_perm, and watch_reads permissions. > > > > > > > > > > > > > > > > > > Ive also "tested" the fsnotify patch. And my tests > > > > > > > > > indicate that this might cause issues: > > > > > > > > > > > > > > > > > > I added the access vectors to my policy, but on > > > > > > > > > older systems (debian 10) cron fails to start > > > > > > > > > cron needs the "entrypoint" permission on > > > > > > > > > /etc/crontab but it looks like appending the "watch" > > > > > > > > > access vectors to common-file disrupted the ordering > > > > > > > > > The result is that now i have to allow cron to > > > > > > > > > "watch_read" /etc/crontab even though the neither > > > > > > > > > kernel nor selinux user space are aware of the > > > > > > > > > fsnotify access vectors > > > > > > > > > It seems the cron selinux code got confused and now > > > > > > > > > thinks watch_read is entrypoint (its using selinux > > > > > > > > > code to determine whether it can manually transition > > > > > > > > > to cronjob domains on crontabs) > > > > > > > > > > > > > > > > > > I am hoping this issue with resolve itself on > > > > > > > > > systems with kernels and user spaces that suppose > > > > > > > > > fsnotify. > > > > > > > > > However unless i am overlooking something this is > > > > > > > > > still likely to disrupt compatibility > > > > > > > > > > > > > > > > So, IIUC, the issue is that: > > > > > > > > a) older cron was directly using the fixed > > > > > > > > FILE__ENTRYPOINT definition from > > > > > > > > libselinux in a security_compute_av() call rather than > > > > > > > > dynamically looking > > > > > > > > up entrypoint permission, > > > > > > > > b) the value of the file entrypoint permission in policy > > > > > > > > has changed because > > > > > > > > you updated your policy and chose to place the watch* > > > > > > > > permissions in the > > > > > > > > common file definition to match the kernel. > > > > > > > > > > > > > > > > Note that you could have instead sprinkled copies of the > > > > > > > > watch* permissions > > > > > > > > across all of the individual file/dir/*_file classes and > > > > > > > > placed them at the > > > > > > > > end of the classes if you wanted to avoid this > > > > > > > > compatibility issue. The > > > > > > > > policy and kernel definitions no longer need to be > > > > > > > > identical; the kernel > > > > > > > > will dynamically map between them for its own permission checks. > > > > > > > > > > > > > > > > Also, this should have already been broken for you when > > > > > > > > map permission was > > > > > > > > added, which would have shown up as execute_no_trans > > > > > > > > being checked instead > > > > > > > > of entrypoint. This was already filed as a bug on cron > > > > > > > > in debian here: > > > > > > > > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 > > > > > > > > > > > > > > > > So, wrt compatibility, IIUC: > > > > > > > > - the kernel change does not break compatibility for old policy + old > > > > > > > > userspace, > > > > > > > > - new policy can choose to add the new permissions in a > > > > > > > > backward-compatible > > > > > > > > manner if desired, although refpolicy has already chosen > > > > > > > > not to do this for > > > > > > > > map permission, > > > > > > > > - the offending code in cron produces build warnings > > > > > > > > that were introduced in > > > > > > > > 2014 in libselinux to update their code to use the dynamic class/perm > > > > > > > > mapping support, which would resolve the issue. > > > > > > > > > > > > > > this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d > > > > > > > > > > > > > > > > > > > > > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x > > > > > > > --common common_file > > > > > > > > > > > > > > Commons: 1 > > > > > > > common common_file > > > > > > > { > > > > > > > append > > > > > > > lock > > > > > > > mounton > > > > > > > unlink > > > > > > > read > > > > > > > create > > > > > > > quotaon > > > > > > > execute > > > > > > > setattr > > > > > > > map > > > > > > > relabelto > > > > > > > rename > > > > > > > link > > > > > > > ioctl > > > > > > > getattr > > > > > > > relabelfrom > > > > > > > } > > > > > > > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile > > > > > > > > > > > > > > Classes: 1 > > > > > > > class file > > > > > > > inherits common_file > > > > > > > { > > > > > > > execmod > > > > > > > watch > > > > > > > write > > > > > > > watch_reads > > > > > > > execute_no_trans > > > > > > > watch_mount > > > > > > > watch_with_perm > > > > > > > open > > > > > > > watch_sb > > > > > > > audit_access > > > > > > > entrypoint > > > > > > > } > > > > > > > > > > > > If you want to preserve compatibility with userspace using fixed > > > > > > definitions of FILE__ENTRYPOINT, then you have to insert any new > > > > > > file permissions after the current entrypoint permission in the > > > > > > class file. So watch and friends have to go after it, not before > > > > > > it. > > > > > > > > > > > > Also, since the kernel always uses FILE__WATCH* in the check > > > > > > code rather than distinguishing by class, the watch* permissions > > > > > > need to be at the same offset in all of the file classes. The > > > > > > same is true of the other file permissions. It looks like you > > > > > > may have other permissions out of sync across the file classes > > > > > > e.g. execmod, open, audit_access, that need to be aligned or the > > > > > > kernel could check the wrong permission. > > > > > > > > > > Sorry, the last para isn't correct - it should get mapped correctly > > > > > per class. But you do need to add the permissions after entrypoint > > > > > in the file class to avoid displacing its value. > > > > > > > > Also, it looks like your file class permission order differs in other > > > > incompatible ways. If you want it to be compatible with the deprecated > > > > libselinux headers, the requisite order would be: > > > > class file > > > > inherits common_file > > > > { > > > > execute_no_trans > > > > entrypoint > > > > execmod > > > > open > > > > audit_access > > > > map > > > > > > Sorry, insert watch* permissions here. > > > > I applied brute force: > > > > the map permission can be part of common_file just fine. > > the audit_access av (which was clearly introduced after entrypoint can precede entrypoint just fine. > > > > The problem is the prescence of the fsnotify access vector in general. Moving them out of common_file and after entrypoint does not make a difference. > > As soon as I remove the fsnotify av's things start to work. > > > > In other words. besides the precensce of the fsnotify access vectors everything (seemingly) is in order > > Now for me the question remains: will this issue automatically resolve itself as soon as userspace and kernel support the fsnotify av > > That doesn't make any sense to me. Sounds like a bug somewhere. Anything > that changes the permission bit value in the policy for FILE__ENTRYPOINT is > going to break legacy crond that is using the hardcoded value from the > deprecated libselinux headers. So adding permissions at the end of the file > class should be fine. Adding or removing to/from common file should break. > I can't explain the behavior you are seeing. It does not make sense to me either, but i believe it when i see it. Ive tried several times and just removing the fsnotify access vectors make it work. Whether i append them to common_file or whether i append them to the individual classes does not make a difference. BTW: this fixes it for me: https://lore.kernel.org/selinux/d706a78c-d6d0-13bb-c9af-7ec4365b9b44@debian.org/T/#u > > > > > > > > } > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> > > > > > > > > > > --- > > > > > > > > > > policy/Makefile | 4 ++ > > > > > > > > > > policy/test_notify.te | 74 ++++++++++++++++++++++++ > > > > > > > > > > tests/Makefile | 4 ++ > > > > > > > > > > tests/notify/Makefile | 5 ++ > > > > > > > > > > tests/notify/test | 101 > > > > > > > > > > +++++++++++++++++++++++++++++++++ > > > > > > > > > > tests/notify/test_fanotify.c | 105 > > > > > > > > > > +++++++++++++++++++++++++++++++++++ > > > > > > > > > > tests/notify/test_inotify.c | 43 ++++++++++++++ > > > > > > > > > > 7 files changed, 336 insertions(+) > > > > > > > > > > create mode 100644 policy/test_notify.te > > > > > > > > > > create mode 100644 tests/notify/Makefile > > > > > > > > > > create mode 100755 tests/notify/test > > > > > > > > > > create mode 100644 tests/notify/test_fanotify.c > > > > > > > > > > create mode 100644 tests/notify/test_inotify.c > > > > > > > > > > > > > > > > > > > > diff --git a/policy/Makefile b/policy/Makefile > > > > > > > > > > index 305b572..65f88c5 100644 > > > > > > > > > > --- a/policy/Makefile > > > > > > > > > > +++ b/policy/Makefile > > > > > > > > > > @@ -71,6 +71,10 @@ ifeq ($(shell grep -q > > > > > > > > > > corenet_sctp_bind_all_nodes > > > > > > > > > > $(POLDEV)/include/kernel/coren > > > > > > > > > > TARGETS += test_sctp.te > > > > > > > > > > endif > > > > > > > > > > +ifeq ($(shell grep -q all_file_perms.*watch > > > > > > > > > > $(POLDEV)/include/support/all_perms.spt && echo > > > > > > > > > > true),true) > > > > > > > > > > +TARGETS+=test_notify.te > > > > > > > > > > +endif > > > > > > > > > > + > > > > > > > > > > ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) > > > > > > > > > > TARGETS:=$(filter-out test_overlayfs.te > > > > > > > > > > test_mqueue.te, $(TARGETS)) > > > > > > > > > > endif > > > > > > > > > > diff --git a/policy/test_notify.te b/policy/test_notify.te > > > > > > > > > > new file mode 100644 > > > > > > > > > > index 0000000..8ba6f1a > > > > > > > > > > --- /dev/null > > > > > > > > > > +++ b/policy/test_notify.te > > > > > > > > > > @@ -0,0 +1,74 @@ > > > > > > > > > > +#################################################### > > > > > > > > > > +# Policy for testing inoftify and fanotify watches # > > > > > > > > > > +#################################################### > > > > > > > > > > + > > > > > > > > > > +attribute test_notify_domain; > > > > > > > > > > + > > > > > > > > > > +# Type for the file on which we want to set a watch > > > > > > > > > > +type test_notify_file_t; > > > > > > > > > > +files_type(test_notify_file_t); > > > > > > > > > > + > > > > > > > > > > +# Domain for the process which CAN set a non-permission watch > > > > > > > > > > +type test_watch_t; > > > > > > > > > > +domain_type(test_watch_t); > > > > > > > > > > +unconfined_runs_test(test_watch_t); > > > > > > > > > > + > > > > > > > > > > +typeattribute test_watch_t test_notify_domain; > > > > > > > > > > +typeattribute test_watch_t testdomain; > > > > > > > > > > + > > > > > > > > > > +allow test_notify_domain self:capability sys_admin; > > > > > > > > > > + > > > > > > > > > > +allow test_watch_t test_notify_file_t:file { > > > > > > > > > > read write open watch }; > > > > > > > > > > + > > > > > > > > > > +# Domain for the process which CAN set a NON-access watch on a file > > > > > > > > > > +type test_perm_watch_t; > > > > > > > > > > +domain_type(test_perm_watch_t); > > > > > > > > > > +unconfined_runs_test(test_perm_watch_t); > > > > > > > > > > + > > > > > > > > > > +typeattribute test_perm_watch_t test_notify_domain; > > > > > > > > > > +typeattribute test_perm_watch_t testdomain; > > > > > > > > > > + > > > > > > > > > > +allow test_perm_watch_t test_notify_file_t:file > > > > > > > > > > { read write open watch watch_with_perm }; > > > > > > > > > > + > > > > > > > > > > +# Domain which CAN set a NON-perm watch which MAY read accesses > > > > > > > > > > +type test_read_watch_t; > > > > > > > > > > +domain_type(test_read_watch_t); > > > > > > > > > > +unconfined_runs_test(test_read_watch_t); > > > > > > > > > > + > > > > > > > > > > +typeattribute test_read_watch_t test_notify_domain; > > > > > > > > > > +typeattribute test_read_watch_t testdomain; > > > > > > > > > > + > > > > > > > > > > +allow test_read_watch_t test_notify_file_t:file > > > > > > > > > > { read write open watch watch_reads }; > > > > > > > > > > + > > > > > > > > > > +# Domain which CAN set any watch which CAN read accesses > > > > > > > > > > +type test_perm_read_watch_t; > > > > > > > > > > +domain_type(test_perm_read_watch_t); > > > > > > > > > > +unconfined_runs_test(test_perm_read_watch_t); > > > > > > > > > > + > > > > > > > > > > +typeattribute test_perm_read_watch_t test_notify_domain; > > > > > > > > > > +typeattribute test_perm_read_watch_t testdomain; > > > > > > > > > > + > > > > > > > > > > +allow test_perm_read_watch_t > > > > > > > > > > test_notify_file_t:file { read write open watch > > > > > > > > > > watch_with_perm watch_reads }; > > > > > > > > > > + > > > > > > > > > > +# Domain which CANNOT set any watches > > > > > > > > > > +type test_no_watch_t; > > > > > > > > > > +domain_type(test_no_watch_t); > > > > > > > > > > +unconfined_runs_test(test_no_watch_t); > > > > > > > > > > + > > > > > > > > > > +typeattribute test_no_watch_t test_notify_domain; > > > > > > > > > > +typeattribute test_no_watch_t testdomain; > > > > > > > > > > + > > > > > > > > > > +allow test_no_watch_t test_notify_file_t:file { read write open }; > > > > > > > > > > + > > > > > > > > > > +# Domain which has no write access but can watch > > > > > > > > > > +type test_rdonly_t; > > > > > > > > > > +domain_type(test_rdonly_t); > > > > > > > > > > +unconfined_runs_test(test_rdonly_t); > > > > > > > > > > + > > > > > > > > > > +typeattribute test_rdonly_t test_notify_domain; > > > > > > > > > > +typeattribute test_rdonly_t testdomain; > > > > > > > > > > + > > > > > > > > > > +allow test_rdonly_t test_notify_file_t:file { read open watch }; > > > > > > > > > > + > > > > > > > > > > +miscfiles_domain_entry_test_files(test_notify_domain); > > > > > > > > > > +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); > > > > > > > > > > diff --git a/tests/Makefile b/tests/Makefile > > > > > > > > > > index 63aa325..b99c96e 100644 > > > > > > > > > > --- a/tests/Makefile > > > > > > > > > > +++ b/tests/Makefile > > > > > > > > > > @@ -50,6 +50,10 @@ ifeq ($(shell grep > > > > > > > > > > "^SELINUX_INFINIBAND_PKEY_TEST=" > > > > > > > > > > infiniband_pkey/ibpkey_test. > > > > > > > > > > SUBDIRS += infiniband_pkey > > > > > > > > > > endif > > > > > > > > > > +ifeq ($(shell grep -q all_file_perms.*watch > > > > > > > > > > $(POLDEV)/include/support/all_perms.spt && echo > > > > > > > > > > true),true) > > > > > > > > > > +SUBDIRS+=notify > > > > > > > > > > +endif > > > > > > > > > > + > > > > > > > > > > ifeq ($(DISTRO),RHEL4) > > > > > > > > > > SUBDIRS:=$(filter-out bounds dyntrace > > > > > > > > > > dyntrans inet_socket mmap nnp_nosuid overlay > > > > > > > > > > unix_socket, $(SUBDIRS)) > > > > > > > > > > endif > > > > > > > > > > diff --git a/tests/notify/Makefile b/tests/notify/Makefile > > > > > > > > > > new file mode 100644 > > > > > > > > > > index 0000000..78c4b3b > > > > > > > > > > --- /dev/null > > > > > > > > > > +++ b/tests/notify/Makefile > > > > > > > > > > @@ -0,0 +1,5 @@ > > > > > > > > > > +TARGETS=test_inotify test_fanotify > > > > > > > > > > + > > > > > > > > > > +all: $(TARGETS) > > > > > > > > > > +clean: > > > > > > > > > > + rm -f $(TARGETS) > > > > > > > > > > diff --git a/tests/notify/test b/tests/notify/test > > > > > > > > > > new file mode 100755 > > > > > > > > > > index 0000000..21f03de > > > > > > > > > > --- /dev/null > > > > > > > > > > +++ b/tests/notify/test > > > > > > > > > > @@ -0,0 +1,101 @@ > > > > > > > > > > +#!/usr/bin/perl > > > > > > > > > > + > > > > > > > > > > +use Test; > > > > > > > > > > +BEGIN { plan tests => 14 } # number of tests to run > > > > > > > > > > + > > > > > > > > > > +# help the test script locate itself > > > > > > > > > > +$basedir = $0; > > > > > > > > > > +$basedir =~ s|(.*)/[^/]*|$1|; > > > > > > > > > > + > > > > > > > > > > +# Get rid of a testfile from last run if it's there (just in case) > > > > > > > > > > +system("rm -f $basedir/watch_me"); > > > > > > > > > > + > > > > > > > > > > +# Create a new test file > > > > > > > > > > +system("touch $basedir/watch_me"); > > > > > > > > > > +system("chcon -t test_notify_file_t $basedir/watch_me"); > > > > > > > > > > + > > > > > > > > > > +## TESTS > > > > > > > > > > + > > > > > > > > > > +## TEST BASIC WATCH PERMISSION > > > > > > > > > > +# Should be able to set inotify watch > > > > > > > > > > +$exit_val = > > > > > > > > > > + system("runcon -t test_watch_t > > > > > > > > > > $basedir/test_inotify $basedir/watch_me 2>&1"); > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > + > > > > > > > > > > +# Should be able to set non-permissions based fanotify watch > > > > > > > > > > +$exit_val = system( > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > $basedir/test_fanotify $basedir/watch_me 2>&1"); > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > + > > > > > > > > > > +# Should NOT be able to set permission based fanotify watch > > > > > > > > > > +$exit_val = system( > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > $basedir/test_fanotify -p $basedir/watch_me > > > > > > > > > > 2>&1"); > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > + > > > > > > > > > > +# Should NOT be able to set read based fanotify watch > > > > > > > > > > +$exit_val = system( > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > $basedir/test_fanotify -r $basedir/watch_me > > > > > > > > > > 2>&1"); > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > + > > > > > > > > > > +# Should NOT be able to set read based inotify watch > > > > > > > > > > +$exit_val = system( > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > $basedir/test_inotify -r $basedir/watch_me > > > > > > > > > > 2>&1"); > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > + > > > > > > > > > > +## TEST PERM WATCH > > > > > > > > > > +# Should be able to set permission based fanotify watch > > > > > > > > > > +$exit_val = system( > > > > > > > > > > +"runcon -t test_perm_watch_t > > > > > > > > > > $basedir/test_fanotify -p $basedir/watch_me > > > > > > > > > > 2>&1" > > > > > > > > > > +); > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > + > > > > > > > > > > +# Should NOT be able to set watch of accesses > > > > > > > > > > +$exit_val = system( > > > > > > > > > > +"runcon -t test_perm_watch_t > > > > > > > > > > $basedir/test_fanotify -r $basedir/watch_me > > > > > > > > > > 2>&1" > > > > > > > > > > +); > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > + > > > > > > > > > > +## TEST READ NO PERM WATCH PERMSISSIONS > > > > > > > > > > +# Should NOT be able to set read and perm watch > > > > > > > > > > +$exit_val = system( > > > > > > > > > > +"runcon -t test_read_watch_t > > > > > > > > > > $basedir/test_fanotify -p -r $basedir/watch_me > > > > > > > > > > 2>&1" > > > > > > > > > > +); > > > > > > > > > > +ok($exit_val); # should fail > > > > > > > > > > + > > > > > > > > > > +# Should be able to set read inotify watch > > > > > > > > > > +$exit_val = system( > > > > > > > > > > +"runcon -t test_read_watch_t > > > > > > > > > > $basedir/test_inotify -r $basedir/watch_me 2>&1" > > > > > > > > > > +); > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > + > > > > > > > > > > +## TEST READ WITH PERM WATCH PERMSISSIONS > > > > > > > > > > +# Should be able to set read and perm watch > > > > > > > > > > +$exit_val = system( > > > > > > > > > > +"runcon -t test_perm_read_watch_t > > > > > > > > > > $basedir/test_fanotify -p -r $basedir/watch_me > > > > > > > > > > 2>&1" > > > > > > > > > > +); > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > + > > > > > > > > > > +## TEST NO WATCH PERMSISSIONS > > > > > > > > > > +# Should NOT be able to set inotify watch > > > > > > > > > > +$exit_val = system( > > > > > > > > > > + "runcon -t test_no_watch_t > > > > > > > > > > $basedir/test_inotify $basedir/watch_me 2>&1"); > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > + > > > > > > > > > > +# Should NOT be able to set any fanotify watch > > > > > > > > > > +$exit_val = system( > > > > > > > > > > + "runcon -t test_no_watch_t > > > > > > > > > > $basedir/test_fanotify $basedir/watch_me 2>&1"); > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > + > > > > > > > > > > +## TEST READ ONLY > > > > > > > > > > +# Should NOT be able to get read-write descriptor > > > > > > > > > > +$exit_val = system( > > > > > > > > > > + "runcon -t test_rdonly_t > > > > > > > > > > $basedir/test_fanotify -l $basedir/watch_me > > > > > > > > > > 2>&1"); > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > + > > > > > > > > > > +# Should be able to get read-write descriptor > > > > > > > > > > +$exit_val = system( > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > $basedir/test_fanotify -l $basedir/watch_me > > > > > > > > > > 2>&1"); > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > + > > > > > > > > > > +# Clean up test file > > > > > > > > > > +system("rm -f $basedir/watch_me"); > > > > > > > > > > diff --git a/tests/notify/test_fanotify.c > > > > > > > > > > b/tests/notify/test_fanotify.c > > > > > > > > > > new file mode 100644 > > > > > > > > > > index 0000000..fff773f > > > > > > > > > > --- /dev/null > > > > > > > > > > +++ b/tests/notify/test_fanotify.c > > > > > > > > > > @@ -0,0 +1,105 @@ > > > > > > > > > > +#define _GNU_SOURCE 1 > > > > > > > > > > + > > > > > > > > > > +#include <stdio.h> > > > > > > > > > > +#include <stdlib.h> > > > > > > > > > > + > > > > > > > > > > +#include <getopt.h> > > > > > > > > > > + > > > > > > > > > > +#include <fcntl.h> > > > > > > > > > > +#include <poll.h> > > > > > > > > > > +#include <sys/fanotify.h> > > > > > > > > > > +#include <unistd.h> > > > > > > > > > > + > > > > > > > > > > +void printUsage() > > > > > > > > > > +{ > > > > > > > > > > + fprintf(stderr, "Usage: test_fanotify [-p] > > > > > > > > > > [-r] [-l] file_name\n"); > > > > > > > > > > + exit(1); > > > > > > > > > > +} > > > > > > > > > > + > > > > > > > > > > +int main(int argc, char *argv[]) > > > > > > > > > > +{ > > > > > > > > > > + if (argc < 2) { > > > > > > > > > > + printUsage(); > > > > > > > > > > + } > > > > > > > > > > + > > > > > > > > > > + int fd, ret, arg; > > > > > > > > > > + int mask = FAN_OPEN; // default mask > > > > > > > > > > + int listening = 0; > > > > > > > > > > + > > > > > > > > > > + // the -p flag will test for watch_with_perm > > > > > > > > > > + // the mask used at mark will contain FAN_OPEN_PERM > > > > > > > > > > + // > > > > > > > > > > + // the -r flag will test for watching > > > > > > > > > > accesses to files for reads > > > > > > > > > > + // the mask will contain FAN_ACCESS > > > > > > > > > > + while ((arg = getopt(argc, argv, "prl")) != -1) { > > > > > > > > > > + switch (arg) { > > > > > > > > > > + case 'p': > > > > > > > > > > + mask |= FAN_OPEN_PERM; > > > > > > > > > > + break; > > > > > > > > > > + case 'r': > > > > > > > > > > + mask |= FAN_ACCESS; > > > > > > > > > > + break; > > > > > > > > > > + case 'l': > > > > > > > > > > + listening = 1; > > > > > > > > > > + break; > > > > > > > > > > + default: > > > > > > > > > > + printUsage(); > > > > > > > > > > + } > > > > > > > > > > + } > > > > > > > > > > + > > > > > > > > > > + // get file descriptor for new fanotify event queue > > > > > > > > > > + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); > > > > > > > > > > + if (fd < 0) { > > > > > > > > > > + perror("fanotify_init:bad file descriptor"); > > > > > > > > > > + exit(1); > > > > > > > > > > + } > > > > > > > > > > + > > > > > > > > > > + // mark a filesystem object and add mark to event queue > > > > > > > > > > + // get notifications on file opens, accesses, and closes > > > > > > > > > > + // use current working directory as base dir > > > > > > > > > > + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, > > > > > > > > > > AT_FDCWD, argv[optind]); > > > > > > > > > > + > > > > > > > > > > + if (ret < 0) { > > > > > > > > > > + perror("test_fanotify:watch denied"); > > > > > > > > > > + exit(1); > > > > > > > > > > + } > > > > > > > > > > + > > > > > > > > > > + // logic to