| Message ID | 20170314113209.12025-3-eduardo.otubo@profitbricks.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 14/03/2017 12:32, Eduardo Otubo wrote: > +static const struct QemuSeccompSyscall obsolete[] = { > + { SCMP_SYS(readdir), 255 }, > + { SCMP_SYS(_sysctl), 255 }, > + { SCMP_SYS(afs_syscall), 255 }, > + { SCMP_SYS(bdflush), 255 }, > + { SCMP_SYS(break), 255 }, > + { SCMP_SYS(create_module), 255 }, > + { SCMP_SYS(ftime), 255 }, > + { SCMP_SYS(get_kernel_syms), 255 }, > + { SCMP_SYS(getpmsg), 255 }, > + { SCMP_SYS(gtty), 255 }, > + { SCMP_SYS(lock), 255 }, > + { SCMP_SYS(mpx), 255 }, > + { SCMP_SYS(prof), 255 }, > + { SCMP_SYS(profil), 255 }, > + { SCMP_SYS(putpmsg), 255 }, > + { SCMP_SYS(query_module), 255 }, > + { SCMP_SYS(security), 255 }, > + { SCMP_SYS(sgetmask), 255 }, > + { SCMP_SYS(ssetmask), 255 }, > + { SCMP_SYS(stty), 255 }, > + { SCMP_SYS(sysfs), 255 }, > + { SCMP_SYS(tuxcall), 255 }, > + { SCMP_SYS(ulimit), 255 }, > + { SCMP_SYS(uselib), 255 }, > + { SCMP_SYS(ustat), 255 }, > + { SCMP_SYS(vserver), 255 }, > +}; Some of these are already blacklisted in patch 1. Paolo
On 14.03.2017 12:32, Eduardo Otubo wrote: > This patch introduces the argument [,obsolete=allow] to the `-sandbox on' > option. It allows Qemu to run safely on old system that still relies on > old system calls. > > Signed-off-by: Eduardo Otubo <eduardo.otubo@profitbricks.com> > --- > include/sysemu/seccomp.h | 4 +++- > qemu-options.hx | 9 +++++++-- > qemu-seccomp.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++- > vl.c | 16 +++++++++++++++- > 4 files changed, 71 insertions(+), 5 deletions(-) > > diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h > index cfc06008cb..7a7bde246b 100644 > --- a/include/sysemu/seccomp.h > +++ b/include/sysemu/seccomp.h > @@ -15,7 +15,9 @@ > #ifndef QEMU_SECCOMP_H > #define QEMU_SECCOMP_H > > +#define OBSOLETE 0x0001 > + > #include <seccomp.h> > > -int seccomp_start(void); > +int seccomp_start(uint8_t seccomp_opts); > #endif > diff --git a/qemu-options.hx b/qemu-options.hx > index 8dd8ee34a6..1403d0c85f 100644 > --- a/qemu-options.hx > +++ b/qemu-options.hx > @@ -3732,13 +3732,18 @@ Old param mode (ARM only). > ETEXI > > DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ > - "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n", > + "-sandbox on[,obsolete=allow] Enable seccomp mode 2 system call filter (default 'off').\n" \ > + " obsolete: Allow obsolete system calls", > QEMU_ARCH_ALL) > STEXI > -@item -sandbox @var{arg} > +@item -sandbox @var{arg}[,obsolete=@var{string}] > @findex -sandbox > Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will > disable it. The default is 'off'. > +@table @option > +@item obsolete=@var{string} > +Enable Obsolete system calls > +@end table > ETEXI > > DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, > diff --git a/qemu-seccomp.c b/qemu-seccomp.c > index f8877b07b5..5ef36890da 100644 > --- a/qemu-seccomp.c > +++ b/qemu-seccomp.c > @@ -31,6 +31,35 @@ struct QemuSeccompSyscall { > uint8_t priority; > }; > > +static const struct QemuSeccompSyscall obsolete[] = { > + { SCMP_SYS(readdir), 255 }, > + { SCMP_SYS(_sysctl), 255 }, > + { SCMP_SYS(afs_syscall), 255 }, > + { SCMP_SYS(bdflush), 255 }, > + { SCMP_SYS(break), 255 }, > + { SCMP_SYS(create_module), 255 }, > + { SCMP_SYS(ftime), 255 }, > + { SCMP_SYS(get_kernel_syms), 255 }, > + { SCMP_SYS(getpmsg), 255 }, > + { SCMP_SYS(gtty), 255 }, > + { SCMP_SYS(lock), 255 }, > + { SCMP_SYS(mpx), 255 }, > + { SCMP_SYS(prof), 255 }, > + { SCMP_SYS(profil), 255 }, > + { SCMP_SYS(putpmsg), 255 }, > + { SCMP_SYS(query_module), 255 }, > + { SCMP_SYS(security), 255 }, > + { SCMP_SYS(sgetmask), 255 }, > + { SCMP_SYS(ssetmask), 255 }, > + { SCMP_SYS(stty), 255 }, > + { SCMP_SYS(sysfs), 255 }, > + { SCMP_SYS(tuxcall), 255 }, > + { SCMP_SYS(ulimit), 255 }, > + { SCMP_SYS(uselib), 255 }, > + { SCMP_SYS(ustat), 255 }, > + { SCMP_SYS(vserver), 255 }, > +}; > + > static const struct QemuSeccompSyscall blacklist[] = { > { SCMP_SYS(reboot), 255 }, > { SCMP_SYS(swapon), 255 }, > @@ -56,7 +85,20 @@ static const struct QemuSeccompSyscall blacklist[] = { > { SCMP_SYS(vserver), 255 }, > }; > > -int seccomp_start(void) > +static int is_obsolete(int syscall) > +{ > + unsigned int i = 0; > + > + for (i = 0; i < ARRAY_SIZE(obsolete); i++) { > + if (syscall == obsolete[i].num) { > + return 1; > + } > + } > + > + return 0; > +} > + > +int seccomp_start(uint8_t seccomp_opts) > { > int rc = 0; > unsigned int i = 0; > @@ -69,6 +111,9 @@ int seccomp_start(void) > } > > for (i = 0; i < ARRAY_SIZE(blacklist); i++) { > + if ((seccomp_opts & OBSOLETE) && is_obsolete(blacklist[i].num)) { > + continue; > + } > rc = seccomp_rule_add(ctx, SCMP_ACT_KILL, blacklist[i].num, 0); > if (rc < 0) { > goto seccomp_return; > diff --git a/vl.c b/vl.c > index 1a95500ac7..7b08b3383b 100644 > --- a/vl.c > +++ b/vl.c > @@ -269,6 +269,10 @@ static QemuOptsList qemu_sandbox_opts = { > .name = "enable", > .type = QEMU_OPT_BOOL, > }, > + { > + .name = "obsolete", > + .type = QEMU_OPT_STRING, > + }, Since this is basically a boolean switch, could you maybe rather use "QEMU_OPT_BOOL" here, too (and also in the following patches)? I think it is also easier for the users to memorize "obsolete=on" instead of yet-another-parameter-syntax like "obsolete=allow". Thomas
On Tue, Mar 14, 2017 at 01=01=11PM +0100, Thomas Huth wrote: > On 14.03.2017 12:32, Eduardo Otubo wrote: > > This patch introduces the argument [,obsolete=allow] to the `-sandbox on' > > option. It allows Qemu to run safely on old system that still relies on > > old system calls. > > > > Signed-off-by: Eduardo Otubo <eduardo.otubo@profitbricks.com> > > --- > > include/sysemu/seccomp.h | 4 +++- > > qemu-options.hx | 9 +++++++-- > > qemu-seccomp.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++- > > vl.c | 16 +++++++++++++++- > > 4 files changed, 71 insertions(+), 5 deletions(-) > > > > diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h > > index cfc06008cb..7a7bde246b 100644 > > --- a/include/sysemu/seccomp.h > > +++ b/include/sysemu/seccomp.h > > @@ -15,7 +15,9 @@ > > #ifndef QEMU_SECCOMP_H > > #define QEMU_SECCOMP_H > > > > +#define OBSOLETE 0x0001 > > + > > #include <seccomp.h> > > > > -int seccomp_start(void); > > +int seccomp_start(uint8_t seccomp_opts); > > #endif > > diff --git a/qemu-options.hx b/qemu-options.hx > > index 8dd8ee34a6..1403d0c85f 100644 > > --- a/qemu-options.hx > > +++ b/qemu-options.hx > > @@ -3732,13 +3732,18 @@ Old param mode (ARM only). > > ETEXI > > > > DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ > > - "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n", > > + "-sandbox on[,obsolete=allow] Enable seccomp mode 2 system call filter (default 'off').