actually listen for an event if > > > > > > > > > > the -l flag is passed > > > > > > > > > > + // this is used to test if an app with > > > > > > > > > > read-only access can get a read/write > > > > > > > > > > + // handle to the watched file > > > > > > > > > > + if (listening) { > > > > > > > > > > + if (fork() == 0) { // fork a child > > > > > > > > > > process to cause an event on the file > > > > > > > > > > + FILE *f; > > > > > > > > > > + > > > > > > > > > > + f = fopen(argv[optind], "r"); // open file for reading > > > > > > > > > > + fgetc(f); // read char from file > > > > > > > > > > + > > > > > > > > > > + fclose(f); > > > > > > > > > > + } else { // logic to watch for events > > > > > > > > > > and try to access file read/write > > > > > > > > > > + struct pollfd fds; > > > > > > > > > > + fds.fd = fd; > > > > > > > > > > + fds.events = POLLIN; > > > > > > > > > > + > > > > > > > > > > + while (listening) { > > > > > > > > > > + int polled = poll(&fds, 1, 1); > > > > > > > > > > + if (polled > 0) { > > > > > > > > > > + if (fds.revents & POLLIN) { > > > > > > > > > > + struct fanotify_event_metadata buff[200]; > > > > > > > > > > + > > > > > > > > > > + size_t len = read(fd, > > > > > > > > > > (void *)&buff, sizeof(buff)); > > > > > > > > > > + if (len == -1) { > > > > > > > > > > + > > > > > > > > > > perror("test_fanotify:can't open file"); > > > > > > > > > > + exit(1); > > > > > > > > > > + } else { > > > > > > > > > > + listening = 0; > > > > > > > > > > + break; > > > > > > > > > > + } > > > > > > > > > > + } > > > > > > > > > > + } else if (polled == -1) { > > > > > > > > > > + listening = 0; > > > > > > > > > > + } > > > > > > > > > > + } > > > > > > > > > > + } > > > > > > > > > > + } > > > > > > > > > > + exit(0); > > > > > > > > > > +} > > > > > > > > > > diff --git a/tests/notify/test_inotify.c > > > > > > > > > > b/tests/notify/test_inotify.c > > > > > > > > > > new file mode 100644 > > > > > > > > > > index 0000000..17c3565 > > > > > > > > > > --- /dev/null > > > > > > > > > > +++ b/tests/notify/test_inotify.c > > > > > > > > > > @@ -0,0 +1,43 @@ > > > > > > > > > > +#include <stdio.h> > > > > > > > > > > +#include <stdlib.h> > > > > > > > > > > +#include <sys/inotify.h> > > > > > > > > > > +#include <getopt.h> > > > > > > > > > > + > > > > > > > > > > +int main(int argc, char *argv[]) > > > > > > > > > > +{ > > > > > > > > > > + if (argc < 2) { > > > > > > > > > > + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); > > > > > > > > > > + exit(1); > > > > > > > > > > + } > > > > > > > > > > + > > > > > > > > > > + int fd, wd, arg; > > > > > > > > > > + int mask = IN_MODIFY; > > > > > > > > > > + > > > > > > > > > > + while ((arg = getopt(argc, argv, "pr")) != -1) { > > > > > > > > > > + switch (arg) { > > > > > > > > > > + case 'r': > > > > > > > > > > + mask |= IN_ACCESS; > > > > > > > > > > + break; > > > > > > > > > > + default: > > > > > > > > > > + fprintf(stderr, "Usage: > > > > > > > > > > test_inotify [-r] file_name\n"); > > > > > > > > > > + exit(1); > > > > > > > > > > + } > > > > > > > > > > + } > > > > > > > > > > + > > > > > > > > > > + // get new file descriptor for inotify access > > > > > > > > > > + fd = inotify_init(); > > > > > > > > > > + if (fd < 0) { > > > > > > > > > > + perror("inotify_init:bad file descriptor"); > > > > > > > > > > + exit(1); > > > > > > > > > > + } > > > > > > > > > > + > > > > > > > > > > + // set watch on file and get watch > > > > > > > > > > descriptor for accessing events on it > > > > > > > > > > + wd = inotify_add_watch(fd, argv[optind], mask); > > > > > > > > > > + > > > > > > > > > > + if (wd < 0) { > > > > > > > > > > + perror("test_inotify:watch denied"); > > > > > > > > > > + exit(1); > > > > > > > > > > + } > > > > > > > > > > + > > > > > > > > > > + exit(0); > > > > > > > > > > +} > > > > > > > > > > -- > > > > > > > > > > 2.21.0 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
On 9/10/19 12:32 PM, Dominick Grift wrote: > On Tue, Sep 10, 2019 at 12:25:44PM -0400, Stephen Smalley wrote: >> On 9/10/19 11:22 AM, Dominick Grift wrote: >>> On Tue, Sep 10, 2019 at 11:02:16AM -0400, Stephen Smalley wrote: >>>> On 9/10/19 10:59 AM, Stephen Smalley wrote: >>>>> On 9/10/19 10:54 AM, Stephen Smalley wrote: >>>>>> On 9/10/19 10:40 AM, Stephen Smalley wrote: >>>>>>> On 9/10/19 10:15 AM, Dominick Grift wrote: >>>>>>>> On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: >>>>>>>>> On 9/10/19 1:59 AM, Dominick Grift wrote: >>>>>>>>>> On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: >>>>>>>>>>> Added a suite to test permissions for setting >>>>>>>>>>> inotify and fanotify watches >>>>>>>>>>> on filesystem objects. Tests watch, >>>>>>>>>>> watch_with_perm, and watch_reads permissions. >>>>>>>>>> >>>>>>>>>> Ive also "tested" the fsnotify patch. And my tests >>>>>>>>>> indicate that this might cause issues: >>>>>>>>>> >>>>>>>>>> I added the access vectors to my policy, but on >>>>>>>>>> older systems (debian 10) cron fails to start >>>>>>>>>> cron needs the "entrypoint" permission on >>>>>>>>>> /etc/crontab but it looks like appending the "watch" >>>>>>>>>> access vectors to common-file disrupted the ordering >>>>>>>>>> The result is that now i have to allow cron to >>>>>>>>>> "watch_read" /etc/crontab even though the neither >>>>>>>>>> kernel nor selinux user space are aware of the >>>>>>>>>> fsnotify access vectors >>>>>>>>>> It seems the cron selinux code got confused and now >>>>>>>>>> thinks watch_read is entrypoint (its using selinux >>>>>>>>>> code to determine whether it can manually transition >>>>>>>>>> to cronjob domains on crontabs) >>>>>>>>>> >>>>>>>>>> I am hoping this issue with resolve itself on >>>>>>>>>> systems with kernels and user spaces that suppose >>>>>>>>>> fsnotify. >>>>>>>>>> However unless i am overlooking something this is >>>>>>>>>> still likely to disrupt compatibility >>>>>>>>> >>>>>>>>> So, IIUC, the issue is that: >>>>>>>>> a) older cron was directly using the fixed >>>>>>>>> FILE__ENTRYPOINT definition from >>>>>>>>> libselinux in a security_compute_av() call rather than >>>>>>>>> dynamically looking >>>>>>>>> up entrypoint permission, >>>>>>>>> b) the value of the file entrypoint permission in policy >>>>>>>>> has changed because >>>>>>>>> you updated your policy and chose to place the watch* >>>>>>>>> permissions in the >>>>>>>>> common file definition to match the kernel. >>>>>>>>> >>>>>>>>> Note that you could have instead sprinkled copies of the >>>>>>>>> watch* permissions >>>>>>>>> across all of the individual file/dir/*_file classes and >>>>>>>>> placed them at the >>>>>>>>> end of the classes if you wanted to avoid this >>>>>>>>> compatibility issue. The >>>>>>>>> policy and kernel definitions no longer need to be >>>>>>>>> identical; the kernel >>>>>>>>> will dynamically map between them for its own permission checks. >>>>>>>>> >>>>>>>>> Also, this should have already been broken for you when >>>>>>>>> map permission was >>>>>>>>> added, which would have shown up as execute_no_trans >>>>>>>>> being checked instead >>>>>>>>> of entrypoint. This was already filed as a bug on cron >>>>>>>>> in debian here: >>>>>>>>> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 >>>>>>>>> >>>>>>>>> So, wrt compatibility, IIUC: >>>>>>>>> - the kernel change does not break compatibility for old policy + old >>>>>>>>> userspace, >>>>>>>>> - new policy can choose to add the new permissions in a >>>>>>>>> backward-compatible >>>>>>>>> manner if desired, although refpolicy has already chosen >>>>>>>>> not to do this for >>>>>>>>> map permission, >>>>>>>>> - the offending code in cron produces build warnings >>>>>>>>> that were introduced in >>>>>>>>> 2014 in libselinux to update their code to use the dynamic class/perm >>>>>>>>> mapping support, which would resolve the issue. >>>>>>>> >>>>>>>> this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d >>>>>>>> >>>>>>>> >>>>>>>> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x >>>>>>>> --common common_file >>>>>>>> >>>>>>>> Commons: 1 >>>>>>>> common common_file >>>>>>>> { >>>>>>>> append >>>>>>>> lock >>>>>>>> mounton >>>>>>>> unlink >>>>>>>> read >>>>>>>> create >>>>>>>> quotaon >>>>>>>> execute >>>>>>>> setattr >>>>>>>> map >>>>>>>> relabelto >>>>>>>> rename >>>>>>>> link >>>>>>>> ioctl >>>>>>>> getattr >>>>>>>> relabelfrom >>>>>>>> } >>>>>>>> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile >>>>>>>> >>>>>>>> Classes: 1 >>>>>>>> class file >>>>>>>> inherits common_file >>>>>>>> { >>>>>>>> execmod >>>>>>>> watch >>>>>>>> write >>>>>>>> watch_reads >>>>>>>> execute_no_trans >>>>>>>> watch_mount >>>>>>>> watch_with_perm >>>>>>>> open >>>>>>>> watch_sb >>>>>>>> audit_access >>>>>>>> entrypoint >>>>>>>> } >>>>>>> >>>>>>> If you want to preserve compatibility with userspace using fixed >>>>>>> definitions of FILE__ENTRYPOINT, then you have to insert any new >>>>>>> file permissions after the current entrypoint permission in the >>>>>>> class file. So watch and friends have to go after it, not before >>>>>>> it. >>>>>>> >>>>>>> Also, since the kernel always uses FILE__WATCH* in the check >>>>>>> code rather than distinguishing by class, the watch* permissions >>>>>>> need to be at the same offset in all of the file classes. The >>>>>>> same is true of the other file permissions. It looks like you >>>>>>> may have other permissions out of sync across the file classes >>>>>>> e.g. execmod, open, audit_access, that need to be aligned or the >>>>>>> kernel could check the wrong permission. >>>>>> >>>>>> Sorry, the last para isn't correct - it should get mapped correctly >>>>>> per class. But you do need to add the permissions after entrypoint >>>>>> in the file class to avoid displacing its value. >>>>> >>>>> Also, it looks like your file class permission order differs in other >>>>> incompatible ways. If you want it to be compatible with the deprecated >>>>> libselinux headers, the requisite order would be: >>>>> class file >>>>> inherits common_file >>>>> { >>>>> execute_no_trans >>>>> entrypoint >>>>> execmod >>>>> open >>>>> audit_access >>>>> map >>>> >>>> Sorry, insert watch* permissions here. >>> >>> I applied brute force: >>> >>> the map permission can be part of common_file just fine. >>> the audit_access av (which was clearly introduced after entrypoint can precede entrypoint just fine. >>> >>> The problem is the prescence of the fsnotify access vector in general. Moving them out of common_file and after entrypoint does not make a difference. >>> As soon as I remove the fsnotify av's things start to work. >>> >>> In other words. besides the precensce of the fsnotify access vectors everything (seemingly) is in order >>> Now for me the question remains: will this issue automatically resolve itself as soon as userspace and kernel support the fsnotify av >> >> That doesn't make any sense to me. Sounds like a bug somewhere. Anything >> that changes the permission bit value in the policy for FILE__ENTRYPOINT is >> going to break legacy crond that is using the hardcoded value from the >> deprecated libselinux headers. So adding permissions at the end of the file >> class should be fine. Adding or removing to/from common file should break. >> I can't explain the behavior you are seeing. > > It does not make sense to me either, but i believe it when i see it. > Ive tried several times and just removing the fsnotify access vectors make it work. Whether i append them to common_file or whether i append them to the individual classes does not make a difference. > > BTW: this fixes it for me: https://lore.kernel.org/selinux/d706a78c-d6d0-13bb-c9af-7ec4365b9b44@debian.org/T/#u I don't suppose you could make the broken policy available somewhere? Source and a binary. > >> >>>> >>>>> } >>>>> >>>>>> >>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> >>>>>>>>>>> --- >>>>>>>>>>> policy/Makefile | 4 ++ >>>>>>>>>>> policy/test_notify.te | 74 ++++++++++++++++++++++++ >>>>>>>>>>> tests/Makefile | 4 ++ >>>>>>>>>>> tests/notify/Makefile | 5 ++ >>>>>>>>>>> tests/notify/test | 101 >>>>>>>>>>> +++++++++++++++++++++++++++++++++ >>>>>>>>>>> tests/notify/test_fanotify.c | 105 >>>>>>>>>>> +++++++++++++++++++++++++++++++++++ >>>>>>>>>>> tests/notify/test_inotify.c | 43 ++++++++++++++ >>>>>>>>>>> 7 files changed, 336 insertions(+) >>>>>>>>>>> create mode 100644 policy/test_notify.te >>>>>>>>>>> create mode 100644 tests/notify/Makefile >>>>>>>>>>> create mode 100755 tests/notify/test >>>>>>>>>>> create mode 100644 tests/notify/test_fanotify.c >>>>>>>>>>> create mode 100644 tests/notify/test_inotify.c >>>>>>>>>>> >>>>>>>>>>> diff --git a/policy/Makefile b/policy/Makefile >>>>>>>>>>> index 305b572..65f88c5 100644 >>>>>>>>>>> --- a/policy/Makefile >>>>>>>>>>> +++ b/policy/Makefile >>>>>>>>>>> @@ -71,6 +71,10 @@ ifeq ($(shell grep -q >>>>>>>>>>> corenet_sctp_bind_all_nodes >>>>>>>>>>> $(POLDEV)/include/kernel/coren >>>>>>>>>>> TARGETS += test_sctp.te >>>>>>>>>>> endif >>>>>>>>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>>>>>>>> $(POLDEV)/include/support/all_perms.spt && echo >>>>>>>>>>> true),true) >>>>>>>>>>> +TARGETS+=test_notify.te >>>>>>>>>>> +endif >>>>>>>>>>> + >>>>>>>>>>> ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) >>>>>>>>>>> TARGETS:=$(filter-out test_overlayfs.te >>>>>>>>>>> test_mqueue.te, $(TARGETS)) >>>>>>>>>>> endif >>>>>>>>>>> diff --git a/policy/test_notify.te b/policy/test_notify.te >>>>>>>>>>> new file mode 100644 >>>>>>>>>>> index 0000000..8ba6f1a >>>>>>>>>>> --- /dev/null >>>>>>>>>>> +++ b/policy/test_notify.te >>>>>>>>>>> @@ -0,0 +1,74 @@ >>>>>>>>>>> +#################################################### >>>>>>>>>>> +# Policy for testing inoftify and fanotify watches # >>>>>>>>>>> +#################################################### >>>>>>>>>>> + >>>>>>>>>>> +attribute test_notify_domain; >>>>>>>>>>> + >>>>>>>>>>> +# Type for the file on which we want to set a watch >>>>>>>>>>> +type test_notify_file_t; >>>>>>>>>>> +files_type(test_notify_file_t); >>>>>>>>>>> + >>>>>>>>>>> +# Domain for the process which CAN set a non-permission watch >>>>>>>>>>> +type test_watch_t; >>>>>>>>>>> +domain_type(test_watch_t); >>>>>>>>>>> +unconfined_runs_test(test_watch_t); >>>>>>>>>>> + >>>>>>>>>>> +typeattribute test_watch_t test_notify_domain; >>>>>>>>>>> +typeattribute test_watch_t testdomain; >>>>>>>>>>> + >>>>>>>>>>> +allow test_notify_domain self:capability sys_admin; >>>>>>>>>>> + >>>>>>>>>>> +allow test_watch_t test_notify_file_t:file { >>>>>>>>>>> read write open watch }; >>>>>>>>>>> + >>>>>>>>>>> +# Domain for the process which CAN set a NON-access watch on a file >>>>>>>>>>> +type test_perm_watch_t; >>>>>>>>>>> +domain_type(test_perm_watch_t); >>>>>>>>>>> +unconfined_runs_test(test_perm_watch_t); >>>>>>>>>>> + >>>>>>>>>>> +typeattribute test_perm_watch_t test_notify_domain; >>>>>>>>>>> +typeattribute test_perm_watch_t testdomain; >>>>>>>>>>> + >>>>>>>>>>> +allow test_perm_watch_t test_notify_file_t:file >>>>>>>>>>> { read write open watch watch_with_perm }; >>>>>>>>>>> + >>>>>>>>>>> +# Domain which CAN set a NON-perm watch which MAY read accesses >>>>>>>>>>> +type test_read_watch_t; >>>>>>>>>>> +domain_type(test_read_watch_t); >>>>>>>>>>> +unconfined_runs_test(test_read_watch_t); >>>>>>>>>>> + >>>>>>>>>>> +typeattribute test_read_watch_t test_notify_domain; >>>>>>>>>>> +typeattribute test_read_watch_t testdomain; >>>>>>>>>>> + >>>>>>>>>>> +allow test_read_watch_t test_notify_file_t:file >>>>>>>>>>> { read write open watch watch_reads }; >>>>>>>>>>> + >>>>>>>>>>> +# Domain which CAN set any watch which CAN read accesses >>>>>>>>>>> +type test_perm_read_watch_t; >>>>>>>>>>> +domain_type(test_perm_read_watch_t); >>>>>>>>>>> +unconfined_runs_test(test_perm_read_watch_t); >>>>>>>>>>> + >>>>>>>>>>> +typeattribute test_perm_read_watch_t test_notify_domain; >>>>>>>>>>> +typeattribute test_perm_read_watch_t testdomain; >>>>>>>>>>> + >>>>>>>>>>> +allow test_perm_read_watch_t >>>>>>>>>>> test_notify_file_t:file { read write open watch >>>>>>>>>>> watch_with_perm watch_reads }; >>>>>>>>>>> + >>>>>>>>>>> +# Domain which CANNOT set any watches >>>>>>>>>>> +type test_no_watch_t; >>>>>>>>>>> +domain_type(test_no_watch_t); >>>>>>>>>>> +unconfined_runs_test(test_no_watch_t); >>>>>>>>>>> + >>>>>>>>>>> +typeattribute test_no_watch_t test_notify_domain; >>>>>>>>>>> +typeattribute test_no_watch_t testdomain; >>>>>>>>>>> + >>>>>>>>>>> +allow test_no_watch_t test_notify_file_t:file { read write open }; >>>>>>>>>>> + >>>>>>>>>>> +# Domain which has no write access but can watch >>>>>>>>>>> +type test_rdonly_t; >>>>>>>>>>> +domain_type(test_rdonly_t); >>>>>>>>>>> +unconfined_runs_test(test_rdonly_t); >>>>>>>>>>> + >>>>>>>>>>> +typeattribute test_rdonly_t test_notify_domain; >>>>>>>>>>> +typeattribute test_rdonly_t testdomain; >>>>>>>>>>> + >>>>>>>>>>> +allow test_rdonly_t test_notify_file_t:file { read open watch }; >>>>>>>>>>> + >>>>>>>>>>> +miscfiles_domain_entry_test_files(test_notify_domain); >>>>>>>>>>> +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); >>>>>>>>>>> diff --git a/tests/Makefile b/tests/Makefile >>>>>>>>>>> index 63aa325..b99c96e 100644 >>>>>>>>>>> --- a/tests/Makefile >>>>>>>>>>> +++ b/tests/Makefile >>>>>>>>>>> @@ -50,6 +50,10 @@ ifeq ($(shell grep >>>>>>>>>>> "^SELINUX_INFINIBAND_PKEY_TEST=" >>>>>>>>>>> infiniband_pkey/ibpkey_test. >>>>>>>>>>> SUBDIRS += infiniband_pkey >>>>>>>>>>> endif >>>>>>>>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>>>>>>>> $(POLDEV)/include/support/all_perms.spt && echo >>>>>>>>>>> true),true) >>>>>>>>>>> +SUBDIRS+=notify >>>>>>>>>>> +endif >>>>>>>>>>> + >>>>>>>>>>> ifeq ($(DISTRO),RHEL4) >>>>>>>>>>> SUBDIRS:=$(filter-out bounds dyntrace >>>>>>>>>>> dyntrans inet_socket mmap nnp_nosuid overlay >>>>>>>>>>> unix_socket, $(SUBDIRS)) >>>>>>>>>>> endif >>>>>>>>>>> diff --git a/tests/notify/Makefile b/tests/notify/Makefile >>>>>>>>>>> new file mode 100644 >>>>>>>>>>> index 0000000..78c4b3b >>>>>>>>>>> --- /dev/null >>>>>>>>>>> +++ b/tests/notify/Makefile >>>>>>>>>>> @@ -0,0 +1,5 @@ >>>>>>>>>>> +TARGETS=test_inotify test_fanotify >>>>>>>>>>> + >>>>>>>>>>> +all: $(TARGETS) >>>>>>>>>>> +clean: >>>>>>>>>>> + rm -f $(TARGETS) >>>>>>>>>>> diff --git a/tests/notify/test b/tests/notify/test >>>>>>>>>>> new file mode 100755 >>>>>>>>>>> index 0000000..21f03de >>>>>>>>>>> --- /dev/null >>>>>>>>>>> +++ b/tests/notify/test >>>>>>>>>>> @@ -0,0 +1,101 @@ >>>>>>>>>>> +#!/usr/bin/perl >>>>>>>>>>> + >>>>>>>>>>> +use Test; >>>>>>>>>>> +BEGIN { plan tests => 14 } # number of tests to run >>>>>>>>>>> + >>>>>>>>>>> +# help the test script locate itself >>>>>>>>>>> +$basedir = $0; >>>>>>>>>>> +$basedir =~ s|(.*)/[^/]*|$1|; >>>>>>>>>>> + >>>>>>>>>>> +# Get rid of a testfile from last run if it's there (just in case) >>>>>>>>>>> +system("rm -f $basedir/watch_me"); >>>>>>>>>>> + >>>>>>>>>>> +# Create a new test file >>>>>>>>>>> +system("touch $basedir/watch_me"); >>>>>>>>>>> +system("chcon -t test_notify_file_t $basedir/watch_me"); >>>>>>>>>>> + >>>>>>>>>>> +## TESTS >>>>>>>>>>> + >>>>>>>>>>> +## TEST BASIC WATCH PERMISSION >>>>>>>>>>> +# Should be able to set inotify watch >>>>>>>>>>> +$exit_val = >>>>>>>>>>> + system("runcon -t test_watch_t >>>>>>>>>>> $basedir/test_inotify $basedir/watch_me 2>&1"); >>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>> + >>>>>>>>>>> +# Should be able to set non-permissions based fanotify watch >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>> $basedir/test_fanotify $basedir/watch_me 2>&1"); >>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>> + >>>>>>>>>>> +# Should NOT be able to set permission based fanotify watch >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>> $basedir/test_fanotify -p $basedir/watch_me >>>>>>>>>>> 2>&1"); >>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>> + >>>>>>>>>>> +# Should NOT be able to set read based fanotify watch >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>> $basedir/test_fanotify -r $basedir/watch_me >>>>>>>>>>> 2>&1"); >>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>> + >>>>>>>>>>> +# Should NOT be able to set read based inotify watch >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>> $basedir/test_inotify -r $basedir/watch_me >>>>>>>>>>> 2>&1"); >>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>> + >>>>>>>>>>> +## TEST PERM WATCH >>>>>>>>>>> +# Should be able to set permission based fanotify watch >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> +"runcon -t test_perm_watch_t >>>>>>>>>>> $basedir/test_fanotify -p $basedir/watch_me >>>>>>>>>>> 2>&1" >>>>>>>>>>> +); >>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>> + >>>>>>>>>>> +# Should NOT be able to set watch of accesses >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> +"runcon -t test_perm_watch_t >>>>>>>>>>> $basedir/test_fanotify -r $basedir/watch_me >>>>>>>>>>> 2>&1" >>>>>>>>>>> +); >>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>> + >>>>>>>>>>> +## TEST READ NO PERM WATCH PERMSISSIONS >>>>>>>>>>> +# Should NOT be able to set read and perm watch >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> +"runcon -t test_read_watch_t >>>>>>>>>>> $basedir/test_fanotify -p -r $basedir/watch_me >>>>>>>>>>> 2>&1" >>>>>>>>>>> +); >>>>>>>>>>> +ok($exit_val); # should fail >>>>>>>>>>> + >>>>>>>>>>> +# Should be able to set read inotify watch >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> +"runcon -t test_read_watch_t >>>>>>>>>>> $basedir/test_inotify -r $basedir/watch_me 2>&1" >>>>>>>>>>> +); >>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>> + >>>>>>>>>>> +## TEST READ WITH PERM WATCH PERMSISSIONS >>>>>>>>>>> +# Should be able to set read and perm watch >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> +"runcon -t test_perm_read_watch_t >>>>>>>>>>> $basedir/test_fanotify -p -r $basedir/watch_me >>>>>>>>>>> 2>&1" >>>>>>>>>>> +); >>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>> + >>>>>>>>>>> +## TEST NO WATCH PERMSISSIONS >>>>>>>>>>> +# Should NOT be able to set inotify watch >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> + "runcon -t test_no_watch_t >>>>>>>>>>> $basedir/test_inotify $basedir/watch_me 2>&1"); >>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>> + >>>>>>>>>>> +# Should NOT be able to set any fanotify watch >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> + "runcon -t test_no_watch_t >>>>>>>>>>> $basedir/test_fanotify $basedir/watch_me 2>&1"); >>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>> + >>>>>>>>>>> +## TEST READ ONLY >>>>>>>>>>> +# Should NOT be able to get read-write descriptor >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> + "runcon -t test_rdonly_t >>>>>>>>>>> $basedir/test_fanotify -l $basedir/watch_me >>>>>>>>>>> 2>&1"); >>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>> + >>>>>>>>>>> +# Should be able to get read-write descriptor >>>>>>>>>>> +$exit_val = system( >>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>> $basedir/test_fanotify -l $basedir/watch_me >>>>>>>>>>> 2>&1"); >>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>> + >>>>>>>>>>> +# Clean up test file >>>>>>>>>>> +system("rm -f $basedir/watch_me"); >>>>>>>>>>> diff --git a/tests/notify/test_fanotify.c >>>>>>>>>>> b/tests/notify/test_fanotify.c >>>>>>>>>>> new file mode 100644 >>>>>>>>>>> index 0000000..fff773f >>>>>>>>>>> --- /dev/null >>>>>>>>>>> +++ b/tests/notify/test_fanotify.c >>>>>>>>>>> @@ -0,0 +1,105 @@ >>>>>>>>>>> +#define _GNU_SOURCE 1 >>>>>>>>>>> + >>>>>>>>>>> +#include <stdio.h> >>>>>>>>>>> +#include <stdlib.h> >>>>>>>>>>> + >>>>>>>>>>> +#include <getopt.h> >>>>>>>>>>> + >>>>>>>>>>> +#include <fcntl.h> >>>>>>>>>>> +#include <poll.h> >>>>>>>>>>> +#include <sys/fanotify.h> >>>>>>>>>>> +#include <unistd.h> >>>>>>>>>>> + >>>>>>>>>>> +void printUsage() >>>>>>>>>>> +{ >>>>>>>>>>> + fprintf(stderr, "Usage: test_fanotify [-p] >>>>>>>>>>> [-r] [-l] file_name\n"); >>>>>>>>>>> + exit(1); >>>>>>>>>>> +} >>>>>>>>>>> + >>>>>>>>>>> +int main(int argc, char *argv[]) >>>>>>>>>>> +{ >>>>>>>>>>> + if (argc < 2) { >>>>>>>>>>> + printUsage(); >>>>>>>>>>> + } >>>>>>>>>>> + >>>>>>>>>>> + int fd, ret, arg; >>>>>>>>>>> + int mask = FAN_OPEN; // default mask >>>>>>>>>>> + int listening = 0; >>>>>>>>>>> + >>>>>>>>>>> + // the -p flag will test for watch_with_perm >>>>>>>>>>> + // the mask used at mark will contain FAN_OPEN_PERM >>>>>>>>>>> + // >>>>>>>>>>> + // the -r flag will test for watching >>>>>>>>>>> accesses to files for reads >>>>>>>>>>> + // the mask will contain FAN_ACCESS >>>>>>>>>>> + while ((arg = getopt(argc, argv, "prl")) != -1) { >>>>>>>>>>> + switch (arg) { >>>>>>>>>>> + case 'p': >>>>>>>>>>> + mask |= FAN_OPEN_PERM; >>>>>>>>>>> + break; >>>>>>>>>>> + case 'r': >>>>>>>>>>> + mask |= FAN_ACCESS; >>>>>>>>>>> + break; >>>>>>>>>>> + case 'l': >>>>>>>>>>> + listening = 1; >>>>>>>>>>> + break; >>>>>>>>>>> + default: >>>>>>>>>>> + printUsage(); >>>>>>>>>>> + } >>>>>>>>>>> + } >>>>>>>>>>> + >>>>>>>>>>> + // get file descriptor for new fanotify event queue >>>>>>>>>>> + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); >>>>>>>>>>> + if (fd < 0) { >>>>>>>>>>> + perror("fanotify_init:bad file descriptor"); >>>>>>>>>>> + exit(1); >>>>>>>>>>> + } >>>>>>>>>>> + >>>>>>>>>>> + // mark a filesystem object and add mark to event queue >>>>>>>>>>> + // get notifications on file opens, accesses, and closes >>>>>>>>>>> + // use current working directory as base dir >>>>>>>>>>> + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, >>>>>>>>>>> AT_FDCWD, argv[optind]); >>>>>>>>>>> + >>>>>>>>>>> + if (ret < 0) { >>>>>>>>>>> + perror("test_fanotify:watch denied"); >>>>>>>>>>> + exit(1); >>>>>>>>>>> + } >>>>>>>>>>> + >>>>>>>>>>> + // logic to actually listen for an event if >>>>>>>>>>> the -l flag is passed >>>>>>>>>>> + // this is used to test if an app with >>>>>>>>>>> read-only access can get a read/write >>>>>>>>>>> + // handle to the watched file >>>>>>>>>>> + if (listening) { >>>>>>>>>>> + if (fork() == 0) { // fork a child >>>>>>>>>>> process to cause an event on the file >>>>>>>>>>> + FILE *f; >>>>>>>>>>> + >>>>>>>>>>> + f = fopen(argv[optind], "r"); // open file for reading >>>>>>>>>>> + fgetc(f); // read char from file >>>>>>>>>>> + >>>>>>>>>>> + fclose(f); >>>>>>>>>>> + } else { // logic to watch for events >>>>>>>>>>> and try to access file read/write >>>>>>>>>>> + struct pollfd fds; >>>>>>>>>>> + fds.fd = fd; >>>>>>>>>>> + fds.events = POLLIN; >>>>>>>>>>> + >>>>>>>>>>> + while (listening) { >>>>>>>>>>> + int polled = poll(&fds, 1, 1); >>>>>>>>>>> + if (polled > 0) { >>>>>>>>>>> + if (fds.revents & POLLIN) { >>>>>>>>>>> + struct fanotify_event_metadata buff[200]; >>>>>>>>>>> + >>>>>>>>>>> + size_t len = read(fd, >>>>>>>>>>> (void *)&buff, sizeof(buff)); >>>>>>>>>>> + if (len == -1) { >>>>>>>>>>> + >>>>>>>>>>> perror("test_fanotify:can't open file"); >>>>>>>>>>> + exit(1); >>>>>>>>>>> + } else { >>>>>>>>>>> + listening = 0; >>>>>>>>>>> + break; >>>>>>>>>>> + } >>>>>>>>>>> + } >>>>>>>>>>> + } else if (polled == -1) { >>>>>>>>>>> + listening = 0; >>>>>>>>>>> + } >>>>>>>>>>> + } >>>>>>>>>>> + } >>>>>>>>>>> + } >>>>>>>>>>> + exit(0); >>>>>>>>>>> +} >>>>>>>>>>> diff --git a/tests/notify/test_inotify.c >>>>>>>>>>> b/tests/notify/test_inotify.c >>>>>>>>>>> new file mode 100644 >>>>>>>>>>> index 0000000..17c3565 >>>>>>>>>>> --- /dev/null >>>>>>>>>>> +++ b/tests/notify/test_inotify.c >>>>>>>>>>> @@ -0,0 +1,43 @@ >>>>>>>>>>> +#include <stdio.h> >>>>>>>>>>> +#include <stdlib.h> >>>>>>>>>>> +#include <sys/inotify.h> >>>>>>>>>>> +#include <getopt.h> >>>>>>>>>>> + >>>>>>>>>>> +int main(int argc, char *argv[]) >>>>>>>>>>> +{ >>>>>>>>>>> + if (argc < 2) { >>>>>>>>>>> + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); >>>>>>>>>>> + exit(1); >>>>>>>>>>> + } >>>>>>>>>>> + >>>>>>>>>>> + int fd, wd, arg; >>>>>>>>>>> + int mask = IN_MODIFY; >>>>>>>>>>> + >>>>>>>>>>> + while ((arg = getopt(argc, argv, "pr")) != -1) { >>>>>>>>>>> + switch (arg) { >>>>>>>>>>> + case 'r': >>>>>>>>>>> + mask |= IN_ACCESS; >>>>>>>>>>> + break; >>>>>>>>>>> + default: >>>>>>>>>>> + fprintf(stderr, "Usage: >>>>>>>>>>> test_inotify [-r] file_name\n"); >>>>>>>>>>> + exit(1); >>>>>>>>>>> + } >>>>>>>>>>> + } >>>>>>>>>>> + >>>>>>>>>>> + // get new file descriptor for inotify access >>>>>>>>>>> + fd = inotify_init(); >>>>>>>>>>> + if (fd < 0) { >>>>>>>>>>> + perror("inotify_init:bad file descriptor"); >>>>>>>>>>> + exit(1); >>>>>>>>>>> + } >>>>>>>>>>> + >>>>>>>>>>> + // set watch on file and get watch >>>>>>>>>>> descriptor for accessing events on it >>>>>>>>>>> + wd = inotify_add_watch(fd, argv[optind], mask); >>>>>>>>>>> + >>>>>>>>>>> + if (wd < 0) { >>>>>>>>>>> + perror("test_inotify:watch denied"); >>>>>>>>>>> + exit(1); >>>>>>>>>>> + } >>>>>>>>>>> + >>>>>>>>>>> + exit(0); >>>>>>>>>>> +} >>>>>>>>>>> -- >>>>>>>>>>> 2.21.0 >>>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> >
On Tue, Sep 10, 2019 at 02:13:07PM -0400, Stephen Smalley wrote: > On 9/10/19 12:32 PM, Dominick Grift wrote: > > On Tue, Sep 10, 2019 at 12:25:44PM -0400, Stephen Smalley wrote: > > > On 9/10/19 11:22 AM, Dominick Grift wrote: > > > > On Tue, Sep 10, 2019 at 11:02:16AM -0400, Stephen Smalley wrote: > > > > > On 9/10/19 10:59 AM, Stephen Smalley wrote: > > > > > > On 9/10/19 10:54 AM, Stephen Smalley wrote: > > > > > > > On 9/10/19 10:40 AM, Stephen Smalley wrote: > > > > > > > > On 9/10/19 10:15 AM, Dominick Grift wrote: > > > > > > > > > On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: > > > > > > > > > > On 9/10/19 1:59 AM, Dominick Grift wrote: > > > > > > > > > > > On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: > > > > > > > > > > > > Added a suite to test permissions for setting > > > > > > > > > > > > inotify and fanotify watches > > > > > > > > > > > > on filesystem objects. Tests watch, > > > > > > > > > > > > watch_with_perm, and watch_reads permissions. > > > > > > > > > > > > > > > > > > > > > > Ive also "tested" the fsnotify patch. And my tests > > > > > > > > > > > indicate that this might cause issues: > > > > > > > > > > > > > > > > > > > > > > I added the access vectors to my policy, but on > > > > > > > > > > > older systems (debian 10) cron fails to start > > > > > > > > > > > cron needs the "entrypoint" permission on > > > > > > > > > > > /etc/crontab but it looks like appending the "watch" > > > > > > > > > > > access vectors to common-file disrupted the ordering > > > > > > > > > > > The result is that now i have to allow cron to > > > > > > > > > > > "watch_read" /etc/crontab even though the neither > > > > > > > > > > > kernel nor selinux user space are aware of the > > > > > > > > > > > fsnotify access vectors > > > > > > > > > > > It seems the cron selinux code got confused and now > > > > > > > > > > > thinks watch_read is entrypoint (its using selinux > > > > > > > > > > > code to determine whether it can manually transition > > > > > > > > > > > to cronjob domains on crontabs) > > > > > > > > > > > > > > > > > > > > > > I am hoping this issue with resolve itself on > > > > > > > > > > > systems with kernels and user spaces that suppose > > > > > > > > > > > fsnotify. > > > > > > > > > > > However unless i am overlooking something this is > > > > > > > > > > > still likely to disrupt compatibility > > > > > > > > > > > > > > > > > > > > So, IIUC, the issue is that: > > > > > > > > > > a) older cron was directly using the fixed > > > > > > > > > > FILE__ENTRYPOINT definition from > > > > > > > > > > libselinux in a security_compute_av() call rather than > > > > > > > > > > dynamically looking > > > > > > > > > > up entrypoint permission, > > > > > > > > > > b) the value of the file entrypoint permission in policy > > > > > > > > > > has changed because > > > > > > > > > > you updated your policy and chose to place the watch* > > > > > > > > > > permissions in the > > > > > > > > > > common file definition to match the kernel. > > > > > > > > > > > > > > > > > > > > Note that you could have instead sprinkled copies of the > > > > > > > > > > watch* permissions > > > > > > > > > > across all of the individual file/dir/*_file classes and > > > > > > > > > > placed them at the > > > > > > > > > > end of the classes if you wanted to avoid this > > > > > > > > > > compatibility issue. The > > > > > > > > > > policy and kernel definitions no longer need to be > > > > > > > > > > identical; the kernel > > > > > > > > > > will dynamically map between them for its own permission checks. > > > > > > > > > > > > > > > > > > > > Also, this should have already been broken for you when > > > > > > > > > > map permission was > > > > > > > > > > added, which would have shown up as execute_no_trans > > > > > > > > > > being checked instead > > > > > > > > > > of entrypoint. This was already filed as a bug on cron > > > > > > > > > > in debian here: > > > > > > > > > > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 > > > > > > > > > > > > > > > > > > > > So, wrt compatibility, IIUC: > > > > > > > > > > - the kernel change does not break compatibility for old policy + old > > > > > > > > > > userspace, > > > > > > > > > > - new policy can choose to add the new permissions in a > > > > > > > > > > backward-compatible > > > > > > > > > > manner if desired, although refpolicy has already chosen > > > > > > > > > > not to do this for > > > > > > > > > > map permission, > > > > > > > > > > - the offending code in cron produces build warnings > > > > > > > > > > that were introduced in > > > > > > > > > > 2014 in libselinux to update their code to use the dynamic class/perm > > > > > > > > > > mapping support, which would resolve the issue. > > > > > > > > > > > > > > > > > > this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d > > > > > > > > > > > > > > > > > > > > > > > > > > > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x > > > > > > > > > --common common_file > > > > > > > > > > > > > > > > > > Commons: 1 > > > > > > > > > common common_file > > > > > > > > > { > > > > > > > > > append > > > > > > > > > lock > > > > > > > > > mounton > > > > > > > > > unlink > > > > > > > > > read > > > > > > > > > create > > > > > > > > > quotaon > > > > > > > > > execute > > > > > > > > > setattr > > > > > > > > > map > > > > > > > > > relabelto > > > > > > > > > rename > > > > > > > > > link > > > > > > > > > ioctl > > > > > > > > > getattr > > > > > > > > > relabelfrom > > > > > > > > > } > > > > > > > > > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile > > > > > > > > > > > > > > > > > > Classes: 1 > > > > > > > > > class file > > > > > > > > > inherits common_file > > > > > > > > > { > > > > > > > > > execmod > > > > > > > > > watch > > > > > > > > > write > > > > > > > > > watch_reads > > > > > > > > > execute_no_trans > > > > > > > > > watch_mount > > > > > > > > > watch_with_perm > > > > > > > > > open > > > > > > > > > watch_sb > > > > > > > > > audit_access > > > > > > > > > entrypoint > > > > > > > > > } > > > > > > > > > > > > > > > > If you want to preserve compatibility with userspace using fixed > > > > > > > > definitions of FILE__ENTRYPOINT, then you have to insert any new > > > > > > > > file permissions after the current entrypoint permission in the > > > > > > > > class file. So watch and friends have to go after it, not before > > > > > > > > it. > > > > > > > > > > > > > > > > Also, since the kernel always uses FILE__WATCH* in the check > > > > > > > > code rather than distinguishing by class, the watch* permissions > > > > > > > > need to be at the same offset in all of the file classes. The > > > > > > > > same is true of the other file permissions. It looks like you > > > > > > > > may have other permissions out of sync across the file classes > > > > > > > > e.g. execmod, open, audit_access, that need to be aligned or the > > > > > > > > kernel could check the wrong permission. > > > > > > > > > > > > > > Sorry, the last para isn't correct - it should get mapped correctly > > > > > > > per class. But you do need to add the permissions after entrypoint > > > > > > > in the file class to avoid displacing its value. > > > > > > > > > > > > Also, it looks like your file class permission order differs in other > > > > > > incompatible ways. If you want it to be compatible with the deprecated > > > > > > libselinux headers, the requisite order would be: > > > > > > class file > > > > > > inherits common_file > > > > > > { > > > > > > execute_no_trans > > > > > > entrypoint > > > > > > execmod > > > > > > open > > > > > > audit_access > > > > > > map > > > > > > > > > > Sorry, insert watch* permissions here. > > > > > > > > I applied brute force: > > > > > > > > the map permission can be part of common_file just fine. > > > > the audit_access av (which was clearly introduced after entrypoint can precede entrypoint just fine. > > > > > > > > The problem is the prescence of the fsnotify access vector in general. Moving them out of common_file and after entrypoint does not make a difference. > > > > As soon as I remove the fsnotify av's things start to work. > > > > > > > > In other words. besides the precensce of the fsnotify access vectors everything (seemingly) is in order > > > > Now for me the question remains: will this issue automatically resolve itself as soon as userspace and kernel support the fsnotify av > > > > > > That doesn't make any sense to me. Sounds like a bug somewhere. Anything > > > that changes the permission bit value in the policy for FILE__ENTRYPOINT is > > > going to break legacy crond that is using the hardcoded value from the > > > deprecated libselinux headers. So adding permissions at the end of the file > > > class should be fine. Adding or removing to/from common file should break. > > > I can't explain the behavior you are seeing. > > > > It does not make sense to me either, but i believe it when i see it. > > Ive tried several times and just removing the fsnotify access vectors make it work. Whether i append them to common_file or whether i append them to the individual classes does not make a difference. > > > > BTW: this fixes it for me: https://lore.kernel.org/selinux/d706a78c-d6d0-13bb-c9af-7ec4365b9b44@debian.org/T/#u > > I don't suppose you could make the broken policy available somewhere? Source > and a binary. huh? git clone git://defensec.nl/dssp2.git && cd dssp2 && make all > > > > > > > > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> > > > > > > > > > > > > --- > > > > > > > > > > > > policy/Makefile | 4 ++ > > > > > > > > > > > > policy/test_notify.te | 74 ++++++++++++++++++++++++ > > > > > > > > > > > > tests/Makefile | 4 ++ > > > > > > > > > > > > tests/notify/Makefile | 5 ++ > > > > > > > > > > > > tests/notify/test | 101 > > > > > > > > > > > > +++++++++++++++++++++++++++++++++ > > > > > > > > > > > > tests/notify/test_fanotify.c | 105 > > > > > > > > > > > > +++++++++++++++++++++++++++++++++++ > > > > > > > > > > > > tests/notify/test_inotify.c | 43 ++++++++++++++ > > > > > > > > > > > > 7 files changed, 336 insertions(+) > > > > > > > > > > > > create mode 100644 policy/test_notify.te > > > > > > > > > > > > create mode 100644 tests/notify/Makefile > > > > > > > > > > > > create mode 100755 tests/notify/test > > > > > > > > > > > > create mode 100644 tests/notify/test_fanotify.c > > > > > > > > > > > > create mode 100644 tests/notify/test_inotify.c > > > > > > > > > > > > > > > > > > > > > > > > diff --git a/policy/Makefile b/policy/Makefile > > > > > > > > > > > > index 305b572..65f88c5 100644 > > > > > > > > > > > > --- a/policy/Makefile > > > > > > > > > > > > +++ b/policy/Makefile > > > > > > > > > > > > @@ -71,6 +71,10 @@ ifeq ($(shell grep -q > > > > > > > > > > > > corenet_sctp_bind_all_nodes > > > > > > > > > > > > $(POLDEV)/include/kernel/coren > > > > > > > > > > > > TARGETS += test_sctp.te > > > > > > > > > > > > endif > > > > > > > > > > > > +ifeq ($(shell grep -q all_file_perms.*watch > > > > > > > > > > > > $(POLDEV)/include/support/all_perms.spt && echo > > > > > > > > > > > > true),true) > > > > > > > > > > > > +TARGETS+=test_notify.te > > > > > > > > > > > > +endif > > > > > > > > > > > > + > > > > > > > > > > > > ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) > > > > > > > > > > > > TARGETS:=$(filter-out test_overlayfs.te > > > > > > > > > > > > test_mqueue.te, $(TARGETS)) > > > > > > > > > > > > endif > > > > > > > > > > > > diff --git a/policy/test_notify.te b/policy/test_notify.te > > > > > > > > > > > > new file mode 100644 > > > > > > > > > > > > index 0000000..8ba6f1a > > > > > > > > > > > > --- /dev/null > > > > > > > > > > > > +++ b/policy/test_notify.te > > > > > > > > > > > > @@ -0,0 +1,74 @@ > > > > > > > > > > > > +#################################################### > > > > > > > > > > > > +# Policy for testing inoftify and fanotify watches # > > > > > > > > > > > > +#################################################### > > > > > > > > > > > > + > > > > > > > > > > > > +attribute test_notify_domain; > > > > > > > > > > > > + > > > > > > > > > > > > +# Type for the file on which we want to set a watch > > > > > > > > > > > > +type test_notify_file_t; > > > > > > > > > > > > +files_type(test_notify_file_t); > > > > > > > > > > > > + > > > > > > > > > > > > +# Domain for the process which CAN set a non-permission watch > > > > > > > > > > > > +type test_watch_t; > > > > > > > > > > > > +domain_type(test_watch_t); > > > > > > > > > > > > +unconfined_runs_test(test_watch_t); > > > > > > > > > > > > + > > > > > > > > > > > > +typeattribute test_watch_t test_notify_domain; > > > > > > > > > > > > +typeattribute test_watch_t testdomain; > > > > > > > > > > > > + > > > > > > > > > > > > +allow test_notify_domain self:capability sys_admin; > > > > > > > > > > > > + > > > > > > > > > > > > +allow test_watch_t test_notify_file_t:file { > > > > > > > > > > > > read write open watch }; > > > > > > > > > > > > + > > > > > > > > > > > > +# Domain for the process which CAN set a NON-access watch on a file > > > > > > > > > > > > +type test_perm_watch_t; > > > > > > > > > > > > +domain_type(test_perm_watch_t); > > > > > > > > > > > > +unconfined_runs_test(test_perm_watch_t); > > > > > > > > > > > > + > > > > > > > > > > > > +typeattribute test_perm_watch_t test_notify_domain; > > > > > > > > > > > > +typeattribute test_perm_watch_t testdomain; > > > > > > > > > > > > + > > > > > > > > > > > > +allow test_perm_watch_t test_notify_file_t:file > > > > > > > > > > > > { read write open watch watch_with_perm }; > > > > > > > > > > > > + > > > > > > > > > > > > +# Domain which CAN set a NON-perm watch which MAY read accesses > > > > > > > > > > > > +type test_read_watch_t; > > > > > > > > > > > > +domain_type(test_read_watch_t); > > > > > > > > > > > > +unconfined_runs_test(test_read_watch_t); > > > > > > > > > > > > + > > > > > > > > > > > > +typeattribute test_read_watch_t test_notify_domain; > > > > > > > > > > > > +typeattribute test_read_watch_t testdomain; > > > > > > > > > > > > + > > > > > > > > > > > > +allow test_read_watch_t test_notify_file_t:file > > > > > > > > > > > > { read write open watch watch_reads }; > > > > > > > > > > > > + > > > > > > > > > > > > +# Domain which CAN set any watch which CAN read accesses > > > > > > > > > > > > +type test_perm_read_watch_t; > > > > > > > > > > > > +domain_type(test_perm_read_watch_t); > > > > > > > > > > > > +unconfined_runs_test(test_perm_read_watch_t); > > > > > > > > > > > > + > > > > > > > > > > > > +typeattribute test_perm_read_watch_t test_notify_domain; > > > > > > > > > > > > +typeattribute test_perm_read_watch_t testdomain; > > > > > > > > > > > > + > > > > > > > > > > > > +allow test_perm_read_watch_t > > > > > > > > > > > > test_notify_file_t:file { read write open watch > > > > > > > > > > > > watch_with_perm watch_reads }; > > > > > > > > > > > > + > > > > > > > > > > > > +# Domain which CANNOT set any watches > > > > > > > > > > > > +type test_no_watch_t; > > > > > > > > > > > > +domain_type(test_no_watch_t); > > > > > > > > > > > > +unconfined_runs_test(test_no_watch_t); > > > > > > > > > > > > + > > > > > > > > > > > > +typeattribute test_no_watch_t test_notify_domain; > > > > > > > > > > > > +typeattribute test_no_watch_t testdomain; > > > > > > > > > > > > + > > > > > > > > > > > > +allow test_no_watch_t test_notify_file_t:file { read write open }; > > > > > > > > > > > > + > > > > > > > > > > > > +# Domain which has no write access but can watch > > > > > > > > > > > > +type test_rdonly_t; > > > > > > > > > > > > +domain_type(test_rdonly_t); > > > > > > > > > > > > +unconfined_runs_test(test_rdonly_t); > > > > > > > > > > > > + > > > > > > > > > > > > +typeattribute test_rdonly_t test_notify_domain; > > > > > > > > > > > > +typeattribute test_rdonly_t testdomain; > > > > > > > > > > > > + > > > > > > > > > > > > +allow test_rdonly_t test_notify_file_t:file { read open watch }; > > > > > > > > > > > > + > > > > > > > > > > > > +miscfiles_domain_entry_test_files(test_notify_domain); > > > > > > > > > > > > +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); > > > > > > > > > > > > diff --git a/tests/Makefile b/tests/Makefile > > > > > > > > > > > > index 63aa325..b99c96e 100644 > > > > > > > > > > > > --- a/tests/Makefile > > > > > > > > > > > > +++ b/tests/Makefile > > > > > > > > > > > > @@ -50,6 +50,10 @@ ifeq ($(shell grep > > > > > > > > > > > > "^SELINUX_INFINIBAND_PKEY_TEST=" > > > > > > > > > > > > infiniband_pkey/ibpkey_test. > > > > > > > > > > > > SUBDIRS += infiniband_pkey > > > > > > > > > > > > endif > > > > > > > > > > > > +ifeq ($(shell grep -q all_file_perms.*watch > > > > > > > > > > > > $(POLDEV)/include/support/all_perms.spt && echo > > > > > > > > > > > > true),true) > > > > > > > > > > > > +SUBDIRS+=notify > > > > > > > > > > > > +endif > > > > > > > > > > > > + > > > > > > > > > > > > ifeq ($(DISTRO),RHEL4) > > > > > > > > > > > > SUBDIRS:=$(filter-out bounds dyntrace > > > > > > > > > > > > dyntrans inet_socket mmap nnp_nosuid overlay > > > > > > > > > > > > unix_socket, $(SUBDIRS)) > > > > > > > > > > > > endif > > > > > > > > > > > > diff --git a/tests/notify/Makefile b/tests/notify/Makefile > > > > > > > > > > > > new file mode 100644 > > > > > > > > > > > > index 0000000..78c4b3b > > > > > > > > > > > > --- /dev/null > > > > > > > > > > > > +++ b/tests/notify/Makefile > > > > > > > > > > > > @@ -0,0 +1,5 @@ > > > > > > > > > > > > +TARGETS=test_inotify test_fanotify > > > > > > > > > > > > + > > > > > > > > > > > > +all: $(TARGETS) > > > > > > > > > > > > +clean: > > > > > > > > > > > > + rm -f $(TARGETS) > > > > > > > > > > > > diff --git a/tests/notify/test b/tests/notify/test > > > > > > > > > > > > new file mode 100755 > > > > > > > > > > > > index 0000000..21f03de > > > > > > > > > > > > --- /dev/null > > > > > > > > > > > > +++ b/tests/notify/test > > > > > > > > > > > > @@ -0,0 +1,101 @@ > > > > > > > > > > > > +#!/usr/bin/perl > > > > > > > > > > > > + > > > > > > > > > > > > +use Test; > > > > > > > > > > > > +BEGIN { plan tests => 14 } # number of tests to run > > > > > > > > > > > > + > > > > > > > > > > > > +# help the test script locate itself > > > > > > > > > > > > +$basedir = $0; > > > > > > > > > > > > +$basedir =~ s|(.