\n" \ > > + " obsolete: Allow obsolete system calls", > > QEMU_ARCH_ALL) > > STEXI > > -@item -sandbox @var{arg} > > +@item -sandbox @var{arg}[,obsolete=@var{string}] > > @findex -sandbox > > Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will > > disable it. The default is 'off'. > > +@table @option > > +@item obsolete=@var{string} > > +Enable Obsolete system calls > > +@end table > > ETEXI > > > > DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, > > diff --git a/qemu-seccomp.c b/qemu-seccomp.c > > index f8877b07b5..5ef36890da 100644 > > --- a/qemu-seccomp.c > > +++ b/qemu-seccomp.c > > @@ -31,6 +31,35 @@ struct QemuSeccompSyscall { > > uint8_t priority; > > }; > > > > +static const struct QemuSeccompSyscall obsolete[] = { > > + { SCMP_SYS(readdir), 255 }, > > + { SCMP_SYS(_sysctl), 255 }, > > + { SCMP_SYS(afs_syscall), 255 }, > > + { SCMP_SYS(bdflush), 255 }, > > + { SCMP_SYS(break), 255 }, > > + { SCMP_SYS(create_module), 255 }, > > + { SCMP_SYS(ftime), 255 }, > > + { SCMP_SYS(get_kernel_syms), 255 }, > > + { SCMP_SYS(getpmsg), 255 }, > > + { SCMP_SYS(gtty), 255 }, > > + { SCMP_SYS(lock), 255 }, > > + { SCMP_SYS(mpx), 255 }, > > + { SCMP_SYS(prof), 255 }, > > + { SCMP_SYS(profil), 255 }, > > + { SCMP_SYS(putpmsg), 255 }, > > + { SCMP_SYS(query_module), 255 }, > > + { SCMP_SYS(security), 255 }, > > + { SCMP_SYS(sgetmask), 255 }, > > + { SCMP_SYS(ssetmask), 255 }, > > + { SCMP_SYS(stty), 255 }, > > + { SCMP_SYS(sysfs), 255 }, > > + { SCMP_SYS(tuxcall), 255 }, > > + { SCMP_SYS(ulimit), 255 }, > > + { SCMP_SYS(uselib), 255 }, > > + { SCMP_SYS(ustat), 255 }, > > + { SCMP_SYS(vserver), 255 }, > > +}; > > + > > static const struct QemuSeccompSyscall blacklist[] = { > > { SCMP_SYS(reboot), 255 }, > > { SCMP_SYS(swapon), 255 }, > > @@ -56,7 +85,20 @@ static const struct QemuSeccompSyscall blacklist[] = { > > { SCMP_SYS(vserver), 255 }, > > }; > > > > -int seccomp_start(void) > > +static int is_obsolete(int syscall) > > +{ > > + unsigned int i = 0; > > + > > + for (i = 0; i < ARRAY_SIZE(obsolete); i++) { > > + if (syscall == obsolete[i].num) { > > + return 1; > > + } > > + } > > + > > + return 0; > > +} > > + > > +int seccomp_start(uint8_t seccomp_opts) > > { > > int rc = 0; > > unsigned int i = 0; > > @@ -69,6 +111,9 @@ int seccomp_start(void) > > } > > > > for (i = 0; i < ARRAY_SIZE(blacklist); i++) { > > + if ((seccomp_opts & OBSOLETE) && is_obsolete(blacklist[i].num)) { > > + continue; > > + } > > rc = seccomp_rule_add(ctx, SCMP_ACT_KILL, blacklist[i].num, 0); > > if (rc < 0) { > > goto seccomp_return; > > diff --git a/vl.c b/vl.c > > index 1a95500ac7..7b08b3383b 100644 > > --- a/vl.c > > +++ b/vl.c > > @@ -269,6 +269,10 @@ static QemuOptsList qemu_sandbox_opts = { > > .name = "enable", > > .type = QEMU_OPT_BOOL, > > }, > > + { > > + .name = "obsolete", > > + .type = QEMU_OPT_STRING, > > + }, > > Since this is basically a boolean switch, could you maybe rather use > "QEMU_OPT_BOOL" here, too (and also in the following patches)? I think > it is also easier for the users to memorize "obsolete=on" instead of > yet-another-parameter-syntax like "obsolete=allow". > Yes, that's definitely in my mind. I just wanted to make the first draft the same way Daniel designed and evolve from there.
diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h index cfc06008cb..7a7bde246b 100644 --- a/include/sysemu/seccomp.h +++ b/include/sysemu/seccomp.h @@ -15,7 +15,9 @@ #ifndef QEMU_SECCOMP_H #define QEMU_SECCOMP_H +#define OBSOLETE 0x0001 + #include <seccomp.h> -int seccomp_start(void); +int seccomp_start(uint8_t seccomp_opts); #endif diff --git a/qemu-options.hx b/qemu-options.hx index 8dd8ee34a6..1403d0c85f 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3732,13 +3732,18 @@ Old param mode (ARM only). ETEXI DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ - "-sandbox <arg> Enable seccomp mode 2 system call filter (default 'off').\n", + "-sandbox on[,obsolete=allow] Enable seccomp mode 2 system call filter (default 'off').\n" \ + " obsolete: Allow obsolete system calls", QEMU_ARCH_ALL) STEXI -@item -sandbox @var{arg} +@item -sandbox @var{arg}[,obsolete=@var{string}] @findex -sandbox Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will disable it. The default is 'off'. +@table @option +@item obsolete=@var{string} +Enable Obsolete system calls +@end table ETEXI DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, diff --git a/qemu-seccomp.c b/qemu-seccomp.c index f8877b07b5..5ef36890da 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -31,6 +31,35 @@ struct QemuSeccompSyscall { uint8_t priority; }; +static const struct QemuSeccompSyscall obsolete[] = { + { SCMP_SYS(readdir), 255 }, + { SCMP_SYS(_sysctl), 255 }, + { SCMP_SYS(afs_syscall), 255 }, + { SCMP_SYS(bdflush), 255 }, + { SCMP_SYS(break), 255 }, + { SCMP_SYS(create_module), 255 }, + { SCMP_SYS(ftime), 255 }, + { SCMP_SYS(get_kernel_syms), 255 }, + { SCMP_SYS(getpmsg), 255 }, + { SCMP_SYS(gtty), 255 }, + { SCMP_SYS(lock), 255 }, + { SCMP_SYS(mpx), 255 }, + { SCMP_SYS(prof), 255 }, + { SCMP_SYS(profil), 255 }, + { SCMP_SYS(putpmsg), 255 }, + { SCMP_SYS(query_module), 255 }, + { SCMP_SYS(security), 255 }, + { SCMP_SYS(sgetmask), 255 }, + { SCMP_SYS(ssetmask), 255 }, + { SCMP_SYS(stty), 255 }, + { SCMP_SYS(sysfs), 255 }, + { SCMP_SYS(tuxcall), 255 }, + { SCMP_SYS(ulimit), 255 }, + { SCMP_SYS(uselib), 255 }, + { SCMP_SYS(ustat), 255 }, + { SCMP_SYS(vserver), 255 }, +}; + static const struct QemuSeccompSyscall blacklist[] = { { SCMP_SYS(reboot), 255 }, { SCMP_SYS(swapon), 255 }, @@ -56,7 +85,20 @@ static const struct QemuSeccompSyscall blacklist[] = { { SCMP_SYS(vserver), 255 }, }; -int seccomp_start(void) +static int is_obsolete(int syscall) +{ + unsigned int i = 0; + + for (i = 0; i < ARRAY_SIZE(obsolete); i++) { + if (syscall == obsolete[i].num) { + return 1; + } + } + + return 0; +} + +int seccomp_start(uint8_t seccomp_opts) { int rc = 0; unsigned int i = 0; @@ -69,6 +111,9 @@ int seccomp_start(void) } for (i = 0; i < ARRAY_SIZE(blacklist); i++) { + if ((seccomp_opts & OBSOLETE) && is_obsolete(blacklist[i].num)) { + continue; + } rc = seccomp_rule_add(ctx, SCMP_ACT_KILL, blacklist[i].num, 0); if (rc < 0) { goto seccomp_return; diff --git a/vl.c b/vl.c index 1a95500ac7..7b08b3383b 100644 --- a/vl.c +++ b/vl.c @@ -269,6 +269,10 @@ static QemuOptsList qemu_sandbox_opts = { .name = "enable", .type = QEMU_OPT_BOOL, }, + { + .name = "obsolete", + .type = QEMU_OPT_STRING, + }, { /* end of list */ } }, }; @@ -1031,7 +1035,17 @@ static int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp) /* FIXME: change this to true for 1.3 */ if (qemu_opt_get_bool(opts, "enable", false)) { #ifdef CONFIG_SECCOMP - if (seccomp_start() < 0) { + uint8_t seccomp_opts = 0x0000; + const char * value = NULL; + + value = qemu_opt_get(opts,"obsolete"); + if (value) { + if (strcmp(value, "allow") == 0) { + seccomp_opts |= OBSOLETE; + } + } + + if (seccomp_start(seccomp_opts) < 0) { error_report("failed to install seccomp syscall filter " "in the kernel"); return -1;
This patch introduces the argument [,obsolete=allow] to the `-sandbox on' option. It allows Qemu to run safely on old system that still relies on old system calls. Signed-off-by: Eduardo Otubo <eduardo.otubo@profitbricks.com> --- include/sysemu/seccomp.h | 4 +++- qemu-options.hx | 9 +++++++-- qemu-seccomp.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++- vl.c | 16 +++++++++++++++- 4 files changed, 71 insertions(+), 5 deletions(-)