*)/[^/]*|$1|; > > > > > > > > > > > > + > > > > > > > > > > > > +# Get rid of a testfile from last run if it's there (just in case) > > > > > > > > > > > > +system("rm -f $basedir/watch_me"); > > > > > > > > > > > > + > > > > > > > > > > > > +# Create a new test file > > > > > > > > > > > > +system("touch $basedir/watch_me"); > > > > > > > > > > > > +system("chcon -t test_notify_file_t $basedir/watch_me"); > > > > > > > > > > > > + > > > > > > > > > > > > +## TESTS > > > > > > > > > > > > + > > > > > > > > > > > > +## TEST BASIC WATCH PERMISSION > > > > > > > > > > > > +# Should be able to set inotify watch > > > > > > > > > > > > +$exit_val = > > > > > > > > > > > > + system("runcon -t test_watch_t > > > > > > > > > > > > $basedir/test_inotify $basedir/watch_me 2>&1"); > > > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > > > + > > > > > > > > > > > > +# Should be able to set non-permissions based fanotify watch > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > > > $basedir/test_fanotify $basedir/watch_me 2>&1"); > > > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > > > + > > > > > > > > > > > > +# Should NOT be able to set permission based fanotify watch > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > > > $basedir/test_fanotify -p $basedir/watch_me > > > > > > > > > > > > 2>&1"); > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > + > > > > > > > > > > > > +# Should NOT be able to set read based fanotify watch > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > > > $basedir/test_fanotify -r $basedir/watch_me > > > > > > > > > > > > 2>&1"); > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > + > > > > > > > > > > > > +# Should NOT be able to set read based inotify watch > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > > > $basedir/test_inotify -r $basedir/watch_me > > > > > > > > > > > > 2>&1"); > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > + > > > > > > > > > > > > +## TEST PERM WATCH > > > > > > > > > > > > +# Should be able to set permission based fanotify watch > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > +"runcon -t test_perm_watch_t > > > > > > > > > > > > $basedir/test_fanotify -p $basedir/watch_me > > > > > > > > > > > > 2>&1" > > > > > > > > > > > > +); > > > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > > > + > > > > > > > > > > > > +# Should NOT be able to set watch of accesses > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > +"runcon -t test_perm_watch_t > > > > > > > > > > > > $basedir/test_fanotify -r $basedir/watch_me > > > > > > > > > > > > 2>&1" > > > > > > > > > > > > +); > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > + > > > > > > > > > > > > +## TEST READ NO PERM WATCH PERMSISSIONS > > > > > > > > > > > > +# Should NOT be able to set read and perm watch > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > +"runcon -t test_read_watch_t > > > > > > > > > > > > $basedir/test_fanotify -p -r $basedir/watch_me > > > > > > > > > > > > 2>&1" > > > > > > > > > > > > +); > > > > > > > > > > > > +ok($exit_val); # should fail > > > > > > > > > > > > + > > > > > > > > > > > > +# Should be able to set read inotify watch > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > +"runcon -t test_read_watch_t > > > > > > > > > > > > $basedir/test_inotify -r $basedir/watch_me 2>&1" > > > > > > > > > > > > +); > > > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > > > + > > > > > > > > > > > > +## TEST READ WITH PERM WATCH PERMSISSIONS > > > > > > > > > > > > +# Should be able to set read and perm watch > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > +"runcon -t test_perm_read_watch_t > > > > > > > > > > > > $basedir/test_fanotify -p -r $basedir/watch_me > > > > > > > > > > > > 2>&1" > > > > > > > > > > > > +); > > > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > > > + > > > > > > > > > > > > +## TEST NO WATCH PERMSISSIONS > > > > > > > > > > > > +# Should NOT be able to set inotify watch > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > + "runcon -t test_no_watch_t > > > > > > > > > > > > $basedir/test_inotify $basedir/watch_me 2>&1"); > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > + > > > > > > > > > > > > +# Should NOT be able to set any fanotify watch > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > + "runcon -t test_no_watch_t > > > > > > > > > > > > $basedir/test_fanotify $basedir/watch_me 2>&1"); > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > + > > > > > > > > > > > > +## TEST READ ONLY > > > > > > > > > > > > +# Should NOT be able to get read-write descriptor > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > + "runcon -t test_rdonly_t > > > > > > > > > > > > $basedir/test_fanotify -l $basedir/watch_me > > > > > > > > > > > > 2>&1"); > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > + > > > > > > > > > > > > +# Should be able to get read-write descriptor > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > > > $basedir/test_fanotify -l $basedir/watch_me > > > > > > > > > > > > 2>&1"); > > > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > > > + > > > > > > > > > > > > +# Clean up test file > > > > > > > > > > > > +system("rm -f $basedir/watch_me"); > > > > > > > > > > > > diff --git a/tests/notify/test_fanotify.c > > > > > > > > > > > > b/tests/notify/test_fanotify.c > > > > > > > > > > > > new file mode 100644 > > > > > > > > > > > > index 0000000..fff773f > > > > > > > > > > > > --- /dev/null > > > > > > > > > > > > +++ b/tests/notify/test_fanotify.c > > > > > > > > > > > > @@ -0,0 +1,105 @@ > > > > > > > > > > > > +#define _GNU_SOURCE 1 > > > > > > > > > > > > + > > > > > > > > > > > > +#include <stdio.h> > > > > > > > > > > > > +#include <stdlib.h> > > > > > > > > > > > > + > > > > > > > > > > > > +#include <getopt.h> > > > > > > > > > > > > + > > > > > > > > > > > > +#include <fcntl.h> > > > > > > > > > > > > +#include <poll.h> > > > > > > > > > > > > +#include <sys/fanotify.h> > > > > > > > > > > > > +#include <unistd.h> > > > > > > > > > > > > + > > > > > > > > > > > > +void printUsage() > > > > > > > > > > > > +{ > > > > > > > > > > > > + fprintf(stderr, "Usage: test_fanotify [-p] > > > > > > > > > > > > [-r] [-l] file_name\n"); > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > +} > > > > > > > > > > > > + > > > > > > > > > > > > +int main(int argc, char *argv[]) > > > > > > > > > > > > +{ > > > > > > > > > > > > + if (argc < 2) { > > > > > > > > > > > > + printUsage(); > > > > > > > > > > > > + } > > > > > > > > > > > > + > > > > > > > > > > > > + int fd, ret, arg; > > > > > > > > > > > > + int mask = FAN_OPEN; // default mask > > > > > > > > > > > > + int listening = 0; > > > > > > > > > > > > + > > > > > > > > > > > > + // the -p flag will test for watch_with_perm > > > > > > > > > > > > + // the mask used at mark will contain FAN_OPEN_PERM > > > > > > > > > > > > + // > > > > > > > > > > > > + // the -r flag will test for watching > > > > > > > > > > > > accesses to files for reads > > > > > > > > > > > > + // the mask will contain FAN_ACCESS > > > > > > > > > > > > + while ((arg = getopt(argc, argv, "prl")) != -1) { > > > > > > > > > > > > + switch (arg) { > > > > > > > > > > > > + case 'p': > > > > > > > > > > > > + mask |= FAN_OPEN_PERM; > > > > > > > > > > > > + break; > > > > > > > > > > > > + case 'r': > > > > > > > > > > > > + mask |= FAN_ACCESS; > > > > > > > > > > > > + break; > > > > > > > > > > > > + case 'l': > > > > > > > > > > > > + listening = 1; > > > > > > > > > > > > + break; > > > > > > > > > > > > + default: > > > > > > > > > > > > + printUsage(); > > > > > > > > > > > > + } > > > > > > > > > > > > + } > > > > > > > > > > > > + > > > > > > > > > > > > + // get file descriptor for new fanotify event queue > > > > > > > > > > > > + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); > > > > > > > > > > > > + if (fd < 0) { > > > > > > > > > > > > + perror("fanotify_init:bad file descriptor"); > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > + } > > > > > > > > > > > > + > > > > > > > > > > > > + // mark a filesystem object and add mark to event queue > > > > > > > > > > > > + // get notifications on file opens, accesses, and closes > > > > > > > > > > > > + // use current working directory as base dir > > > > > > > > > > > > + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, > > > > > > > > > > > > AT_FDCWD, argv[optind]); > > > > > > > > > > > > + > > > > > > > > > > > > + if (ret < 0) { > > > > > > > > > > > > + perror("test_fanotify:watch denied"); > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > + } > > > > > > > > > > > > + > > > > > > > > > > > > + // logic to actually listen for an event if > > > > > > > > > > > > the -l flag is passed > > > > > > > > > > > > + // this is used to test if an app with > > > > > > > > > > > > read-only access can get a read/write > > > > > > > > > > > > + // handle to the watched file > > > > > > > > > > > > + if (listening) { > > > > > > > > > > > > + if (fork() == 0) { // fork a child > > > > > > > > > > > > process to cause an event on the file > > > > > > > > > > > > + FILE *f; > > > > > > > > > > > > + > > > > > > > > > > > > + f = fopen(argv[optind], "r"); // open file for reading > > > > > > > > > > > > + fgetc(f); // read char from file > > > > > > > > > > > > + > > > > > > > > > > > > + fclose(f); > > > > > > > > > > > > + } else { // logic to watch for events > > > > > > > > > > > > and try to access file read/write > > > > > > > > > > > > + struct pollfd fds; > > > > > > > > > > > > + fds.fd = fd; > > > > > > > > > > > > + fds.events = POLLIN; > > > > > > > > > > > > + > > > > > > > > > > > > + while (listening) { > > > > > > > > > > > > + int polled = poll(&fds, 1, 1); > > > > > > > > > > > > + if (polled > 0) { > > > > > > > > > > > > + if (fds.revents & POLLIN) { > > > > > > > > > > > > + struct fanotify_event_metadata buff[200]; > > > > > > > > > > > > + > > > > > > > > > > > > + size_t len = read(fd, > > > > > > > > > > > > (void *)&buff, sizeof(buff)); > > > > > > > > > > > > + if (len == -1) { > > > > > > > > > > > > + > > > > > > > > > > > > perror("test_fanotify:can't open file"); > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > + } else { > > > > > > > > > > > > + listening = 0; > > > > > > > > > > > > + break; > > > > > > > > > > > > + } > > > > > > > > > > > > + } > > > > > > > > > > > > + } else if (polled == -1) { > > > > > > > > > > > > + listening = 0; > > > > > > > > > > > > + } > > > > > > > > > > > > + } > > > > > > > > > > > > + } > > > > > > > > > > > > + } > > > > > > > > > > > > + exit(0); > > > > > > > > > > > > +} > > > > > > > > > > > > diff --git a/tests/notify/test_inotify.c > > > > > > > > > > > > b/tests/notify/test_inotify.c > > > > > > > > > > > > new file mode 100644 > > > > > > > > > > > > index 0000000..17c3565 > > > > > > > > > > > > --- /dev/null > > > > > > > > > > > > +++ b/tests/notify/test_inotify.c > > > > > > > > > > > > @@ -0,0 +1,43 @@ > > > > > > > > > > > > +#include <stdio.h> > > > > > > > > > > > > +#include <stdlib.h> > > > > > > > > > > > > +#include <sys/inotify.h> > > > > > > > > > > > > +#include <getopt.h> > > > > > > > > > > > > + > > > > > > > > > > > > +int main(int argc, char *argv[]) > > > > > > > > > > > > +{ > > > > > > > > > > > > + if (argc < 2) { > > > > > > > > > > > > + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > + } > > > > > > > > > > > > + > > > > > > > > > > > > + int fd, wd, arg; > > > > > > > > > > > > + int mask = IN_MODIFY; > > > > > > > > > > > > + > > > > > > > > > > > > + while ((arg = getopt(argc, argv, "pr")) != -1) { > > > > > > > > > > > > + switch (arg) { > > > > > > > > > > > > + case 'r': > > > > > > > > > > > > + mask |= IN_ACCESS; > > > > > > > > > > > > + break; > > > > > > > > > > > > + default: > > > > > > > > > > > > + fprintf(stderr, "Usage: > > > > > > > > > > > > test_inotify [-r] file_name\n"); > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > + } > > > > > > > > > > > > + } > > > > > > > > > > > > + > > > > > > > > > > > > + // get new file descriptor for inotify access > > > > > > > > > > > > + fd = inotify_init(); > > > > > > > > > > > > + if (fd < 0) { > > > > > > > > > > > > + perror("inotify_init:bad file descriptor"); > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > + } > > > > > > > > > > > > + > > > > > > > > > > > > + // set watch on file and get watch > > > > > > > > > > > > descriptor for accessing events on it > > > > > > > > > > > > + wd = inotify_add_watch(fd, argv[optind], mask); > > > > > > > > > > > > + > > > > > > > > > > > > + if (wd < 0) { > > > > > > > > > > > > + perror("test_inotify:watch denied"); > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > + } > > > > > > > > > > > > + > > > > > > > > > > > > + exit(0); > > > > > > > > > > > > +} > > > > > > > > > > > > -- > > > > > > > > > > > > 2.21.0 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
On 9/10/19 2:20 PM, Dominick Grift wrote: > On Tue, Sep 10, 2019 at 02:13:07PM -0400, Stephen Smalley wrote: >> On 9/10/19 12:32 PM, Dominick Grift wrote: >>> On Tue, Sep 10, 2019 at 12:25:44PM -0400, Stephen Smalley wrote: >>>> On 9/10/19 11:22 AM, Dominick Grift wrote: >>>>> On Tue, Sep 10, 2019 at 11:02:16AM -0400, Stephen Smalley wrote: >>>>>> On 9/10/19 10:59 AM, Stephen Smalley wrote: >>>>>>> On 9/10/19 10:54 AM, Stephen Smalley wrote: >>>>>>>> On 9/10/19 10:40 AM, Stephen Smalley wrote: >>>>>>>>> On 9/10/19 10:15 AM, Dominick Grift wrote: >>>>>>>>>> On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: >>>>>>>>>>> On 9/10/19 1:59 AM, Dominick Grift wrote: >>>>>>>>>>>> On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: >>>>>>>>>>>>> Added a suite to test permissions for setting >>>>>>>>>>>>> inotify and fanotify watches >>>>>>>>>>>>> on filesystem objects. Tests watch, >>>>>>>>>>>>> watch_with_perm, and watch_reads permissions. >>>>>>>>>>>> >>>>>>>>>>>> Ive also "tested" the fsnotify patch. And my tests >>>>>>>>>>>> indicate that this might cause issues: >>>>>>>>>>>> >>>>>>>>>>>> I added the access vectors to my policy, but on >>>>>>>>>>>> older systems (debian 10) cron fails to start >>>>>>>>>>>> cron needs the "entrypoint" permission on >>>>>>>>>>>> /etc/crontab but it looks like appending the "watch" >>>>>>>>>>>> access vectors to common-file disrupted the ordering >>>>>>>>>>>> The result is that now i have to allow cron to >>>>>>>>>>>> "watch_read" /etc/crontab even though the neither >>>>>>>>>>>> kernel nor selinux user space are aware of the >>>>>>>>>>>> fsnotify access vectors >>>>>>>>>>>> It seems the cron selinux code got confused and now >>>>>>>>>>>> thinks watch_read is entrypoint (its using selinux >>>>>>>>>>>> code to determine whether it can manually transition >>>>>>>>>>>> to cronjob domains on crontabs) >>>>>>>>>>>> >>>>>>>>>>>> I am hoping this issue with resolve itself on >>>>>>>>>>>> systems with kernels and user spaces that suppose >>>>>>>>>>>> fsnotify. >>>>>>>>>>>> However unless i am overlooking something this is >>>>>>>>>>>> still likely to disrupt compatibility >>>>>>>>>>> >>>>>>>>>>> So, IIUC, the issue is that: >>>>>>>>>>> a) older cron was directly using the fixed >>>>>>>>>>> FILE__ENTRYPOINT definition from >>>>>>>>>>> libselinux in a security_compute_av() call rather than >>>>>>>>>>> dynamically looking >>>>>>>>>>> up entrypoint permission, >>>>>>>>>>> b) the value of the file entrypoint permission in policy >>>>>>>>>>> has changed because >>>>>>>>>>> you updated your policy and chose to place the watch* >>>>>>>>>>> permissions in the >>>>>>>>>>> common file definition to match the kernel. >>>>>>>>>>> >>>>>>>>>>> Note that you could have instead sprinkled copies of the >>>>>>>>>>> watch* permissions >>>>>>>>>>> across all of the individual file/dir/*_file classes and >>>>>>>>>>> placed them at the >>>>>>>>>>> end of the classes if you wanted to avoid this >>>>>>>>>>> compatibility issue. The >>>>>>>>>>> policy and kernel definitions no longer need to be >>>>>>>>>>> identical; the kernel >>>>>>>>>>> will dynamically map between them for its own permission checks. >>>>>>>>>>> >>>>>>>>>>> Also, this should have already been broken for you when >>>>>>>>>>> map permission was >>>>>>>>>>> added, which would have shown up as execute_no_trans >>>>>>>>>>> being checked instead >>>>>>>>>>> of entrypoint. This was already filed as a bug on cron >>>>>>>>>>> in debian here: >>>>>>>>>>> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 >>>>>>>>>>> >>>>>>>>>>> So, wrt compatibility, IIUC: >>>>>>>>>>> - the kernel change does not break compatibility for old policy + old >>>>>>>>>>> userspace, >>>>>>>>>>> - new policy can choose to add the new permissions in a >>>>>>>>>>> backward-compatible >>>>>>>>>>> manner if desired, although refpolicy has already chosen >>>>>>>>>>> not to do this for >>>>>>>>>>> map permission, >>>>>>>>>>> - the offending code in cron produces build warnings >>>>>>>>>>> that were introduced in >>>>>>>>>>> 2014 in libselinux to update their code to use the dynamic class/perm >>>>>>>>>>> mapping support, which would resolve the issue. >>>>>>>>>> >>>>>>>>>> this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x >>>>>>>>>> --common common_file >>>>>>>>>> >>>>>>>>>> Commons: 1 >>>>>>>>>> common common_file >>>>>>>>>> { >>>>>>>>>> append >>>>>>>>>> lock >>>>>>>>>> mounton >>>>>>>>>> unlink >>>>>>>>>> read >>>>>>>>>> create >>>>>>>>>> quotaon >>>>>>>>>> execute >>>>>>>>>> setattr >>>>>>>>>> map >>>>>>>>>> relabelto >>>>>>>>>> rename >>>>>>>>>> link >>>>>>>>>> ioctl >>>>>>>>>> getattr >>>>>>>>>> relabelfrom >>>>>>>>>> } >>>>>>>>>> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile >>>>>>>>>> >>>>>>>>>> Classes: 1 >>>>>>>>>> class file >>>>>>>>>> inherits common_file >>>>>>>>>> { >>>>>>>>>> execmod >>>>>>>>>> watch >>>>>>>>>> write >>>>>>>>>> watch_reads >>>>>>>>>> execute_no_trans >>>>>>>>>> watch_mount >>>>>>>>>> watch_with_perm >>>>>>>>>> open >>>>>>>>>> watch_sb >>>>>>>>>> audit_access >>>>>>>>>> entrypoint >>>>>>>>>> } >>>>>>>>> >>>>>>>>> If you want to preserve compatibility with userspace using fixed >>>>>>>>> definitions of FILE__ENTRYPOINT, then you have to insert any new >>>>>>>>> file permissions after the current entrypoint permission in the >>>>>>>>> class file. So watch and friends have to go after it, not before >>>>>>>>> it. >>>>>>>>> >>>>>>>>> Also, since the kernel always uses FILE__WATCH* in the check >>>>>>>>> code rather than distinguishing by class, the watch* permissions >>>>>>>>> need to be at the same offset in all of the file classes. The >>>>>>>>> same is true of the other file permissions. It looks like you >>>>>>>>> may have other permissions out of sync across the file classes >>>>>>>>> e.g. execmod, open, audit_access, that need to be aligned or the >>>>>>>>> kernel could check the wrong permission. >>>>>>>> >>>>>>>> Sorry, the last para isn't correct - it should get mapped correctly >>>>>>>> per class. But you do need to add the permissions after entrypoint >>>>>>>> in the file class to avoid displacing its value. >>>>>>> >>>>>>> Also, it looks like your file class permission order differs in other >>>>>>> incompatible ways. If you want it to be compatible with the deprecated >>>>>>> libselinux headers, the requisite order would be: >>>>>>> class file >>>>>>> inherits common_file >>>>>>> { >>>>>>> execute_no_trans >>>>>>> entrypoint >>>>>>> execmod >>>>>>> open >>>>>>> audit_access >>>>>>> map >>>>>> >>>>>> Sorry, insert watch* permissions here. >>>>> >>>>> I applied brute force: >>>>> >>>>> the map permission can be part of common_file just fine. >>>>> the audit_access av (which was clearly introduced after entrypoint can precede entrypoint just fine. >>>>> >>>>> The problem is the prescence of the fsnotify access vector in general. Moving them out of common_file and after entrypoint does not make a difference. >>>>> As soon as I remove the fsnotify av's things start to work. >>>>> >>>>> In other words. besides the precensce of the fsnotify access vectors everything (seemingly) is in order >>>>> Now for me the question remains: will this issue automatically resolve itself as soon as userspace and kernel support the fsnotify av >>>> >>>> That doesn't make any sense to me. Sounds like a bug somewhere. Anything >>>> that changes the permission bit value in the policy for FILE__ENTRYPOINT is >>>> going to break legacy crond that is using the hardcoded value from the >>>> deprecated libselinux headers. So adding permissions at the end of the file >>>> class should be fine. Adding or removing to/from common file should break. >>>> I can't explain the behavior you are seeing. >>> >>> It does not make sense to me either, but i believe it when i see it. >>> Ive tried several times and just removing the fsnotify access vectors make it work. Whether i append them to common_file or whether i append them to the individual classes does not make a difference. >>> >>> BTW: this fixes it for me: https://lore.kernel.org/selinux/d706a78c-d6d0-13bb-c9af-7ec4365b9b44@debian.org/T/#u >> >> I don't suppose you could make the broken policy available somewhere? Source >> and a binary. > > huh? git clone git://defensec.nl/dssp2.git && cd dssp2 && make all If I build that policy, then the resulting policy yields the following values for the watch* and subsequent permissions: 0x00010000 watch 0x00020000 watch_mount 0x00040000 watch_reads 0x00080000 watch_sb 0x00100000 watch_with_perm 0x00200000 write 0x00400000 audit_access 0x00800000 entrypoint 0x01000000 execmod 0x02000000 execute_no_trans 0x04000000 open You can see this yourself with the attached program. Contrast that with the deprecated definitions in /usr/include/selinux/av_permissions.h that were generated from the old refpolicy access_vectors file long ago: #define FILE__MOUNTON 0x00010000UL #define FILE__EXECUTE_NO_TRANS 0x00020000UL #define FILE__ENTRYPOINT 0x00040000UL #define FILE__EXECMOD 0x00080000UL #define FILE__OPEN 0x00100000UL So when cron tries to check FILE__ENTRYPOINT, it ends up checking the bit for watch_reads instead. In order to avoid this, you would need to synchronize your common_file and file definitions to ensure that your policy still defines entrypoint with the same value. This is what I was trying to achieve by recommending moving the watch* permissions and map permission to the end of the classes. However, what I didn't realize was that you have made multiple other changes to your common_file and file definitions that have perturbed the values in other ways, e.g. you removed swapon (thereby shifting back the values, effectively canceling out the addition of map, such that moving map now actually yields an incorrect entrypoint value). And while you did move audit_access in front of entrypoint in the class file definition, it was already the case that entrypoint was second in the list originally (the first used to be execute_no_trans until you sorted them). If I apply the attached change to merely move the watch permissions, then the correct value is assigned to entrypoint and everything should work even without the cron patch. All that said, I think the cron patch is the right fix - I just wanted to understand what was happening here, which I think I now do. > >> >>> >>>> >>>>>> >>>>>>> } >>>>>>> >>>>>>>> >>>>>>>>> >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> >>>>>>>>>>>>> --- >>>>>>>>>>>>> policy/Makefile | 4 ++ >>>>>>>>>>>>> policy/test_notify.te | 74 ++++++++++++++++++++++++ >>>>>>>>>>>>> tests/Makefile | 4 ++ >>>>>>>>>>>>> tests/notify/Makefile | 5 ++ >>>>>>>>>>>>> tests/notify/test | 101 >>>>>>>>>>>>> +++++++++++++++++++++++++++++++++ >>>>>>>>>>>>> tests/notify/test_fanotify.c | 105 >>>>>>>>>>>>> +++++++++++++++++++++++++++++++++++ >>>>>>>>>>>>> tests/notify/test_inotify.c | 43 ++++++++++++++ >>>>>>>>>>>>> 7 files changed, 336 insertions(+) >>>>>>>>>>>>> create mode 100644 policy/test_notify.te >>>>>>>>>>>>> create mode 100644 tests/notify/Makefile >>>>>>>>>>>>> create mode 100755 tests/notify/test >>>>>>>>>>>>> create mode 100644 tests/notify/test_fanotify.c >>>>>>>>>>>>> create mode 100644 tests/notify/test_inotify.c >>>>>>>>>>>>> >>>>>>>>>>>>> diff --git a/policy/Makefile b/policy/Makefile >>>>>>>>>>>>> index 305b572..65f88c5 100644 >>>>>>>>>>>>> --- a/policy/Makefile >>>>>>>>>>>>> +++ b/policy/Makefile >>>>>>>>>>>>> @@ -71,6 +71,10 @@ ifeq ($(shell grep -q >>>>>>>>>>>>> corenet_sctp_bind_all_nodes >>>>>>>>>>>>> $(POLDEV)/include/kernel/coren >>>>>>>>>>>>> TARGETS += test_sctp.te >>>>>>>>>>>>> endif >>>>>>>>>>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>>>>>>>>>> $(POLDEV)/include/support/all_perms.spt && echo >>>>>>>>>>>>> true),true) >>>>>>>>>>>>> +TARGETS+=test_notify.te >>>>>>>>>>>>> +endif >>>>>>>>>>>>> + >>>>>>>>>>>>> ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) >>>>>>>>>>>>> TARGETS:=$(filter-out test_overlayfs.te >>>>>>>>>>>>> test_mqueue.te, $(TARGETS)) >>>>>>>>>>>>> endif >>>>>>>>>>>>> diff --git a/policy/test_notify.te b/policy/test_notify.te >>>>>>>>>>>>> new file mode 100644 >>>>>>>>>>>>> index 0000000..8ba6f1a >>>>>>>>>>>>> --- /dev/null >>>>>>>>>>>>> +++ b/policy/test_notify.te >>>>>>>>>>>>> @@ -0,0 +1,74 @@ >>>>>>>>>>>>> +#################################################### >>>>>>>>>>>>> +# Policy for testing inoftify and fanotify watches # >>>>>>>>>>>>> +#################################################### >>>>>>>>>>>>> + >>>>>>>>>>>>> +attribute test_notify_domain; >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Type for the file on which we want to set a watch >>>>>>>>>>>>> +type test_notify_file_t; >>>>>>>>>>>>> +files_type(test_notify_file_t); >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Domain for the process which CAN set a non-permission watch >>>>>>>>>>>>> +type test_watch_t; >>>>>>>>>>>>> +domain_type(test_watch_t); >>>>>>>>>>>>> +unconfined_runs_test(test_watch_t); >>>>>>>>>>>>> + >>>>>>>>>>>>> +typeattribute test_watch_t test_notify_domain; >>>>>>>>>>>>> +typeattribute test_watch_t testdomain; >>>>>>>>>>>>> + >>>>>>>>>>>>> +allow test_notify_domain self:capability sys_admin; >>>>>>>>>>>>> + >>>>>>>>>>>>> +allow test_watch_t test_notify_file_t:file { >>>>>>>>>>>>> read write open watch }; >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Domain for the process which CAN set a NON-access watch on a file >>>>>>>>>>>>> +type test_perm_watch_t; >>>>>>>>>>>>> +domain_type(test_perm_watch_t); >>>>>>>>>>>>> +unconfined_runs_test(test_perm_watch_t); >>>>>>>>>>>>> + >>>>>>>>>>>>> +typeattribute test_perm_watch_t test_notify_domain; >>>>>>>>>>>>> +typeattribute test_perm_watch_t testdomain; >>>>>>>>>>>>> + >>>>>>>>>>>>> +allow test_perm_watch_t test_notify_file_t:file >>>>>>>>>>>>> { read write open watch watch_with_perm }; >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Domain which CAN set a NON-perm watch which MAY read accesses >>>>>>>>>>>>> +type test_read_watch_t; >>>>>>>>>>>>> +domain_type(test_read_watch_t); >>>>>>>>>>>>> +unconfined_runs_test(test_read_watch_t); >>>>>>>>>>>>> + >>>>>>>>>>>>> +typeattribute test_read_watch_t test_notify_domain; >>>>>>>>>>>>> +typeattribute test_read_watch_t testdomain; >>>>>>>>>>>>> + >>>>>>>>>>>>> +allow test_read_watch_t test_notify_file_t:file >>>>>>>>>>>>> { read write open watch watch_reads }; >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Domain which CAN set any watch which CAN read accesses >>>>>>>>>>>>> +type test_perm_read_watch_t; >>>>>>>>>>>>> +domain_type(test_perm_read_watch_t); >>>>>>>>>>>>> +unconfined_runs_test(test_perm_read_watch_t); >>>>>>>>>>>>> + >>>>>>>>>>>>> +typeattribute test_perm_read_watch_t test_notify_domain; >>>>>>>>>>>>> +typeattribute test_perm_read_watch_t testdomain; >>>>>>>>>>>>> + >>>>>>>>>>>>> +allow test_perm_read_watch_t >>>>>>>>>>>>> test_notify_file_t:file { read write open watch >>>>>>>>>>>>> watch_with_perm watch_reads }; >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Domain which CANNOT set any watches >>>>>>>>>>>>> +type test_no_watch_t; >>>>>>>>>>>>> +domain_type(test_no_watch_t); >>>>>>>>>>>>> +unconfined_runs_test(test_no_watch_t); >>>>>>>>>>>>> + >>>>>>>>>>>>> +typeattribute test_no_watch_t test_notify_domain; >>>>>>>>>>>>> +typeattribute test_no_watch_t testdomain; >>>>>>>>>>>>> + >>>>>>>>>>>>> +allow test_no_watch_t test_notify_file_t:file { read write open }; >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Domain which has no write access but can watch >>>>>>>>>>>>> +type test_rdonly_t; >>>>>>>>>>>>> +domain_type(test_rdonly_t); >>>>>>>>>>>>> +unconfined_runs_test(test_rdonly_t); >>>>>>>>>>>>> + >>>>>>>>>>>>> +typeattribute test_rdonly_t test_notify_domain; >>>>>>>>>>>>> +typeattribute test_rdonly_t testdomain; >>>>>>>>>>>>> + >>>>>>>>>>>>> +allow test_rdonly_t test_notify_file_t:file { read open watch }; >>>>>>>>>>>>> + >>>>>>>>>>>>> +miscfiles_domain_entry_test_files(test_notify_domain); >>>>>>>>>>>>> +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); >>>>>>>>>>>>> diff --git a/tests/Makefile b/tests/Makefile >>>>>>>>>>>>> index 63aa325..b99c96e 100644 >>>>>>>>>>>>> --- a/tests/Makefile >>>>>>>>>>>>> +++ b/tests/Makefile >>>>>>>>>>>>> @@ -50,6 +50,10 @@ ifeq ($(shell grep >>>>>>>>>>>>> "^SELINUX_INFINIBAND_PKEY_TEST=" >>>>>>>>>>>>> infiniband_pkey/ibpkey_test. >>>>>>>>>>>>> SUBDIRS += infiniband_pkey >>>>>>>>>>>>> endif >>>>>>>>>>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>>>>>>>>>> $(POLDEV)/include/support/all_perms.spt && echo >>>>>>>>>>>>> true),true) >>>>>>>>>>>>> +SUBDIRS+=notify >>>>>>>>>>>>> +endif >>>>>>>>>>>>> + >>>>>>>>>>>>> ifeq ($(DISTRO),RHEL4) >>>>>>>>>>>>> SUBDIRS:=$(filter-out bounds dyntrace >>>>>>>>>>>>> dyntrans inet_socket mmap nnp_nosuid overlay >>>>>>>>>>>>> unix_socket, $(SUBDIRS)) >>>>>>>>>>>>> endif >>>>>>>>>>>>> diff --git a/tests/notify/Makefile b/tests/notify/Makefile >>>>>>>>>>>>> new file mode 100644 >>>>>>>>>>>>> index 0000000..78c4b3b >>>>>>>>>>>>> --- /dev/null >>>>>>>>>>>>> +++ b/tests/notify/Makefile >>>>>>>>>>>>> @@ -0,0 +1,5 @@ >>>>>>>>>>>>> +TARGETS=test_inotify test_fanotify >>>>>>>>>>>>> + >>>>>>>>>>>>> +all: $(TARGETS) >>>>>>>>>>>>> +clean: >>>>>>>>>>>>> + rm -f $(TARGETS) >>>>>>>>>>>>> diff --git a/tests/notify/test b/tests/notify/test >>>>>>>>>>>>> new file mode 100755 >>>>>>>>>>>>> index 0000000..21f03de >>>>>>>>>>>>> --- /dev/null >>>>>>>>>>>>> +++ b/tests/notify/test >>>>>>>>>>>>> @@ -0,0 +1,101 @@ >>>>>>>>>>>>> +#!/usr/bin/perl >>>>>>>>>>>>> + >>>>>>>>>>>>> +use Test; >>>>>>>>>>>>> +BEGIN { plan tests => 14 } # number of tests to run >>>>>>>>>>>>> + >>>>>>>>>>>>> +# help the test script locate itself >>>>>>>>>>>>> +$basedir = $0; >>>>>>>>>>>>> +$basedir =~ s|(.*)/[^/]*|$1|; >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Get rid of a testfile from last run if it's there (just in case) >>>>>>>>>>>>> +system("rm -f $basedir/watch_me"); >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Create a new test file >>>>>>>>>>>>> +system("touch $basedir/watch_me"); >>>>>>>>>>>>> +system("chcon -t test_notify_file_t $basedir/watch_me"); >>>>>>>>>>>>> + >>>>>>>>>>>>> +## TESTS >>>>>>>>>>>>> + >>>>>>>>>>>>> +## TEST BASIC WATCH PERMISSION >>>>>>>>>>>>> +# Should be able to set inotify watch >>>>>>>>>>>>> +$exit_val = >>>>>>>>>>>>> + system("runcon -t test_watch_t >>>>>>>>>>>>> $basedir/test_inotify $basedir/watch_me 2>&1"); >>>>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Should be able to set non-permissions based fanotify watch >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>>>> $basedir/test_fanotify $basedir/watch_me 2>&1"); >>>>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Should NOT be able to set permission based fanotify watch >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>>>> $basedir/test_fanotify -p $basedir/watch_me >>>>>>>>>>>>> 2>&1"); >>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Should NOT be able to set read based fanotify watch >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>>>> $basedir/test_fanotify -r $basedir/watch_me >>>>>>>>>>>>> 2>&1"); >>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Should NOT be able to set read based inotify watch >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>>>> $basedir/test_inotify -r $basedir/watch_me >>>>>>>>>>>>> 2>&1"); >>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>> + >>>>>>>>>>>>> +## TEST PERM WATCH >>>>>>>>>>>>> +# Should be able to set permission based fanotify watch >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> +"runcon -t test_perm_watch_t >>>>>>>>>>>>> $basedir/test_fanotify -p $basedir/watch_me >>>>>>>>>>>>> 2>&1" >>>>>>>>>>>>> +); >>>>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Should NOT be able to set watch of accesses >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> +"runcon -t test_perm_watch_t >>>>>>>>>>>>> $basedir/test_fanotify -r $basedir/watch_me >>>>>>>>>>>>> 2>&1" >>>>>>>>>>>>> +); >>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>> + >>>>>>>>>>>>> +## TEST READ NO PERM WATCH PERMSISSIONS >>>>>>>>>>>>> +# Should NOT be able to set read and perm watch >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> +"runcon -t test_read_watch_t >>>>>>>>>>>>> $basedir/test_fanotify -p -r $basedir/watch_me >>>>>>>>>>>>> 2>&1" >>>>>>>>>>>>> +); >>>>>>>>>>>>> +ok($exit_val); # should fail >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Should be able to set read inotify watch >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> +"runcon -t test_read_watch_t >>>>>>>>>>>>> $basedir/test_inotify -r $basedir/watch_me 2>&1" >>>>>>>>>>>>> +); >>>>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>>>> + >>>>>>>>>>>>> +## TEST READ WITH PERM WATCH PERMSISSIONS >>>>>>>>>>>>> +# Should be able to set read and perm watch >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> +"runcon -t test_perm_read_watch_t >>>>>>>>>>>>> $basedir/test_fanotify -p -r $basedir/watch_me >>>>>>>>>>>>> 2>&1" >>>>>>>>>>>>> +); >>>>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>>>> + >>>>>>>>>>>>> +## TEST NO WATCH PERMSISSIONS >>>>>>>>>>>>> +# Should NOT be able to set inotify watch >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> + "runcon -t test_no_watch_t >>>>>>>>>>>>> $basedir/test_inotify $basedir/watch_me 2>&1"); >>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Should NOT be able to set any fanotify watch >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> + "runcon -t test_no_watch_t >>>>>>>>>>>>> $basedir/test_fanotify $basedir/watch_me 2>&1"); >>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>> + >>>>>>>>>>>>> +## TEST READ ONLY >>>>>>>>>>>>> +# Should NOT be able to get read-write descriptor >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> + "runcon -t test_rdonly_t >>>>>>>>>>>>> $basedir/test_fanotify -l $basedir/watch_me >>>>>>>>>>>>> 2>&1"); >>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Should be able to get read-write descriptor >>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>>>> $basedir/test_fanotify -l $basedir/watch_me >>>>>>>>>>>>> 2>&1"); >>>>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>>>> + >>>>>>>>>>>>> +# Clean up test file >>>>>>>>>>>>> +system("rm -f $basedir/watch_me"); >>>>>>>>>>>>> diff --git a/tests/notify/test_fanotify.c >>>>>>>>>>>>> b/tests/notify/test_fanotify.c >>>>>>>>>>>>> new file mode 100644 >>>>>>>>>>>>> index 0000000..fff773f >>>>>>>>>>>>> --- /dev/null >>>>>>>>>>>>> +++ b/tests/notify/test_fanotify.c >>>>>>>>>>>>> @@ -0,0 +1,105 @@ >>>>>>>>>>>>> +#define _GNU_SOURCE 1 >>>>>>>>>>>>> + >>>>>>>>>>>>> +#include <stdio.h> >>>>>>>>>>>>> +#include <stdlib.h> >>>>>>>>>>>>> + >>>>>>>>>>>>> +#include <getopt.h> >>>>>>>>>>>>> + >>>>>>>>>>>>> +#include <fcntl.h> >>>>>>>>>>>>> +#include <poll.h> >>>>>>>>>>>>> +#include <sys/fanotify.h> >>>>>>>>>>>>> +#include <unistd.h> >>>>>>>>>>>>> + >>>>>>>>>>>>> +void printUsage() >>>>>>>>>>>>> +{ >>>>>>>>>>>>> + fprintf(stderr, "Usage: test_fanotify [-p] >>>>>>>>>>>>> [-r] [-l] file_name\n"); >>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>> +} >>>>>>>>>>>>> + >>>>>>>>>>>>> +int main(int argc, char *argv[]) >>>>>>>>>>>>> +{ >>>>>>>>>>>>> + if (argc < 2) { >>>>>>>>>>>>> + printUsage(); >>>>>>>>>>>>> + } >>>>>>>>>>>>> + >>>>>>>>>>>>> + int fd, ret, arg; >>>>>>>>>>>>> + int mask = FAN_OPEN; // default mask >>>>>>>>>>>>> + int listening = 0; >>>>>>>>>>>>> + >>>>>>>>>>>>> + // the -p flag will test for watch_with_perm >>>>>>>>>>>>> + // the mask used at mark will contain FAN_OPEN_PERM >>>>>>>>>>>>> + // >>>>>>>>>>>>> + // the -r flag will test for watching >>>>>>>>>>>>> accesses to files for reads >>>>>>>>>>>>> + // the mask will contain FAN_ACCESS >>>>>>>>>>>>> + while ((arg = getopt(argc, argv, "prl")) != -1) { >>>>>>>>>>>>> + switch (arg) { >>>>>>>>>>>>> + case 'p': >>>>>>>>>>>>> + mask |= FAN_OPEN_PERM; >>>>>>>>>>>>> + break; >>>>>>>>>>>>> + case 'r': >>>>>>>>>>>>> + mask |= FAN_ACCESS; >>>>>>>>>>>>> + break; >>>>>>>>>>>>> + case 'l': >>>>>>>>>>>>> + listening = 1; >>>>>>>>>>>>> + break; >>>>>>>>>>>>> + default: >>>>>>>>>>>>> + printUsage(); >>>>>>>>>>>>> + } >>>>>>>>>>>>> + } >>>>>>>>>>>>> + >>>>>>>>>>>>> + // get file descriptor for new fanotify event queue >>>>>>>>>>>>> + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); >>>>>>>>>>>>> + if (fd < 0) { >>>>>>>>>>>>> + perror("fanotify_init:bad file descriptor"); >>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>> + } >>>>>>>>>>>>> + >>>>>>>>>>>>> + // mark a filesystem object and add mark to event queue >>>>>>>>>>>>> + // get notifications on file opens, accesses, and closes >>>>>>>>>>>>> + // use current working directory as base dir >>>>>>>>>>>>> + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, >>>>>>>>>>>>> AT_FDCWD, argv[optind]); >>>>>>>>>>>>> + >>>>>>>>>>>>> + if (ret < 0) { >>>>>>>>>>>>> + perror("test_fanotify:watch denied"); >>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>> + } >>>>>>>>>>>>> + >>>>>>>>>>>>> + // logic to actually listen for an event if >>>>>>>>>>>>> the -l flag is passed >>>>>>>>>>>>> + // this is used to test if an app with >>>>>>>>>>>>> read-only access can get a read/write >>>>>>>>>>>>> + // handle to the watched file >>>>>>>>>>>>> + if (listening) { >>>>>>>>>>>>> + if (fork() == 0) { // fork a child >>>>>>>>>>>>> process to cause an event on the file >>>>>>>>>>>>> + FILE *f; >>>>>>>>>>>>> + >>>>>>>>>>>>> + f = fopen(argv[optind], "r"); // open file for reading >>>>>>>>>>>>> + fgetc(f); // read char from file >>>>>>>>>>>>> + >>>>>>>>>>>>> + fclose(f); >>>>>>>>>>>>> + } else { // logic to watch for events >>>>>>>>>>>>> and try to access file read/write >>>>>>>>>>>>> + struct pollfd fds; >>>>>>>>>>>>> + fds.fd = fd; >>>>>>>>>>>>> + fds.events = POLLIN; >>>>>>>>>>>>> + >>>>>>>>>>>>> + while (listening) { >>>>>>>>>>>>> + int polled = poll(&fds, 1, 1); >>>>>>>>>>>>> + if (polled > 0) { >>>>>>>>>>>>> + if (fds.revents & POLLIN) { >>>>>>>>>>>>> + struct fanotify_event_metadata buff[200]; >>>>>>>>>>>>> + >>>>>>>>>>>>> + size_t len = read(fd, >>>>>>>>>>>>> (void *)&buff, sizeof(buff)); >>>>>>>>>>>>> + if (len == -1) { >>>>>>>>>>>>> + >>>>>>>>>>>>> perror("test_fanotify:can't open file"); >>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>> + } else { >>>>>>>>>>>>> + listening = 0; >>>>>>>>>>>>> + break; >>>>>>>>>>>>> + } >>>>>>>>>>>>> + } >>>>>>>>>>>>> + } else if (polled == -1) { >>>>>>>>>>>>> + listening = 0; >>>>>>>>>>>>> + } >>>>>>>>>>>>> + } >>>>>>>>>>>>> + } >>>>>>>>>>>>> + } >>>>>>>>>>>>> + exit(0); >>>>>>>>>>>>> +} >>>>>>>>>>>>> diff --git a/tests/notify/test_inotify.c >>>>>>>>>>>>> b/tests/notify/test_inotify.c >>>>>>>>>>>>> new file mode 100644 >>>>>>>>>>>>> index 0000000..17c3565 >>>>>>>>>>>>> --- /dev/null >>>>>>>>>>>>> +++ b/tests/notify/test_inotify.c >>>>>>>>>>>>> @@ -0,0 +1,43 @@ >>>>>>>>>>>>> +#include <stdio.h> >>>>>>>>>>>>> +#include <stdlib.h> >>>>>>>>>>>>> +#include <sys/inotify.h> >>>>>>>>>>>>> +#include <getopt.h> >>>>>>>>>>>>> + >>>>>>>>>>>>> +int main(int argc, char *argv[]) >>>>>>>>>>>>> +{ >>>>>>>>>>>>> + if (argc < 2) { >>>>>>>>>>>>> + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); >>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>> + } >>>>>>>>>>>>> + >>>>>>>>>>>>> + int fd, wd, arg; >>>>>>>>>>>>> + int mask = IN_MODIFY; >>>>>>>>>>>>> + >>>>>>>>>>>>> + while ((arg = getopt(argc, argv, "pr")) != -1) { >>>>>>>>>>>>> + switch (arg) { >>>>>>>>>>>>> + case 'r': >>>>>>>>>>>>> + mask |= IN_ACCESS; >>>>>>>>>>>>> + break; >>>>>>>>>>>>> + default: >>>>>>>>>>>>> + fprintf(stderr, "Usage: >>>>>>>>>>>>> test_inotify [-r] file_name\n"); >>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>> + } >>>>>>>>>>>>> + } >>>>>>>>>>>>> + >>>>>>>>>>>>> + // get new file descriptor for inotify access >>>>>>>>>>>>> + fd = inotify_init(); >>>>>>>>>>>>> + if (fd < 0) { >>>>>>>>>>>>> + perror("inotify_init:bad file descriptor"); >>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>> + } >>>>>>>>>>>>> + >>>>>>>>>>>>> + // set watch on file and get watch >>>>>>>>>>>>> descriptor for accessing events on it >>>>>>>>>>>>> + wd = inotify_add_watch(fd, argv[optind], mask); >>>>>>>>>>>>> + >>>>>>>>>>>>> + if (wd < 0) { >>>>>>>>>>>>> + perror("test_inotify:watch denied"); >>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>> + } >>>>>>>>>>>>> + >>>>>>>>>>>>> + exit(0); >>>>>>>>>>>>> +} >>>>>>>>>>>>> -- >>>>>>>>>>>>> 2.21.0 >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> >
On 9/10/19 3:45 PM, Stephen Smalley wrote: > On 9/10/19 2:20 PM, Dominick Grift wrote: >> On Tue, Sep 10, 2019 at 02:13:07PM -0400, Stephen Smalley wrote: >>> On 9/10/19 12:32 PM, Dominick Grift wrote: >>>> On Tue, Sep 10, 2019 at 12:25:44PM -0400, Stephen Smalley wrote: >>>>> On 9/10/19 11:22 AM, Dominick Grift wrote: >>>>>> On Tue, Sep 10, 2019 at 11:02:16AM -0400, Stephen Smalley wrote: >>>>>>> On 9/10/19 10:59 AM, Stephen Smalley wrote: >>>>>>>> On 9/10/19 10:54 AM, Stephen Smalley wrote: >>>>>>>>> On 9/10/19 10:40 AM, Stephen Smalley wrote: >>>>>>>>>> On 9/10/19 10:15 AM, Dominick Grift wrote: >>>>>>>>>>> On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: >>>>>>>>>>>> On 9/10/19 1:59 AM, Dominick Grift wrote: >>>>>>>>>>>>> On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: >>>>>>>>>>>>>> Added a suite to test permissions for setting >>>>>>>>>>>>>> inotify and fanotify watches >>>>>>>>>>>>>> on filesystem objects. Tests watch, >>>>>>>>>>>>>> watch_with_perm, and watch_reads permissions. >>>>>>>>>>>>> >>>>>>>>>>>>> Ive also "tested" the fsnotify patch. And my tests >>>>>>>>>>>>> indicate that this might cause issues: >>>>>>>>>>>>> >>>>>>>>>>>>> I added the access vectors to my policy, but on >>>>>>>>>>>>> older systems (debian 10) cron fails to start >>>>>>>>>>>>> cron needs the "entrypoint" permission on >>>>>>>>>>>>> /etc/crontab but it looks like appending the "watch" >>>>>>>>>>>>> access vectors to common-file disrupted the ordering >>>>>>>>>>>>> The result is that now i have to allow cron to >>>>>>>>>>>>> "watch_read" /etc/crontab even though the neither >>>>>>>>>>>>> kernel nor selinux user space are aware of the >>>>>>>>>>>>> fsnotify access vectors >>>>>>>>>>>>> It seems the cron selinux code got confused and now >>>>>>>>>>>>> thinks watch_read is entrypoint (its using selinux >>>>>>>>>>>>> code to determine whether it can manually transition >>>>>>>>>>>>> to cronjob domains on crontabs) >>>>>>>>>>>>> >>>>>>>>>>>>> I am hoping this issue with resolve itself on >>>>>>>>>>>>> systems with kernels and user spaces that suppose >>>>>>>>>>>>> fsnotify. >>>>>>>>>>>>> However unless i am overlooking something this is >>>>>>>>>>>>> still likely to disrupt compatibility >>>>>>>>>>>> >>>>>>>>>>>> So, IIUC, the issue is that: >>>>>>>>>>>> a) older cron was directly using the fixed >>>>>>>>>>>> FILE__ENTRYPOINT definition from >>>>>>>>>>>> libselinux in a security_compute_av() call rather than >>>>>>>>>>>> dynamically looking >>>>>>>>>>>> up entrypoint permission, >>>>>>>>>>>> b) the value of the file entrypoint permission in policy >>>>>>>>>>>> has changed because >>>>>>>>>>>> you updated your policy and chose to place the watch* >>>>>>>>>>>> permissions in the >>>>>>>>>>>> common file definition to match the kernel. >>>>>>>>>>>> >>>>>>>>>>>> Note that you could have instead sprinkled copies of the >>>>>>>>>>>> watch* permissions >>>>>>>>>>>> across all of the individual file/dir/*_file classes and >>>>>>>>>>>> placed them at the >>>>>>>>>>>> end of the classes if you wanted to avoid this >>>>>>>>>>>> compatibility issue. The >>>>>>>>>>>> policy and kernel definitions no longer need to be >>>>>>>>>>>> identical; the kernel >>>>>>>>>>>> will dynamically map between them for its own permission >>>>>>>>>>>> checks. >>>>>>>>>>>> >>>>>>>>>>>> Also, this should have already been broken for you when >>>>>>>>>>>> map permission was >>>>>>>>>>>> added, which would have shown up as execute_no_trans >>>>>>>>>>>> being checked instead >>>>>>>>>>>> of entrypoint. This was already filed as a bug on cron >>>>>>>>>>>> in debian here: >>>>>>>>>>>> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 >>>>>>>>>>>> >>>>>>>>>>>> So, wrt compatibility, IIUC: >>>>>>>>>>>> - the kernel change does not break compatibility for old >>>>>>>>>>>> policy + old >>>>>>>>>>>> userspace, >>>>>>>>>>>> - new policy can choose to add the new permissions in a >>>>>>>>>>>> backward-compatible >>>>>>>>>>>> manner if desired, although refpolicy has already chosen >>>>>>>>>>>> not to do this for >>>>>>>>>>>> map permission, >>>>>>>>>>>> - the offending code in cron produces build warnings >>>>>>>>>>>> that were introduced in >>>>>>>>>>>> 2014 in libselinux to update their code to use the dynamic >>>>>>>>>>>> class/perm >>>>>>>>>>>> mapping support, which would resolve the issue. >>>>>>>>>>> >>>>>>>>>>> this does not work (cron[8934]: ((null)) ENTRYPOINT FAILED): >>>>>>>>>>> https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x >>>>>>>>>>> --common common_file >>>>>>>>>>> >>>>>>>>>>> Commons: 1 >>>>>>>>>>> common common_file >>>>>>>>>>> { >>>>>>>>>>> append >>>>>>>>>>> lock >>>>>>>>>>> mounton >>>>>>>>>>> unlink >>>>>>>>>>> read >>>>>>>>>>> create >>>>>>>>>>> quotaon >>>>>>>>>>> execute >>>>>>>>>>> setattr >>>>>>>>>>> map >>>>>>>>>>> relabelto >>>>>>>>>>> rename >>>>>>>>>>> link >>>>>>>>>>> ioctl >>>>>>>>>>> getattr >>>>>>>>>>> relabelfrom >>>>>>>>>>> } >>>>>>>>>>> [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile >>>>>>>>>>> >>>>>>>>>>> Classes: 1 >>>>>>>>>>> class file >>>>>>>>>>> inherits common_file >>>>>>>>>>> { >>>>>>>>>>> execmod >>>>>>>>>>> watch >>>>>>>>>>> write >>>>>>>>>>> watch_reads >>>>>>>>>>> execute_no_trans >>>>>>>>>>> watch_mount >>>>>>>>>>> watch_with_perm >>>>>>>>>>> open >>>>>>>>>>> watch_sb >>>>>>>>>>> audit_access >>>>>>>>>>> entrypoint >>>>>>>>>>> } >>>>>>>>>> >>>>>>>>>> If you want to preserve compatibility with userspace using fixed >>>>>>>>>> definitions of FILE__ENTRYPOINT, then you have to insert any new >>>>>>>>>> file permissions after the current entrypoint permission in the >>>>>>>>>> class file. So watch and friends have to go after it, not before >>>>>>>>>> it. >>>>>>>>>> >>>>>>>>>> Also, since the kernel always uses FILE__WATCH* in the check >>>>>>>>>> code rather than distinguishing by class, the watch* permissions >>>>>>>>>> need to be at the same offset in all of the file classes. The >>>>>>>>>> same is true of the other file permissions. It looks like you >>>>>>>>>> may have other permissions out of sync across the file classes >>>>>>>>>> e.g. execmod, open, audit_access, that need to be aligned or the >>>>>>>>>> kernel could check the wrong permission. >>>>>>>>> >>>>>>>>> Sorry, the last para isn't correct - it should get mapped >>>>>>>>> correctly >>>>>>>>> per class. But you do need to add the permissions after >>>>>>>>> entrypoint >>>>>>>>> in the file class to avoid displacing its value. >>>>>>>> >>>>>>>> Also, it looks like your file class permission order differs in >>>>>>>> other >>>>>>>> incompatible ways. If you want it to be compatible with the >>>>>>>> deprecated >>>>>>>> libselinux headers, the requisite order would be: >>>>>>>> class file >>>>>>>> inherits common_file >>>>>>>> { >>>>>>>> execute_no_trans >>>>>>>> entrypoint >>>>>>>> execmod >>>>>>>> open >>>>>>>> audit_access >>>>>>>> map >>>>>>> >>>>>>> Sorry, insert watch* permissions here. >>>>>> >>>>>> I applied brute force: >>>>>> >>>>>> the map permission can be part of common_file just fine. >>>>>> the audit_access av (which was clearly introduced after entrypoint >>>>>> can precede entrypoint just fine. >>>>>> >>>>>> The problem is the prescence of the fsnotify access vector in >>>>>> general. Moving them out of common_file and after entrypoint does >>>>>> not make a difference. >>>>>> As soon as I remove the fsnotify av's things start to work. >>>>>> >>>>>> In other words. besides the precensce of the fsnotify access >>>>>> vectors everything (seemingly) is in order >>>>>> Now for me the question remains: will this issue automatically >>>>>> resolve itself as soon as userspace and kernel support the >>>>>> fsnotify av >>>>> >>>>> That doesn't make any sense to me. Sounds like a bug somewhere. >>>>> Anything >>>>> that changes the permission bit value in the policy for >>>>> FILE__ENTRYPOINT is >>>>> going to break legacy crond that is using the hardcoded value from the >>>>> deprecated libselinux headers. So adding permissions at the end of >>>>> the file >>>>> class should be fine. Adding or removing to/from common file >>>>> should break. >>>>> I can't explain the behavior you are seeing. >>>> >>>> It does not make sense to me either, but i believe it when i see it. >>>> Ive tried several times and just removing the fsnotify access >>>> vectors make it work. Whether i append them to common_file or >>>> whether i append them to the individual classes does not make a >>>> difference. >>>> >>>> BTW: this fixes it for me: >>>> https://lore.kernel.org/selinux/d706a78c-d6d0-13bb-c9af-7ec4365b9b44@debian.org/T/#u >>>> >>> >>> I don't suppose you could make the broken policy available somewhere? >>> Source >>> and a binary. >> >> huh? git clone git://defensec.nl/dssp2.git && cd dssp2 && make all > > If I build that policy, then the resulting policy yields the following > values for the watch* and subsequent permissions: > 0x00010000 watch > 0x00020000 watch_mount > 0x00040000 watch_reads > 0x00080000 watch_sb > 0x00100000 watch_with_perm > 0x00200000 write > 0x00400000 audit_access > 0x00800000 entrypoint > 0x01000000 execmod > 0x02000000 execute_no_trans > 0x04000000 open > > You can see this yourself with the attached program. > > Contrast that with the deprecated definitions in > /usr/include/selinux/av_permissions.h that were generated from the old > refpolicy access_vectors file long ago: > #define FILE__MOUNTON 0x00010000UL > #define FILE__EXECUTE_NO_TRANS 0x00020000UL > #define FILE__ENTRYPOINT 0x00040000UL > #define FILE__EXECMOD 0x00080000UL > #define FILE__OPEN 0x00100000UL > > So when cron tries to check FILE__ENTRYPOINT, it ends up checking the > bit for watch_reads instead. > > In order to avoid this, you would need to synchronize your common_file > and file definitions to ensure that your policy still defines entrypoint > with the same value. This is what I was trying to achieve by > recommending moving the watch* permissions and map permission to the end > of the classes. However, what I didn't realize was that you have made > multiple other changes to your common_file and file definitions that > have perturbed the values in other ways, e.g. you removed swapon > (thereby shifting back the values, effectively canceling out the > addition of map, such that moving map now actually yields an incorrect > entrypoint value). And while you did move audit_access in front of > entrypoint in the class file definition, it was already the case that > entrypoint was second in the list originally (the first used to be > execute_no_trans until you sorted them). > > If I apply the attached change to merely move the watch permissions, > then the correct value is assigned to entrypoint and everything should > work even without the cron patch. > > All that said, I think the cron patch is the right fix - I just wanted > to understand what was happening here, which I think I now do. Also, looking at your git history, your earlier attempt to move just the watch permissions was broken because it also moved the "write" permission along with it, thereby shifting the class file permission values back one too many. > >> >>> >>>> >>>>> >>>>>>> >>>>>>>> } >>>>>>>> >>>>>>>>> >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>>> Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> >>>>>>>>>>>>>> --- >>>>>>>>>>>>>> policy/Makefile | 4 ++ >>>>>>>>>>>>>> policy/test_notify.te | 74 >>>>>>>>>>>>>> ++++++++++++++++++++++++ >>>>>>>>>>>>>> tests/Makefile | 4 ++ >>>>>>>>>>>>>> tests/notify/Makefile | 5 ++ >>>>>>>>>>>>>> tests/notify/test | 101 >>>>>>>>>>>>>> +++++++++++++++++++++++++++++++++ >>>>>>>>>>>>>> tests/notify/test_fanotify.c | 105 >>>>>>>>>>>>>> +++++++++++++++++++++++++++++++++++ >>>>>>>>>>>>>> tests/notify/test_inotify.c | 43 ++++++++++++++ >>>>>>>>>>>>>> 7 files changed, 336 insertions(+) >>>>>>>>>>>>>> create mode 100644 policy/test_notify.te >>>>>>>>>>>>>> create mode 100644 tests/notify/Makefile >>>>>>>>>>>>>> create mode 100755 tests/notify/test >>>>>>>>>>>>>> create mode 100644 tests/notify/test_fanotify.c >>>>>>>>>>>>>> create mode 100644 tests/notify/test_inotify.c >>>>>>>>>>>>>> >>>>>>>>>>>>>> diff --git a/policy/Makefile b/policy/Makefile >>>>>>>>>>>>>> index 305b572..65f88c5 100644 >>>>>>>>>>>>>> --- a/policy/Makefile >>>>>>>>>>>>>> +++ b/policy/Makefile >>>>>>>>>>>>>> @@ -71,6 +71,10 @@ ifeq ($(shell grep -q >>>>>>>>>>>>>> corenet_sctp_bind_all_nodes >>>>>>>>>>>>>> $(POLDEV)/include/kernel/coren >>>>>>>>>>>>>> TARGETS += test_sctp.te >>>>>>>>>>>>>> endif >>>>>>>>>>>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>>>>>>>>>>> $(POLDEV)/include/support/all_perms.spt && echo >>>>>>>>>>>>>> true),true) >>>>>>>>>>>>>> +TARGETS+=test_notify.te >>>>>>>>>>>>>> +endif >>>>>>>>>>>>>> + >>>>>>>>>>>>>> ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 >>>>>>>>>>>>>> xRHEL6)) >>>>>>>>>>>>>> TARGETS:=$(filter-out test_overlayfs.te >>>>>>>>>>>>>> test_mqueue.te, $(TARGETS)) >>>>>>>>>>>>>> endif >>>>>>>>>>>>>> diff --git a/policy/test_notify.te b/policy/test_notify.te >>>>>>>>>>>>>> new file mode 100644 >>>>>>>>>>>>>> index 0000000..8ba6f1a >>>>>>>>>>>>>> --- /dev/null >>>>>>>>>>>>>> +++ b/policy/test_notify.te >>>>>>>>>>>>>> @@ -0,0 +1,74 @@ >>>>>>>>>>>>>> +#################################################### >>>>>>>>>>>>>> +# Policy for testing inoftify and fanotify watches # >>>>>>>>>>>>>> +#################################################### >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +attribute test_notify_domain; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Type for the file on which we want to set a watch >>>>>>>>>>>>>> +type test_notify_file_t; >>>>>>>>>>>>>> +files_type(test_notify_file_t); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Domain for the process which CAN set a non-permission >>>>>>>>>>>>>> watch >>>>>>>>>>>>>> +type test_watch_t; >>>>>>>>>>>>>> +domain_type(test_watch_t); >>>>>>>>>>>>>> +unconfined_runs_test(test_watch_t); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +typeattribute test_watch_t test_notify_domain; >>>>>>>>>>>>>> +typeattribute test_watch_t testdomain; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +allow test_notify_domain self:capability sys_admin; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +allow test_watch_t test_notify_file_t:file { >>>>>>>>>>>>>> read write open watch }; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Domain for the process which CAN set a NON-access watch >>>>>>>>>>>>>> on a file >>>>>>>>>>>>>> +type test_perm_watch_t; >>>>>>>>>>>>>> +domain_type(test_perm_watch_t); >>>>>>>>>>>>>> +unconfined_runs_test(test_perm_watch_t); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +typeattribute test_perm_watch_t test_notify_domain; >>>>>>>>>>>>>> +typeattribute test_perm_watch_t testdomain; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +allow test_perm_watch_t test_notify_file_t:file >>>>>>>>>>>>>> { read write open watch watch_with_perm }; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Domain which CAN set a NON-perm watch which MAY read >>>>>>>>>>>>>> accesses >>>>>>>>>>>>>> +type test_read_watch_t; >>>>>>>>>>>>>> +domain_type(test_read_watch_t); >>>>>>>>>>>>>> +unconfined_runs_test(test_read_watch_t); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +typeattribute test_read_watch_t test_notify_domain; >>>>>>>>>>>>>> +typeattribute test_read_watch_t testdomain; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +allow test_read_watch_t test_notify_file_t:file >>>>>>>>>>>>>> { read write open watch watch_reads }; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Domain which CAN set any watch which CAN read accesses >>>>>>>>>>>>>> +type test_perm_read_watch_t; >>>>>>>>>>>>>> +domain_type(test_perm_read_watch_t); >>>>>>>>>>>>>> +unconfined_runs_test(test_perm_read_watch_t); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +typeattribute test_perm_read_watch_t test_notify_domain; >>>>>>>>>>>>>> +typeattribute test_perm_read_watch_t testdomain; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +allow test_perm_read_watch_t >>>>>>>>>>>>>> test_notify_file_t:file { read write open watch >>>>>>>>>>>>>> watch_with_perm watch_reads }; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Domain which CANNOT set any watches >>>>>>>>>>>>>> +type test_no_watch_t; >>>>>>>>>>>>>> +domain_type(test_no_watch_t); >>>>>>>>>>>>>> +unconfined_runs_test(test_no_watch_t); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +typeattribute test_no_watch_t test_notify_domain; >>>>>>>>>>>>>> +typeattribute test_no_watch_t testdomain; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +allow test_no_watch_t test_notify_file_t:file { read >>>>>>>>>>>>>> write open }; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Domain which has no write access but can watch >>>>>>>>>>>>>> +type test_rdonly_t; >>>>>>>>>>>>>> +domain_type(test_rdonly_t); >>>>>>>>>>>>>> +unconfined_runs_test(test_rdonly_t); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +typeattribute test_rdonly_t test_notify_domain; >>>>>>>>>>>>>> +typeattribute test_rdonly_t testdomain; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +allow test_rdonly_t test_notify_file_t:file { read open >>>>>>>>>>>>>> watch }; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +miscfiles_domain_entry_test_files(test_notify_domain); >>>>>>>>>>>>>> +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); >>>>>>>>>>>>>> diff --git a/tests/Makefile b/tests/Makefile >>>>>>>>>>>>>> index 63aa325..b99c96e 100644 >>>>>>>>>>>>>> --- a/tests/Makefile >>>>>>>>>>>>>> +++ b/tests/Makefile >>>>>>>>>>>>>> @@ -50,6 +50,10 @@ ifeq ($(shell grep >>>>>>>>>>>>>> "^SELINUX_INFINIBAND_PKEY_TEST=" >>>>>>>>>>>>>> infiniband_pkey/ibpkey_test. >>>>>>>>>>>>>> SUBDIRS += infiniband_pkey >>>>>>>>>>>>>> endif >>>>>>>>>>>>>> +ifeq ($(shell grep -q all_file_perms.*watch >>>>>>>>>>>>>> $(POLDEV)/include/support/all_perms.spt && echo >>>>>>>>>>>>>> true),true) >>>>>>>>>>>>>> +SUBDIRS+=notify >>>>>>>>>>>>>> +endif >>>>>>>>>>>>>> + >>>>>>>>>>>>>> ifeq ($(DISTRO),RHEL4) >>>>>>>>>>>>>> SUBDIRS:=$(filter-out bounds dyntrace >>>>>>>>>>>>>> dyntrans inet_socket mmap nnp_nosuid overlay >>>>>>>>>>>>>> unix_socket, $(SUBDIRS)) >>>>>>>>>>>>>> endif >>>>>>>>>>>>>> diff --git a/tests/notify/Makefile b/tests/notify/Makefile >>>>>>>>>>>>>> new file mode 100644 >>>>>>>>>>>>>> index 0000000..78c4b3b >>>>>>>>>>>>>> --- /dev/null >>>>>>>>>>>>>> +++ b/tests/notify/Makefile >>>>>>>>>>>>>> @@ -0,0 +1,5 @@ >>>>>>>>>>>>>> +TARGETS=test_inotify test_fanotify >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +all: $(TARGETS) >>>>>>>>>>>>>> +clean: >>>>>>>>>>>>>> + rm -f $(TARGETS) >>>>>>>>>>>>>> diff --git a/tests/notify/test b/tests/notify/test >>>>>>>>>>>>>> new file mode 100755 >>>>>>>>>>>>>> index 0000000..21f03de >>>>>>>>>>>>>> --- /dev/null >>>>>>>>>>>>>> +++ b/tests/notify/test >>>>>>>>>>>>>> @@ -0,0 +1,101 @@ >>>>>>>>>>>>>> +#!/usr/bin/perl >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +use Test; >>>>>>>>>>>>>> +BEGIN { plan tests => 14 } # number of tests to run >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# help the test script locate itself >>>>>>>>>>>>>> +$basedir = $0; >>>>>>>>>>>>>> +$basedir =~ s|(.*)/[^/]*|$1|; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Get rid of a testfile from last run if it's there (just >>>>>>>>>>>>>> in case) >>>>>>>>>>>>>> +system("rm -f $basedir/watch_me"); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Create a new test file >>>>>>>>>>>>>> +system("touch $basedir/watch_me"); >>>>>>>>>>>>>> +system("chcon -t test_notify_file_t $basedir/watch_me"); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +## TESTS >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +## TEST BASIC WATCH PERMISSION >>>>>>>>>>>>>> +# Should be able to set inotify watch >>>>>>>>>>>>>> +$exit_val = >>>>>>>>>>>>>> + system("runcon -t test_watch_t >>>>>>>>>>>>>> $basedir/test_inotify $basedir/watch_me 2>&1"); >>>>>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Should be able to set non-permissions based fanotify watch >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>>>>> $basedir/test_fanotify $basedir/watch_me 2>&1"); >>>>>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Should NOT be able to set permission based fanotify watch >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>>>>> $basedir/test_fanotify -p $basedir/watch_me >>>>>>>>>>>>>> 2>&1"); >>>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Should NOT be able to set read based fanotify watch >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>>>>> $basedir/test_fanotify -r $basedir/watch_me >>>>>>>>>>>>>> 2>&1"); >>>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Should NOT be able to set read based inotify watch >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>>>>> $basedir/test_inotify -r $basedir/watch_me >>>>>>>>>>>>>> 2>&1"); >>>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +## TEST PERM WATCH >>>>>>>>>>>>>> +# Should be able to set permission based fanotify watch >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> +"runcon -t test_perm_watch_t >>>>>>>>>>>>>> $basedir/test_fanotify -p $basedir/watch_me >>>>>>>>>>>>>> 2>&1" >>>>>>>>>>>>>> +); >>>>>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Should NOT be able to set watch of accesses >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> +"runcon -t test_perm_watch_t >>>>>>>>>>>>>> $basedir/test_fanotify -r $basedir/watch_me >>>>>>>>>>>>>> 2>&1" >>>>>>>>>>>>>> +); >>>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +## TEST READ NO PERM WATCH PERMSISSIONS >>>>>>>>>>>>>> +# Should NOT be able to set read and perm watch >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> +"runcon -t test_read_watch_t >>>>>>>>>>>>>> $basedir/test_fanotify -p -r $basedir/watch_me >>>>>>>>>>>>>> 2>&1" >>>>>>>>>>>>>> +); >>>>>>>>>>>>>> +ok($exit_val); # should fail >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Should be able to set read inotify watch >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> +"runcon -t test_read_watch_t >>>>>>>>>>>>>> $basedir/test_inotify -r $basedir/watch_me 2>&1" >>>>>>>>>>>>>> +); >>>>>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +## TEST READ WITH PERM WATCH PERMSISSIONS >>>>>>>>>>>>>> +# Should be able to set read and perm watch >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> +"runcon -t test_perm_read_watch_t >>>>>>>>>>>>>> $basedir/test_fanotify -p -r $basedir/watch_me >>>>>>>>>>>>>> 2>&1" >>>>>>>>>>>>>> +); >>>>>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +## TEST NO WATCH PERMSISSIONS >>>>>>>>>>>>>> +# Should NOT be able to set inotify watch >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> + "runcon -t test_no_watch_t >>>>>>>>>>>>>> $basedir/test_inotify $basedir/watch_me 2>&1"); >>>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Should NOT be able to set any fanotify watch >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> + "runcon -t test_no_watch_t >>>>>>>>>>>>>> $basedir/test_fanotify $basedir/watch_me 2>&1"); >>>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +## TEST READ ONLY >>>>>>>>>>>>>> +# Should NOT be able to get read-write descriptor >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> + "runcon -t test_rdonly_t >>>>>>>>>>>>>> $basedir/test_fanotify -l $basedir/watch_me >>>>>>>>>>>>>> 2>&1"); >>>>>>>>>>>>>> +ok($exit_val); # this should fail >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Should be able to get read-write descriptor >>>>>>>>>>>>>> +$exit_val = system( >>>>>>>>>>>>>> + "runcon -t test_watch_t >>>>>>>>>>>>>> $basedir/test_fanotify -l $basedir/watch_me >>>>>>>>>>>>>> 2>&1"); >>>>>>>>>>>>>> +ok( $exit_val, 0 ); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +# Clean up test file >>>>>>>>>>>>>> +system("rm -f $basedir/watch_me"); >>>>>>>>>>>>>> diff --git a/tests/notify/test_fanotify.c >>>>>>>>>>>>>> b/tests/notify/test_fanotify.c >>>>>>>>>>>>>> new file mode 100644 >>>>>>>>>>>>>> index 0000000..fff773f >>>>>>>>>>>>>> --- /dev/null >>>>>>>>>>>>>> +++ b/tests/notify/test_fanotify.c >>>>>>>>>>>>>> @@ -0,0 +1,105 @@ >>>>>>>>>>>>>> +#define _GNU_SOURCE 1 >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +#include <stdio.h> >>>>>>>>>>>>>> +#include <stdlib.h> >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +#include <getopt.h> >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +#include <fcntl.h> >>>>>>>>>>>>>> +#include <poll.h> >>>>>>>>>>>>>> +#include <sys/fanotify.h> >>>>>>>>>>>>>> +#include <unistd.h> >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +void printUsage() >>>>>>>>>>>>>> +{ >>>>>>>>>>>>>> + fprintf(stderr, "Usage: test_fanotify [-p] >>>>>>>>>>>>>> [-r] [-l] file_name\n"); >>>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>>> +} >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +int main(int argc, char *argv[]) >>>>>>>>>>>>>> +{ >>>>>>>>>>>>>> + if (argc < 2) { >>>>>>>>>>>>>> + printUsage(); >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + int fd, ret, arg; >>>>>>>>>>>>>> + int mask = FAN_OPEN; // default mask >>>>>>>>>>>>>> + int listening = 0; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + // the -p flag will test for watch_with_perm >>>>>>>>>>>>>> + // the mask used at mark will contain FAN_OPEN_PERM >>>>>>>>>>>>>> + // >>>>>>>>>>>>>> + // the -r flag will test for watching >>>>>>>>>>>>>> accesses to files for reads >>>>>>>>>>>>>> + // the mask will contain FAN_ACCESS >>>>>>>>>>>>>> + while ((arg = getopt(argc, argv, "prl")) != -1) { >>>>>>>>>>>>>> + switch (arg) { >>>>>>>>>>>>>> + case 'p': >>>>>>>>>>>>>> + mask |= FAN_OPEN_PERM; >>>>>>>>>>>>>> + break; >>>>>>>>>>>>>> + case 'r': >>>>>>>>>>>>>> + mask |= FAN_ACCESS; >>>>>>>>>>>>>> + break; >>>>>>>>>>>>>> + case 'l': >>>>>>>>>>>>>> + listening = 1; >>>>>>>>>>>>>> + break; >>>>>>>>>>>>>> + default: >>>>>>>>>>>>>> + printUsage(); >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + // get file descriptor for new fanotify event queue >>>>>>>>>>>>>> + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); >>>>>>>>>>>>>> + if (fd < 0) { >>>>>>>>>>>>>> + perror("fanotify_init:bad file descriptor"); >>>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + // mark a filesystem object and add mark to event queue >>>>>>>>>>>>>> + // get notifications on file opens, accesses, and closes >>>>>>>>>>>>>> + // use current working directory as base dir >>>>>>>>>>>>>> + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, >>>>>>>>>>>>>> AT_FDCWD, argv[optind]); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + if (ret < 0) { >>>>>>>>>>>>>> + perror("test_fanotify:watch denied"); >>>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + // logic to actually listen for an event if >>>>>>>>>>>>>> the -l flag is passed >>>>>>>>>>>>>> + // this is used to test if an app with >>>>>>>>>>>>>> read-only access can get a read/write >>>>>>>>>>>>>> + // handle to the watched file >>>>>>>>>>>>>> + if (listening) { >>>>>>>>>>>>>> + if (fork() == 0) { // fork a child >>>>>>>>>>>>>> process to cause an event on the file >>>>>>>>>>>>>> + FILE *f; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + f = fopen(argv[optind], "r"); // open file >>>>>>>>>>>>>> for reading >>>>>>>>>>>>>> + fgetc(f); // read char >>>>>>>>>>>>>> from file >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + fclose(f); >>>>>>>>>>>>>> + } else { // logic to watch for events >>>>>>>>>>>>>> and try to access file read/write >>>>>>>>>>>>>> + struct pollfd fds; >>>>>>>>>>>>>> + fds.fd = fd; >>>>>>>>>>>>>> + fds.events = POLLIN; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + while (listening) { >>>>>>>>>>>>>> + int polled = poll(&fds, 1, 1); >>>>>>>>>>>>>> + if (polled > 0) { >>>>>>>>>>>>>> + if (fds.revents & POLLIN) { >>>>>>>>>>>>>> + struct fanotify_event_metadata >>>>>>>>>>>>>> buff[200]; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + size_t len = read(fd, >>>>>>>>>>>>>> (void *)&buff, sizeof(buff)); >>>>>>>>>>>>>> + if (len == -1) { >>>>>>>>>>>>>> + >>>>>>>>>>>>>> perror("test_fanotify:can't open file"); >>>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>>> + } else { >>>>>>>>>>>>>> + listening = 0; >>>>>>>>>>>>>> + break; >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + } else if (polled == -1) { >>>>>>>>>>>>>> + listening = 0; >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + exit(0); >>>>>>>>>>>>>> +} >>>>>>>>>>>>>> diff --git a/tests/notify/test_inotify.c >>>>>>>>>>>>>> b/tests/notify/test_inotify.c >>>>>>>>>>>>>> new file mode 100644 >>>>>>>>>>>>>> index 0000000..17c3565 >>>>>>>>>>>>>> --- /dev/null >>>>>>>>>>>>>> +++ b/tests/notify/test_inotify.c >>>>>>>>>>>>>> @@ -0,0 +1,43 @@ >>>>>>>>>>>>>> +#include <stdio.h> >>>>>>>>>>>>>> +#include <stdlib.h> >>>>>>>>>>>>>> +#include <sys/inotify.h> >>>>>>>>>>>>>> +#include <getopt.h> >>>>>>>>>>>>>> + >>>>>>>>>>>>>> +int main(int argc, char *argv[]) >>>>>>>>>>>>>> +{ >>>>>>>>>>>>>> + if (argc < 2) { >>>>>>>>>>>>>> + fprintf(stderr, "Usage: test_inotify [-r] >>>>>>>>>>>>>> file_name\n"); >>>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + int fd, wd, arg; >>>>>>>>>>>>>> + int mask = IN_MODIFY; >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + while ((arg = getopt(argc, argv, "pr")) != -1) { >>>>>>>>>>>>>> + switch (arg) { >>>>>>>>>>>>>> + case 'r': >>>>>>>>>>>>>> + mask |= IN_ACCESS; >>>>>>>>>>>>>> + break; >>>>>>>>>>>>>> + default: >>>>>>>>>>>>>> + fprintf(stderr, "Usage: >>>>>>>>>>>>>> test_inotify [-r] file_name\n"); >>>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + // get new file descriptor for inotify access >>>>>>>>>>>>>> + fd = inotify_init(); >>>>>>>>>>>>>> + if (fd < 0) { >>>>>>>>>>>>>> + perror("inotify_init:bad file descriptor"); >>>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + // set watch on file and get watch >>>>>>>>>>>>>> descriptor for accessing events on it >>>>>>>>>>>>>> + wd = inotify_add_watch(fd, argv[optind], mask); >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + if (wd < 0) { >>>>>>>>>>>>>> + perror("test_inotify:watch denied"); >>>>>>>>>>>>>> + exit(1); >>>>>>>>>>>>>> + } >>>>>>>>>>>>>> + >>>>>>>>>>>>>> + exit(0); >>>>>>>>>>>>>> +} >>>>>>>>>>>>>> -- >>>>>>>>>>>>>> 2.21.0 >>>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> >
On Tue, Sep 10, 2019 at 03:55:46PM -0400, Stephen Smalley wrote: > On 9/10/19 3:45 PM, Stephen Smalley wrote: > > On 9/10/19 2:20 PM, Dominick Grift wrote: > > > On Tue, Sep 10, 2019 at 02:13:07PM -0400, Stephen Smalley wrote: > > > > On 9/10/19 12:32 PM, Dominick Grift wrote: > > > > > On Tue, Sep 10, 2019 at 12:25:44PM -0400, Stephen Smalley wrote: > > > > > > On 9/10/19 11:22 AM, Dominick Grift wrote: > > > > > > > On Tue, Sep 10, 2019 at 11:02:16AM -0400, Stephen Smalley wrote: > > > > > > > > On 9/10/19 10:59 AM, Stephen Smalley wrote: > > > > > > > > > On 9/10/19 10:54 AM, Stephen Smalley wrote: > > > > > > > > > > On 9/10/19 10:40 AM, Stephen Smalley wrote: > > > > > > > > > > > On 9/10/19 10:15 AM, Dominick Grift wrote: > > > > > > > > > > > > On Tue, Sep 10, 2019 at 08:26:57AM -0400, Stephen Smalley wrote: > > > > > > > > > > > > > On 9/10/19 1:59 AM, Dominick Grift wrote: > > > > > > > > > > > > > > On Wed, Jul 10, 2019 at 09:39:17AM -0400, Aaron Goidel wrote: > > > > > > > > > > > > > > > Added a suite to test permissions for setting > > > > > > > > > > > > > > > inotify and fanotify watches > > > > > > > > > > > > > > > on filesystem objects. Tests watch, > > > > > > > > > > > > > > > watch_with_perm, and watch_reads permissions. > > > > > > > > > > > > > > > > > > > > > > > > > > > > Ive also "tested" the fsnotify patch. And my tests > > > > > > > > > > > > > > indicate that this might cause issues: > > > > > > > > > > > > > > > > > > > > > > > > > > > > I added the access vectors to my policy, but on > > > > > > > > > > > > > > older systems (debian 10) cron fails to start > > > > > > > > > > > > > > cron needs the "entrypoint" permission on > > > > > > > > > > > > > > /etc/crontab but it looks like appending the "watch" > > > > > > > > > > > > > > access vectors to common-file disrupted the ordering > > > > > > > > > > > > > > The result is that now i have to allow cron to > > > > > > > > > > > > > > "watch_read" /etc/crontab even though the neither > > > > > > > > > > > > > > kernel nor selinux user space are aware of the > > > > > > > > > > > > > > fsnotify access vectors > > > > > > > > > > > > > > It seems the cron selinux code got confused and now > > > > > > > > > > > > > > thinks watch_read is entrypoint (its using selinux > > > > > > > > > > > > > > code to determine whether it can manually transition > > > > > > > > > > > > > > to cronjob domains on crontabs) > > > > > > > > > > > > > > > > > > > > > > > > > > > > I am hoping this issue with resolve itself on > > > > > > > > > > > > > > systems with kernels and user spaces that suppose > > > > > > > > > > > > > > fsnotify. > > > > > > > > > > > > > > However unless i am overlooking something this is > > > > > > > > > > > > > > still likely to disrupt compatibility > > > > > > > > > > > > > > > > > > > > > > > > > > So, IIUC, the issue is that: > > > > > > > > > > > > > a) older cron was directly using the fixed > > > > > > > > > > > > > FILE__ENTRYPOINT definition from > > > > > > > > > > > > > libselinux in a security_compute_av() call rather than > > > > > > > > > > > > > dynamically looking > > > > > > > > > > > > > up entrypoint permission, > > > > > > > > > > > > > b) the value of the file entrypoint permission in policy > > > > > > > > > > > > > has changed because > > > > > > > > > > > > > you updated your policy and chose to place the watch* > > > > > > > > > > > > > permissions in the > > > > > > > > > > > > > common file definition to match the kernel. > > > > > > > > > > > > > > > > > > > > > > > > > > Note that you could have instead sprinkled copies of the > > > > > > > > > > > > > watch* permissions > > > > > > > > > > > > > across all of the individual file/dir/*_file classes and > > > > > > > > > > > > > placed them at the > > > > > > > > > > > > > end of the classes if you wanted to avoid this > > > > > > > > > > > > > compatibility issue. The > > > > > > > > > > > > > policy and kernel definitions no longer need to be > > > > > > > > > > > > > identical; the kernel > > > > > > > > > > > > > will dynamically map between > > > > > > > > > > > > > them for its own permission > > > > > > > > > > > > > checks. > > > > > > > > > > > > > > > > > > > > > > > > > > Also, this should have already been broken for you when > > > > > > > > > > > > > map permission was > > > > > > > > > > > > > added, which would have shown up as execute_no_trans > > > > > > > > > > > > > being checked instead > > > > > > > > > > > > > of entrypoint. This was already filed as a bug on cron > > > > > > > > > > > > > in debian here: > > > > > > > > > > > > > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924716 > > > > > > > > > > > > > > > > > > > > > > > > > > So, wrt compatibility, IIUC: > > > > > > > > > > > > > - the kernel change does not > > > > > > > > > > > > > break compatibility for old > > > > > > > > > > > > > policy + old > > > > > > > > > > > > > userspace, > > > > > > > > > > > > > - new policy can choose to add the new permissions in a > > > > > > > > > > > > > backward-compatible > > > > > > > > > > > > > manner if desired, although refpolicy has already chosen > > > > > > > > > > > > > not to do this for > > > > > > > > > > > > > map permission, > > > > > > > > > > > > > - the offending code in cron produces build warnings > > > > > > > > > > > > > that were introduced in > > > > > > > > > > > > > 2014 in libselinux to update > > > > > > > > > > > > > their code to use the > > > > > > > > > > > > > dynamic class/perm > > > > > > > > > > > > > mapping support, which would resolve the issue. > > > > > > > > > > > > > > > > > > > > > > > > this does not work (cron[8934]: > > > > > > > > > > > > ((null)) ENTRYPOINT FAILED): https://defensec.nl/gitweb/dssp2.git/commitdiff/914b1d5366922f92435cba780519c5d2bb9f4f7d > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -x > > > > > > > > > > > > --common common_file > > > > > > > > > > > > > > > > > > > > > > > > Commons: 1 > > > > > > > > > > > > common common_file > > > > > > > > > > > > { > > > > > > > > > > > > append > > > > > > > > > > > > lock > > > > > > > > > > > > mounton > > > > > > > > > > > > unlink > > > > > > > > > > > > read > > > > > > > > > > > > create > > > > > > > > > > > > quotaon > > > > > > > > > > > > execute > > > > > > > > > > > > setattr > > > > > > > > > > > > map > > > > > > > > > > > > relabelto > > > > > > > > > > > > rename > > > > > > > > > > > > link > > > > > > > > > > > > ioctl > > > > > > > > > > > > getattr > > > > > > > > > > > > relabelfrom > > > > > > > > > > > > } > > > > > > > > > > > > [kcinimod@brutus dssp2 (master=)]$ seinfo policy.31 -xcfile > > > > > > > > > > > > > > > > > > > > > > > > Classes: 1 > > > > > > > > > > > > class file > > > > > > > > > > > > inherits common_file > > > > > > > > > > > > { > > > > > > > > > > > > execmod > > > > > > > > > > > > watch > > > > > > > > > > > > write > > > > > > > > > > > > watch_reads > > > > > > > > > > > > execute_no_trans > > > > > > > > > > > > watch_mount > > > > > > > > > > > > watch_with_perm > > > > > > > > > > > > open > > > > > > > > > > > > watch_sb > > > > > > > > > > > > audit_access > > > > > > > > > > > > entrypoint > > > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > > > If you want to preserve compatibility with userspace using fixed > > > > > > > > > > > definitions of FILE__ENTRYPOINT, then you have to insert any new > > > > > > > > > > > file permissions after the current entrypoint permission in the > > > > > > > > > > > class file. So watch and friends have to go after it, not before > > > > > > > > > > > it. > > > > > > > > > > > > > > > > > > > > > > Also, since the kernel always uses FILE__WATCH* in the check > > > > > > > > > > > code rather than distinguishing by class, the watch* permissions > > > > > > > > > > > need to be at the same offset in all of the file classes. The > > > > > > > > > > > same is true of the other file permissions. It looks like you > > > > > > > > > > > may have other permissions out of sync across the file classes > > > > > > > > > > > e.g. execmod, open, audit_access, that need to be aligned or the > > > > > > > > > > > kernel could check the wrong permission. > > > > > > > > > > > > > > > > > > > > Sorry, the last para isn't correct - it > > > > > > > > > > should get mapped correctly > > > > > > > > > > per class. But you do need to add the > > > > > > > > > > permissions after entrypoint > > > > > > > > > > in the file class to avoid displacing its value. > > > > > > > > > > > > > > > > > > Also, it looks like your file class > > > > > > > > > permission order differs in other > > > > > > > > > incompatible ways. If you want it to be > > > > > > > > > compatible with the deprecated > > > > > > > > > libselinux headers, the requisite order would be: > > > > > > > > > class file > > > > > > > > > inherits common_file > > > > > > > > > { > > > > > > > > > execute_no_trans > > > > > > > > > entrypoint > > > > > > > > > execmod > > > > > > > > > open > > > > > > > > > audit_access > > > > > > > > > map > > > > > > > > > > > > > > > > Sorry, insert watch* permissions here. > > > > > > > > > > > > > > I applied brute force: > > > > > > > > > > > > > > the map permission can be part of common_file just fine. > > > > > > > the audit_access av (which was clearly introduced > > > > > > > after entrypoint can precede entrypoint just fine. > > > > > > > > > > > > > > The problem is the prescence of the fsnotify access > > > > > > > vector in general. Moving them out of common_file > > > > > > > and after entrypoint does not make a difference. > > > > > > > As soon as I remove the fsnotify av's things start to work. > > > > > > > > > > > > > > In other words. besides the precensce of the > > > > > > > fsnotify access vectors everything (seemingly) is in > > > > > > > order > > > > > > > Now for me the question remains: will this issue > > > > > > > automatically resolve itself as soon as userspace > > > > > > > and kernel support the fsnotify av > > > > > > > > > > > > That doesn't make any sense to me. Sounds like a bug > > > > > > somewhere. Anything > > > > > > that changes the permission bit value in the policy for > > > > > > FILE__ENTRYPOINT is > > > > > > going to break legacy crond that is using the hardcoded value from the > > > > > > deprecated libselinux headers. So adding permissions at > > > > > > the end of the file > > > > > > class should be fine. Adding or removing to/from common > > > > > > file should break. > > > > > > I can't explain the behavior you are seeing. > > > > > > > > > > It does not make sense to me either, but i believe it when i see it. > > > > > Ive tried several times and just removing the fsnotify > > > > > access vectors make it work. Whether i append them to > > > > > common_file or whether i append them to the individual > > > > > classes does not make a difference. > > > > > > > > > > BTW: this fixes it for me: https://lore.kernel.org/selinux/d706a78c-d6d0-13bb-c9af-7ec4365b9b44@debian.org/T/#u > > > > > > > > > > > > > I don't suppose you could make the broken policy available > > > > somewhere? Source > > > > and a binary. > > > > > > huh? git clone git://defensec.nl/dssp2.git && cd dssp2 && make all > > > > If I build that policy, then the resulting policy yields the following > > values for the watch* and subsequent permissions: > > 0x00010000 watch > > 0x00020000 watch_mount > > 0x00040000 watch_reads > > 0x00080000 watch_sb > > 0x00100000 watch_with_perm > > 0x00200000 write > > 0x00400000 audit_access > > 0x00800000 entrypoint > > 0x01000000 execmod > > 0x02000000 execute_no_trans > > 0x04000000 open > > > > You can see this yourself with the attached program. > > > > Contrast that with the deprecated definitions in > > /usr/include/selinux/av_permissions.h that were generated from the old > > refpolicy access_vectors file long ago: > > #define FILE__MOUNTON 0x00010000UL > > #define FILE__EXECUTE_NO_TRANS 0x00020000UL > > #define FILE__ENTRYPOINT 0x00040000UL > > #define FILE__EXECMOD 0x00080000UL > > #define FILE__OPEN 0x00100000UL > > > > So when cron tries to check FILE__ENTRYPOINT, it ends up checking the > > bit for watch_reads instead. > > > > In order to avoid this, you would need to synchronize your common_file > > and file definitions to ensure that your policy still defines entrypoint > > with the same value. This is what I was trying to achieve by > > recommending moving the watch* permissions and map permission to the end > > of the classes. However, what I didn't realize was that you have made > > multiple other changes to your common_file and file definitions that > > have perturbed the values in other ways, e.g. you removed swapon > > (thereby shifting back the values, effectively canceling out the > > addition of map, such that moving map now actually yields an incorrect > > entrypoint value). And while you did move audit_access in front of > > entrypoint in the class file definition, it was already the case that > > entrypoint was second in the list originally (the first used to be > > execute_no_trans until you sorted them). > > > > If I apply the attached change to merely move the watch permissions, > > then the correct value is assigned to entrypoint and everything should > > work even without the cron patch. > > > > All that said, I think the cron patch is the right fix - I just wanted > > to understand what was happening here, which I think I now do. > > Also, looking at your git history, your earlier attempt to move just the > watch permissions was broken because it also moved the "write" permission > along with it, thereby shifting the class file permission values back one > too many. Yes, i corrected that later. I also made changes that didnt make it into git Thanks for helping demysitify some of this. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> > > > > > > > > > > > > > > > --- > > > > > > > > > > > > > > > policy/Makefile | 4 ++ > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > policy/test_notify.te > > > > > > > > > > > > > > > | 74 > > > > > > > > > > > > > > > ++++++++++++++++++++++++ > > > > > > > > > > > > > > > tests/Makefile | 4 ++ > > > > > > > > > > > > > > > tests/notify/Makefile | 5 ++ > > > > > > > > > > > > > > > tests/notify/test | 101 > > > > > > > > > > > > > > > +++++++++++++++++++++++++++++++++ > > > > > > > > > > > > > > > tests/notify/test_fanotify.c | 105 > > > > > > > > > > > > > > > +++++++++++++++++++++++++++++++++++ > > > > > > > > > > > > > > > tests/notify/test_inotify.c | 43 ++++++++++++++ > > > > > > > > > > > > > > > 7 files changed, 336 insertions(+) > > > > > > > > > > > > > > > create mode 100644 policy/test_notify.te > > > > > > > > > > > > > > > create mode 100644 tests/notify/Makefile > > > > > > > > > > > > > > > create mode 100755 tests/notify/test > > > > > > > > > > > > > > > create mode 100644 tests/notify/test_fanotify.c > > > > > > > > > > > > > > > create mode 100644 tests/notify/test_inotify.c > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > diff --git a/policy/Makefile b/policy/Makefile > > > > > > > > > > > > > > > index 305b572..65f88c5 100644 > > > > > > > > > > > > > > > --- a/policy/Makefile > > > > > > > > > > > > > > > +++ b/policy/Makefile > > > > > > > > > > > > > > > @@ -71,6 +71,10 @@ ifeq ($(shell grep -q > > > > > > > > > > > > > > > corenet_sctp_bind_all_nodes > > > > > > > > > > > > > > > $(POLDEV)/include/kernel/coren > > > > > > > > > > > > > > > TARGETS += test_sctp.te > > > > > > > > > > > > > > > endif > > > > > > > > > > > > > > > +ifeq ($(shell grep -q all_file_perms.*watch > > > > > > > > > > > > > > > $(POLDEV)/include/support/all_perms.spt && echo > > > > > > > > > > > > > > > true),true) > > > > > > > > > > > > > > > +TARGETS+=test_notify.te > > > > > > > > > > > > > > > +endif > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > ifeq > > > > > > > > > > > > > > > (x$(DISTRO),$(filter > > > > > > > > > > > > > > > x$(DISTRO),xRHEL4 > > > > > > > > > > > > > > > xRHEL5 xRHEL6)) > > > > > > > > > > > > > > > TARGETS:=$(filter-out test_overlayfs.te > > > > > > > > > > > > > > > test_mqueue.te, $(TARGETS)) > > > > > > > > > > > > > > > endif > > > > > > > > > > > > > > > diff --git a/policy/test_notify.te b/policy/test_notify.te > > > > > > > > > > > > > > > new file mode 100644 > > > > > > > > > > > > > > > index 0000000..8ba6f1a > > > > > > > > > > > > > > > --- /dev/null > > > > > > > > > > > > > > > +++ b/policy/test_notify.te > > > > > > > > > > > > > > > @@ -0,0 +1,74 @@ > > > > > > > > > > > > > > > +#################################################### > > > > > > > > > > > > > > > +# Policy for testing inoftify and fanotify watches # > > > > > > > > > > > > > > > +#################################################### > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +attribute test_notify_domain; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Type for the file on which we want to set a watch > > > > > > > > > > > > > > > +type test_notify_file_t; > > > > > > > > > > > > > > > +files_type(test_notify_file_t); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Domain for the > > > > > > > > > > > > > > > process which CAN > > > > > > > > > > > > > > > set a non-permission > > > > > > > > > > > > > > > watch > > > > > > > > > > > > > > > +type test_watch_t; > > > > > > > > > > > > > > > +domain_type(test_watch_t); > > > > > > > > > > > > > > > +unconfined_runs_test(test_watch_t); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +typeattribute test_watch_t test_notify_domain; > > > > > > > > > > > > > > > +typeattribute test_watch_t testdomain; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +allow test_notify_domain self:capability sys_admin; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +allow test_watch_t test_notify_file_t:file { > > > > > > > > > > > > > > > read write open watch }; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Domain for the > > > > > > > > > > > > > > > process which CAN > > > > > > > > > > > > > > > set a NON-access > > > > > > > > > > > > > > > watch on a file > > > > > > > > > > > > > > > +type test_perm_watch_t; > > > > > > > > > > > > > > > +domain_type(test_perm_watch_t); > > > > > > > > > > > > > > > +unconfined_runs_test(test_perm_watch_t); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +typeattribute test_perm_watch_t test_notify_domain; > > > > > > > > > > > > > > > +typeattribute test_perm_watch_t testdomain; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +allow test_perm_watch_t test_notify_file_t:file > > > > > > > > > > > > > > > { read write open watch watch_with_perm }; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Domain which CAN > > > > > > > > > > > > > > > set a NON-perm watch > > > > > > > > > > > > > > > which MAY read > > > > > > > > > > > > > > > accesses > > > > > > > > > > > > > > > +type test_read_watch_t; > > > > > > > > > > > > > > > +domain_type(test_read_watch_t); > > > > > > > > > > > > > > > +unconfined_runs_test(test_read_watch_t); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +typeattribute test_read_watch_t test_notify_domain; > > > > > > > > > > > > > > > +typeattribute test_read_watch_t testdomain; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +allow test_read_watch_t test_notify_file_t:file > > > > > > > > > > > > > > > { read write open watch watch_reads }; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Domain which CAN set any watch which CAN read accesses > > > > > > > > > > > > > > > +type test_perm_read_watch_t; > > > > > > > > > > > > > > > +domain_type(test_perm_read_watch_t); > > > > > > > > > > > > > > > +unconfined_runs_test(test_perm_read_watch_t); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +typeattribute test_perm_read_watch_t test_notify_domain; > > > > > > > > > > > > > > > +typeattribute test_perm_read_watch_t testdomain; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +allow test_perm_read_watch_t > > > > > > > > > > > > > > > test_notify_file_t:file { read write open watch > > > > > > > > > > > > > > > watch_with_perm watch_reads }; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Domain which CANNOT set any watches > > > > > > > > > > > > > > > +type test_no_watch_t; > > > > > > > > > > > > > > > +domain_type(test_no_watch_t); > > > > > > > > > > > > > > > +unconfined_runs_test(test_no_watch_t); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +typeattribute test_no_watch_t test_notify_domain; > > > > > > > > > > > > > > > +typeattribute test_no_watch_t testdomain; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +allow > > > > > > > > > > > > > > > test_no_watch_t > > > > > > > > > > > > > > > test_notify_file_t:file > > > > > > > > > > > > > > > { read write open }; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Domain which has no write access but can watch > > > > > > > > > > > > > > > +type test_rdonly_t; > > > > > > > > > > > > > > > +domain_type(test_rdonly_t); > > > > > > > > > > > > > > > +unconfined_runs_test(test_rdonly_t); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +typeattribute test_rdonly_t test_notify_domain; > > > > > > > > > > > > > > > +typeattribute test_rdonly_t testdomain; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +allow test_rdonly_t > > > > > > > > > > > > > > > test_notify_file_t:file > > > > > > > > > > > > > > > { read open watch }; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +miscfiles_domain_entry_test_files(test_notify_domain); > > > > > > > > > > > > > > > +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); > > > > > > > > > > > > > > > diff --git a/tests/Makefile b/tests/Makefile > > > > > > > > > > > > > > > index 63aa325..b99c96e 100644 > > > > > > > > > > > > > > > --- a/tests/Makefile > > > > > > > > > > > > > > > +++ b/tests/Makefile > > > > > > > > > > > > > > > @@ -50,6 +50,10 @@ ifeq ($(shell grep > > > > > > > > > > > > > > > "^SELINUX_INFINIBAND_PKEY_TEST=" > > > > > > > > > > > > > > > infiniband_pkey/ibpkey_test. > > > > > > > > > > > > > > > SUBDIRS += infiniband_pkey > > > > > > > > > > > > > > > endif > > > > > > > > > > > > > > > +ifeq ($(shell grep -q all_file_perms.*watch > > > > > > > > > > > > > > > $(POLDEV)/include/support/all_perms.spt && echo > > > > > > > > > > > > > > > true),true) > > > > > > > > > > > > > > > +SUBDIRS+=notify > > > > > > > > > > > > > > > +endif > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > ifeq ($(DISTRO),RHEL4) > > > > > > > > > > > > > > > SUBDIRS:=$(filter-out bounds dyntrace > > > > > > > > > > > > > > > dyntrans inet_socket mmap nnp_nosuid overlay > > > > > > > > > > > > > > > unix_socket, $(SUBDIRS)) > > > > > > > > > > > > > > > endif > > > > > > > > > > > > > > > diff --git a/tests/notify/Makefile b/tests/notify/Makefile > > > > > > > > > > > > > > > new file mode 100644 > > > > > > > > > > > > > > > index 0000000..78c4b3b > > > > > > > > > > > > > > > --- /dev/null > > > > > > > > > > > > > > > +++ b/tests/notify/Makefile > > > > > > > > > > > > > > > @@ -0,0 +1,5 @@ > > > > > > > > > > > > > > > +TARGETS=test_inotify test_fanotify > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +all: $(TARGETS) > > > > > > > > > > > > > > > +clean: > > > > > > > > > > > > > > > + rm -f $(TARGETS) > > > > > > > > > > > > > > > diff --git a/tests/notify/test b/tests/notify/test > > > > > > > > > > > > > > > new file mode 100755 > > > > > > > > > > > > > > > index 0000000..21f03de > > > > > > > > > > > > > > > --- /dev/null > > > > > > > > > > > > > > > +++ b/tests/notify/test > > > > > > > > > > > > > > > @@ -0,0 +1,101 @@ > > > > > > > > > > > > > > > +#!/usr/bin/perl > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +use Test; > > > > > > > > > > > > > > > +BEGIN { plan tests => 14 } # number of tests to run > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# help the test script locate itself > > > > > > > > > > > > > > > +$basedir = $0; > > > > > > > > > > > > > > > +$basedir =~ s|(.*)/[^/]*|$1|; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Get rid of a > > > > > > > > > > > > > > > testfile from last > > > > > > > > > > > > > > > run if it's there > > > > > > > > > > > > > > > (just in case) > > > > > > > > > > > > > > > +system("rm -f $basedir/watch_me"); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Create a new test file > > > > > > > > > > > > > > > +system("touch $basedir/watch_me"); > > > > > > > > > > > > > > > +system("chcon -t test_notify_file_t $basedir/watch_me"); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +## TESTS > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +## TEST BASIC WATCH PERMISSION > > > > > > > > > > > > > > > +# Should be able to set inotify watch > > > > > > > > > > > > > > > +$exit_val = > > > > > > > > > > > > > > > + system("runcon -t test_watch_t > > > > > > > > > > > > > > > $basedir/test_inotify $basedir/watch_me 2>&1"); > > > > > > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Should be able to set non-permissions based fanotify watch > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > > > > > > $basedir/test_fanotify $basedir/watch_me 2>&1"); > > > > > > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Should NOT be able to set permission based fanotify watch > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > > > > > > $basedir/test_fanotify -p $basedir/watch_me > > > > > > > > > > > > > > > 2>&1"); > > > > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Should NOT be able to set read based fanotify watch > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > > > > > > $basedir/test_fanotify -r $basedir/watch_me > > > > > > > > > > > > > > > 2>&1"); > > > > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Should NOT be able to set read based inotify watch > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > > > > > > $basedir/test_inotify -r $basedir/watch_me > > > > > > > > > > > > > > > 2>&1"); > > > > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +## TEST PERM WATCH > > > > > > > > > > > > > > > +# Should be able to set permission based fanotify watch > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > +"runcon -t test_perm_watch_t > > > > > > > > > > > > > > > $basedir/test_fanotify -p $basedir/watch_me > > > > > > > > > > > > > > > 2>&1" > > > > > > > > > > > > > > > +); > > > > > > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Should NOT be able to set watch of accesses > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > +"runcon -t test_perm_watch_t > > > > > > > > > > > > > > > $basedir/test_fanotify -r $basedir/watch_me > > > > > > > > > > > > > > > 2>&1" > > > > > > > > > > > > > > > +); > > > > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +## TEST READ NO PERM WATCH PERMSISSIONS > > > > > > > > > > > > > > > +# Should NOT be able to set read and perm watch > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > +"runcon -t test_read_watch_t > > > > > > > > > > > > > > > $basedir/test_fanotify -p -r $basedir/watch_me > > > > > > > > > > > > > > > 2>&1" > > > > > > > > > > > > > > > +); > > > > > > > > > > > > > > > +ok($exit_val); # should fail > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Should be able to set read inotify watch > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > +"runcon -t test_read_watch_t > > > > > > > > > > > > > > > $basedir/test_inotify -r $basedir/watch_me 2>&1" > > > > > > > > > > > > > > > +); > > > > > > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +## TEST READ WITH PERM WATCH PERMSISSIONS > > > > > > > > > > > > > > > +# Should be able to set read and perm watch > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > +"runcon -t test_perm_read_watch_t > > > > > > > > > > > > > > > $basedir/test_fanotify -p -r $basedir/watch_me > > > > > > > > > > > > > > > 2>&1" > > > > > > > > > > > > > > > +); > > > > > > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +## TEST NO WATCH PERMSISSIONS > > > > > > > > > > > > > > > +# Should NOT be able to set inotify watch > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > + "runcon -t test_no_watch_t > > > > > > > > > > > > > > > $basedir/test_inotify $basedir/watch_me 2>&1"); > > > > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Should NOT be able to set any fanotify watch > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > + "runcon -t test_no_watch_t > > > > > > > > > > > > > > > $basedir/test_fanotify $basedir/watch_me 2>&1"); > > > > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +## TEST READ ONLY > > > > > > > > > > > > > > > +# Should NOT be able to get read-write descriptor > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > + "runcon -t test_rdonly_t > > > > > > > > > > > > > > > $basedir/test_fanotify -l $basedir/watch_me > > > > > > > > > > > > > > > 2>&1"); > > > > > > > > > > > > > > > +ok($exit_val); # this should fail > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Should be able to get read-write descriptor > > > > > > > > > > > > > > > +$exit_val = system( > > > > > > > > > > > > > > > + "runcon -t test_watch_t > > > > > > > > > > > > > > > $basedir/test_fanotify -l $basedir/watch_me > > > > > > > > > > > > > > > 2>&1"); > > > > > > > > > > > > > > > +ok( $exit_val, 0 ); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +# Clean up test file > > > > > > > > > > > > > > > +system("rm -f $basedir/watch_me"); > > > > > > > > > > > > > > > diff --git a/tests/notify/test_fanotify.c > > > > > > > > > > > > > > > b/tests/notify/test_fanotify.c > > > > > > > > > > > > > > > new file mode 100644 > > > > > > > > > > > > > > > index 0000000..fff773f > > > > > > > > > > > > > > > --- /dev/null > > > > > > > > > > > > > > > +++ b/tests/notify/test_fanotify.c > > > > > > > > > > > > > > > @@ -0,0 +1,105 @@ > > > > > > > > > > > > > > > +#define _GNU_SOURCE 1 > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +#include <stdio.h> > > > > > > > > > > > > > > > +#include <stdlib.h> > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +#include <getopt.h> > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +#include <fcntl.h> > > > > > > > > > > > > > > > +#include <poll.h> > > > > > > > > > > > > > > > +#include <sys/fanotify.h> > > > > > > > > > > > > > > > +#include <unistd.h> > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +void printUsage() > > > > > > > > > > > > > > > +{ > > > > > > > > > > > > > > > + fprintf(stderr, "Usage: test_fanotify [-p] > > > > > > > > > > > > > > > [-r] [-l] file_name\n"); > > > > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > > > > +} > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +int main(int argc, char *argv[]) > > > > > > > > > > > > > > > +{ > > > > > > > > > > > > > > > + if (argc < 2) { > > > > > > > > > > > > > > > + printUsage(); > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + int fd, ret, arg; > > > > > > > > > > > > > > > + int mask = FAN_OPEN; // default mask > > > > > > > > > > > > > > > + int listening = 0; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + // the -p flag will test for watch_with_perm > > > > > > > > > > > > > > > + // the mask used at mark will contain FAN_OPEN_PERM > > > > > > > > > > > > > > > + // > > > > > > > > > > > > > > > + // the -r flag will test for watching > > > > > > > > > > > > > > > accesses to files for reads > > > > > > > > > > > > > > > + // the mask will contain FAN_ACCESS > > > > > > > > > > > > > > > + while ((arg = getopt(argc, argv, "prl")) != -1) { > > > > > > > > > > > > > > > + switch (arg) { > > > > > > > > > > > > > > > + case 'p': > > > > > > > > > > > > > > > + mask |= FAN_OPEN_PERM; > > > > > > > > > > > > > > > + break; > > > > > > > > > > > > > > > + case 'r': > > > > > > > > > > > > > > > + mask |= FAN_ACCESS; > > > > > > > > > > > > > > > + break; > > > > > > > > > > > > > > > + case 'l': > > > > > > > > > > > > > > > + listening = 1; > > > > > > > > > > > > > > > + break; > > > > > > > > > > > > > > > + default: > > > > > > > > > > > > > > > + printUsage(); > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + // get file descriptor for new fanotify event queue > > > > > > > > > > > > > > > + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); > > > > > > > > > > > > > > > + if (fd < 0) { > > > > > > > > > > > > > > > + perror("fanotify_init:bad file descriptor"); > > > > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + // mark a filesystem object and add mark to event queue > > > > > > > > > > > > > > > + // get notifications on file opens, accesses, and closes > > > > > > > > > > > > > > > + // use current working directory as base dir > > > > > > > > > > > > > > > + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, > > > > > > > > > > > > > > > AT_FDCWD, argv[optind]); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + if (ret < 0) { > > > > > > > > > > > > > > > + perror("test_fanotify:watch denied"); > > > > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + // logic to actually listen for an event if > > > > > > > > > > > > > > > the -l flag is passed > > > > > > > > > > > > > > > + // this is used to test if an app with > > > > > > > > > > > > > > > read-only access can get a read/write > > > > > > > > > > > > > > > + // handle to the watched file > > > > > > > > > > > > > > > + if (listening) { > > > > > > > > > > > > > > > + if (fork() == 0) { // fork a child > > > > > > > > > > > > > > > process to cause an event on the file > > > > > > > > > > > > > > > + FILE *f; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + f = > > > > > > > > > > > > > > > fopen(argv[optind], > > > > > > > > > > > > > > > "r"); // open file > > > > > > > > > > > > > > > for reading > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > fgetc(f); > > > > > > > > > > > > > > > // read char from > > > > > > > > > > > > > > > file > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + fclose(f); > > > > > > > > > > > > > > > + } else { // logic to watch for events > > > > > > > > > > > > > > > and try to access file read/write > > > > > > > > > > > > > > > + struct pollfd fds; > > > > > > > > > > > > > > > + fds.fd = fd; > > > > > > > > > > > > > > > + fds.events = POLLIN; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + while (listening) { > > > > > > > > > > > > > > > + int polled = poll(&fds, 1, 1); > > > > > > > > > > > > > > > + if (polled > 0) { > > > > > > > > > > > > > > > + if (fds.revents & POLLIN) { > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > struct > > > > > > > > > > > > > > > fanotify_event_metadata > > > > > > > > > > > > > > > buff[200]; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + size_t len = read(fd, > > > > > > > > > > > > > > > (void *)&buff, sizeof(buff)); > > > > > > > > > > > > > > > + if (len == -1) { > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > perror("test_fanotify:can't open file"); > > > > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > > > > + } else { > > > > > > > > > > > > > > > + listening = 0; > > > > > > > > > > > > > > > + break; > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + } else if (polled == -1) { > > > > > > > > > > > > > > > + listening = 0; > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + exit(0); > > > > > > > > > > > > > > > +} > > > > > > > > > > > > > > > diff --git a/tests/notify/test_inotify.c > > > > > > > > > > > > > > > b/tests/notify/test_inotify.c > > > > > > > > > > > > > > > new file mode 100644 > > > > > > > > > > > > > > > index 0000000..17c3565 > > > > > > > > > > > > > > > --- /dev/null > > > > > > > > > > > > > > > +++ b/tests/notify/test_inotify.c > > > > > > > > > > > > > > > @@ -0,0 +1,43 @@ > > > > > > > > > > > > > > > +#include <stdio.h> > > > > > > > > > > > > > > > +#include <stdlib.h> > > > > > > > > > > > > > > > +#include <sys/inotify.h> > > > > > > > > > > > > > > > +#include <getopt.h> > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > +int main(int argc, char *argv[]) > > > > > > > > > > > > > > > +{ > > > > > > > > > > > > > > > + if (argc < 2) { > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > fprintf(stderr, > > > > > > > > > > > > > > > "Usage: test_inotify > > > > > > > > > > > > > > > [-r] file_name\n"); > > > > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + int fd, wd, arg; > > > > > > > > > > > > > > > + int mask = IN_MODIFY; > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + while ((arg = getopt(argc, argv, "pr")) != -1) { > > > > > > > > > > > > > > > + switch (arg) { > > > > > > > > > > > > > > > + case 'r': > > > > > > > > > > > > > > > + mask |= IN_ACCESS; > > > > > > > > > > > > > > > + break; > > > > > > > > > > > > > > > + default: > > > > > > > > > > > > > > > + fprintf(stderr, "Usage: > > > > > > > > > > > > > > > test_inotify [-r] file_name\n"); > > > > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + // get new file descriptor for inotify access > > > > > > > > > > > > > > > + fd = inotify_init(); > > > > > > > > > > > > > > > + if (fd < 0) { > > > > > > > > > > > > > > > + perror("inotify_init:bad file descriptor"); > > > > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + // set watch on file and get watch > > > > > > > > > > > > > > > descriptor for accessing events on it > > > > > > > > > > > > > > > + wd = inotify_add_watch(fd, argv[optind], mask); > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + if (wd < 0) { > > > > > > > > > > > > > > > + perror("test_inotify:watch denied"); > > > > > > > > > > > > > > > + exit(1); > > > > > > > > > > > > > > > + } > > > > > > > > > > > > > > > + > > > > > > > > > > > > > > > + exit(0); > > > > > > > > > > > > > > > +} > > > > > > > > > > > > > > > -- > > > > > > > > > > > > > > > 2.21.0 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
On 8/27/19 1:14 PM, Paul Moore wrote: > On Wed, Jul 10, 2019 at 9:40 AM Aaron Goidel <acgoide@tycho.nsa.gov> wrote: >> >> Added a suite to test permissions for setting inotify and fanotify watches >> on filesystem objects. Tests watch, watch_with_perm, and watch_reads permissions. >> >> Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> >> --- >> policy/Makefile | 4 ++ >> policy/test_notify.te | 74 ++++++++++++++++++++++++ >> tests/Makefile | 4 ++ >> tests/notify/Makefile | 5 ++ >> tests/notify/test | 101 +++++++++++++++++++++++++++++++++ >> tests/notify/test_fanotify.c | 105 +++++++++++++++++++++++++++++++++++ >> tests/notify/test_inotify.c | 43 ++++++++++++++ >> 7 files changed, 336 insertions(+) >> create mode 100644 policy/test_notify.te >> create mode 100644 tests/notify/Makefile >> create mode 100755 tests/notify/test >> create mode 100644 tests/notify/test_fanotify.c >> create mode 100644 tests/notify/test_inotify.c > > FYI, I'm still waiting on the new permissions to show up in the > Rawhide policy so I can test this and verify everything is working > correctly with a "released" policy. > > I also had to perform a number of fixes to get 'make check-syntax' to > run cleanly. Anything we could/should do to help this along?
diff --git a/policy/Makefile b/policy/Makefile index 305b572..65f88c5 100644 --- a/policy/Makefile +++ b/policy/Makefile @@ -71,6 +71,10 @@ ifeq ($(shell grep -q corenet_sctp_bind_all_nodes $(POLDEV)/include/kernel/coren TARGETS += test_sctp.te endif +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) +TARGETS+=test_notify.te +endif + ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te, $(TARGETS)) endif diff --git a/policy/test_notify.te b/policy/test_notify.te new file mode 100644 index 0000000..8ba6f1a --- /dev/null +++ b/policy/test_notify.te @@ -0,0 +1,74 @@ +#################################################### +# Policy for testing inoftify and fanotify watches # +#################################################### + +attribute test_notify_domain; + +# Type for the file on which we want to set a watch +type test_notify_file_t; +files_type(test_notify_file_t); + +# Domain for the process which CAN set a non-permission watch +type test_watch_t; +domain_type(test_watch_t); +unconfined_runs_test(test_watch_t); + +typeattribute test_watch_t test_notify_domain; +typeattribute test_watch_t testdomain; + +allow test_notify_domain self:capability sys_admin; + +allow test_watch_t test_notify_file_t:file { read write open watch }; + +# Domain for the process which CAN set a NON-access watch on a file +type test_perm_watch_t; +domain_type(test_perm_watch_t); +unconfined_runs_test(test_perm_watch_t); + +typeattribute test_perm_watch_t test_notify_domain; +typeattribute test_perm_watch_t testdomain; + +allow test_perm_watch_t test_notify_file_t:file { read write open watch watch_with_perm }; + +# Domain which CAN set a NON-perm watch which MAY read accesses +type test_read_watch_t; +domain_type(test_read_watch_t); +unconfined_runs_test(test_read_watch_t); + +typeattribute test_read_watch_t test_notify_domain; +typeattribute test_read_watch_t testdomain; + +allow test_read_watch_t test_notify_file_t:file { read write open watch watch_reads }; + +# Domain which CAN set any watch which CAN read accesses +type test_perm_read_watch_t; +domain_type(test_perm_read_watch_t); +unconfined_runs_test(test_perm_read_watch_t); + +typeattribute test_perm_read_watch_t test_notify_domain; +typeattribute test_perm_read_watch_t testdomain; + +allow test_perm_read_watch_t test_notify_file_t:file { read write open watch watch_with_perm watch_reads }; + +# Domain which CANNOT set any watches +type test_no_watch_t; +domain_type(test_no_watch_t); +unconfined_runs_test(test_no_watch_t); + +typeattribute test_no_watch_t test_notify_domain; +typeattribute test_no_watch_t testdomain; + +allow test_no_watch_t test_notify_file_t:file { read write open }; + +# Domain which has no write access but can watch +type test_rdonly_t; +domain_type(test_rdonly_t); +unconfined_runs_test(test_rdonly_t); + +typeattribute test_rdonly_t test_notify_domain; +typeattribute test_rdonly_t testdomain; + +allow test_rdonly_t test_notify_file_t:file { read open watch }; + +miscfiles_domain_entry_test_files(test_notify_domain); +userdom_sysadm_entry_spec_domtrans_to(test_notify_domain); diff --git a/tests/Makefile b/tests/Makefile index 63aa325..b99c96e 100644 --- a/tests/Makefile +++ b/tests/Makefile @@ -50,6 +50,10 @@ ifeq ($(shell grep "^SELINUX_INFINIBAND_PKEY_TEST=" infiniband_pkey/ibpkey_test. SUBDIRS += infiniband_pkey endif +ifeq ($(shell grep -q all_file_perms.*watch $(POLDEV)/include/support/all_perms.spt && echo true),true) +SUBDIRS+=notify +endif + ifeq ($(DISTRO),RHEL4) SUBDIRS:=$(filter-out bounds dyntrace dyntrans inet_socket mmap nnp_nosuid overlay unix_socket, $(SUBDIRS)) endif diff --git a/tests/notify/Makefile b/tests/notify/Makefile new file mode 100644 index 0000000..78c4b3b --- /dev/null +++ b/tests/notify/Makefile @@ -0,0 +1,5 @@ +TARGETS=test_inotify test_fanotify + +all: $(TARGETS) +clean: + rm -f $(TARGETS) diff --git a/tests/notify/test b/tests/notify/test new file mode 100755 index 0000000..21f03de --- /dev/null +++ b/tests/notify/test @@ -0,0 +1,101 @@ +#!/usr/bin/perl + +use Test; +BEGIN { plan tests => 14 } # number of tests to run + +# help the test script locate itself +$basedir = $0; +$basedir =~ s|(.*)/[^/]*|$1|; + +# Get rid of a testfile from last run if it's there (just in case) +system("rm -f $basedir/watch_me"); + +# Create a new test file +system("touch $basedir/watch_me"); +system("chcon -t test_notify_file_t $basedir/watch_me"); + +## TESTS + +## TEST BASIC WATCH PERMISSION +# Should be able to set inotify watch +$exit_val = + system("runcon -t test_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); +ok( $exit_val, 0 ); + +# Should be able to set non-permissions based fanotify watch +$exit_val = system( + "runcon -t test_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); +ok( $exit_val, 0 ); + +# Should NOT be able to set permission based fanotify watch +$exit_val = system( + "runcon -t test_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1"); +ok($exit_val); # this should fail + +# Should NOT be able to set read based fanotify watch +$exit_val = system( + "runcon -t test_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1"); +ok($exit_val); # this should fail + +# Should NOT be able to set read based inotify watch +$exit_val = system( + "runcon -t test_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1"); +ok($exit_val); # this should fail + +## TEST PERM WATCH +# Should be able to set permission based fanotify watch +$exit_val = system( +"runcon -t test_perm_watch_t $basedir/test_fanotify -p $basedir/watch_me 2>&1" +); +ok( $exit_val, 0 ); + +# Should NOT be able to set watch of accesses +$exit_val = system( +"runcon -t test_perm_watch_t $basedir/test_fanotify -r $basedir/watch_me 2>&1" +); +ok($exit_val); # this should fail + +## TEST READ NO PERM WATCH PERMSISSIONS +# Should NOT be able to set read and perm watch +$exit_val = system( +"runcon -t test_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" +); +ok($exit_val); # should fail + +# Should be able to set read inotify watch +$exit_val = system( +"runcon -t test_read_watch_t $basedir/test_inotify -r $basedir/watch_me 2>&1" +); +ok( $exit_val, 0 ); + +## TEST READ WITH PERM WATCH PERMSISSIONS +# Should be able to set read and perm watch +$exit_val = system( +"runcon -t test_perm_read_watch_t $basedir/test_fanotify -p -r $basedir/watch_me 2>&1" +); +ok( $exit_val, 0 ); + +## TEST NO WATCH PERMSISSIONS +# Should NOT be able to set inotify watch +$exit_val = system( + "runcon -t test_no_watch_t $basedir/test_inotify $basedir/watch_me 2>&1"); +ok($exit_val); # this should fail + +# Should NOT be able to set any fanotify watch +$exit_val = system( + "runcon -t test_no_watch_t $basedir/test_fanotify $basedir/watch_me 2>&1"); +ok($exit_val); # this should fail + +## TEST READ ONLY +# Should NOT be able to get read-write descriptor +$exit_val = system( + "runcon -t test_rdonly_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); +ok($exit_val); # this should fail + +# Should be able to get read-write descriptor +$exit_val = system( + "runcon -t test_watch_t $basedir/test_fanotify -l $basedir/watch_me 2>&1"); +ok( $exit_val, 0 ); + +# Clean up test file +system("rm -f $basedir/watch_me"); diff --git a/tests/notify/test_fanotify.c b/tests/notify/test_fanotify.c new file mode 100644 index 0000000..fff773f --- /dev/null +++ b/tests/notify/test_fanotify.c @@ -0,0 +1,105 @@ +#define _GNU_SOURCE 1 + +#include <stdio.h> +#include <stdlib.h> + +#include <getopt.h> + +#include <fcntl.h> +#include <poll.h> +#include <sys/fanotify.h> +#include <unistd.h> + +void printUsage() +{ + fprintf(stderr, "Usage: test_fanotify [-p] [-r] [-l] file_name\n"); + exit(1); +} + +int main(int argc, char *argv[]) +{ + if (argc < 2) { + printUsage(); + } + + int fd, ret, arg; + int mask = FAN_OPEN; // default mask + int listening = 0; + + // the -p flag will test for watch_with_perm + // the mask used at mark will contain FAN_OPEN_PERM + // + // the -r flag will test for watching accesses to files for reads + // the mask will contain FAN_ACCESS + while ((arg = getopt(argc, argv, "prl")) != -1) { + switch (arg) { + case 'p': + mask |= FAN_OPEN_PERM; + break; + case 'r': + mask |= FAN_ACCESS; + break; + case 'l': + listening = 1; + break; + default: + printUsage(); + } + } + + // get file descriptor for new fanotify event queue + fd = fanotify_init(FAN_CLASS_CONTENT, O_RDWR); + if (fd < 0) { + perror("fanotify_init:bad file descriptor"); + exit(1); + } + + // mark a filesystem object and add mark to event queue + // get notifications on file opens, accesses, and closes + // use current working directory as base dir + ret = fanotify_mark(fd, FAN_MARK_ADD, mask, AT_FDCWD, argv[optind]); + + if (ret < 0) { + perror("test_fanotify:watch denied"); + exit(1); + } + + // logic to actually listen for an event if the -l flag is passed + // this is used to test if an app with read-only access can get a read/write + // handle to the watched file + if (listening) { + if (fork() == 0) { // fork a child process to cause an event on the file + FILE *f; + + f = fopen(argv[optind], "r"); // open file for reading + fgetc(f); // read char from file + + fclose(f); + } else { // logic to watch for events and try to access file read/write + struct pollfd fds; + fds.fd = fd; + fds.events = POLLIN; + + while (listening) { + int polled = poll(&fds, 1, 1); + if (polled > 0) { + if (fds.revents & POLLIN) { + struct fanotify_event_metadata buff[200]; + + size_t len = read(fd, (void *)&buff, sizeof(buff)); + if (len == -1) { + perror("test_fanotify:can't open file"); + exit(1); + } else { + listening = 0; + break; + } + } + } else if (polled == -1) { + listening = 0; + } + } + } + } + exit(0); +} diff --git a/tests/notify/test_inotify.c b/tests/notify/test_inotify.c new file mode 100644 index 0000000..17c3565 --- /dev/null +++ b/tests/notify/test_inotify.c @@ -0,0 +1,43 @@ +#include <stdio.h> +#include <stdlib.h> +#include <sys/inotify.h> +#include <getopt.h> + +int main(int argc, char *argv[]) +{ + if (argc < 2) { + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); + exit(1); + } + + int fd, wd, arg; + int mask = IN_MODIFY; + + while ((arg = getopt(argc, argv, "pr")) != -1) { + switch (arg) { + case 'r': + mask |= IN_ACCESS; + break; + default: + fprintf(stderr, "Usage: test_inotify [-r] file_name\n"); + exit(1); + } + } + + // get new file descriptor for inotify access + fd = inotify_init(); + if (fd < 0) { + perror("inotify_init:bad file descriptor"); + exit(1); + } + + // set watch on file and get watch descriptor for accessing events on it + wd = inotify_add_watch(fd, argv[optind], mask); + + if (wd < 0) { + perror("test_inotify:watch denied"); + exit(1); + } + + exit(0); +}
Added a suite to test permissions for setting inotify and fanotify watches on filesystem objects. Tests watch, watch_with_perm, and watch_reads permissions. Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> --- policy/Makefile | 4 ++ policy/test_notify.te | 74 ++++++++++++++++++++++++ tests/Makefile | 4 ++ tests/notify/Makefile | 5 ++ tests/notify/test | 101 +++++++++++++++++++++++++++++++++ tests/notify/test_fanotify.c | 105 +++++++++++++++++++++++++++++++++++ tests/notify/test_inotify.c | 43 ++++++++++++++ 7 files changed, 336 insertions(+) create mode 100644 policy/test_notify.te create mode 100644 tests/notify/Makefile create mode 100755 tests/notify/test create mode 100644 tests/notify/test_fanotify.c create mode 100644 tests/notify/test_inotify.c