| Message ID | 20170728121040.631-2-otubo@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Jul 28, 2017 at 02:10:35PM +0200, Eduardo Otubo wrote: > This patch changes the default behavior of the seccomp filter from > whitelist to blacklist. By default now all system calls are allowed and > a small black list of definitely forbidden ones was created. > > Signed-off-by: Eduardo Otubo <otubo@redhat.com> > --- > qemu-seccomp.c | 256 +++++++-------------------------------------------------- > vl.c | 5 +- > 2 files changed, 32 insertions(+), 229 deletions(-) > > diff --git a/qemu-seccomp.c b/qemu-seccomp.c > index df75d9c471..f8877b07b5 100644 > --- a/qemu-seccomp.c > +++ b/qemu-seccomp.c > @@ -31,229 +31,29 @@ struct QemuSeccompSyscall { > uint8_t priority; > }; > > -static const struct QemuSeccompSyscall seccomp_whitelist[] = { > - { SCMP_SYS(timer_settime), 255 }, > - { SCMP_SYS(timer_gettime), 254 }, > - { SCMP_SYS(futex), 253 }, > - { SCMP_SYS(select), 252 }, > - { SCMP_SYS(recvfrom), 251 }, > - { SCMP_SYS(sendto), 250 }, > - { SCMP_SYS(socketcall), 250 }, > - { SCMP_SYS(read), 249 }, > - { SCMP_SYS(io_submit), 249 }, > - { SCMP_SYS(brk), 248 }, > - { SCMP_SYS(clone), 247 }, > - { SCMP_SYS(mmap), 247 }, > - { SCMP_SYS(mprotect), 246 }, > - { SCMP_SYS(execve), 245 }, > - { SCMP_SYS(open), 245 }, > - { SCMP_SYS(ioctl), 245 }, > - { SCMP_SYS(socket), 245 }, > - { SCMP_SYS(setsockopt), 245 }, > - { SCMP_SYS(recvmsg), 245 }, > - { SCMP_SYS(sendmsg), 245 }, > - { SCMP_SYS(accept), 245 }, > - { SCMP_SYS(connect), 245 }, > - { SCMP_SYS(socketpair), 245 }, > - { SCMP_SYS(bind), 245 }, > - { SCMP_SYS(listen), 245 }, > - { SCMP_SYS(semget), 245 }, > - { SCMP_SYS(ipc), 245 }, > - { SCMP_SYS(gettimeofday), 245 }, > - { SCMP_SYS(readlink), 245 }, > - { SCMP_SYS(access), 245 }, > - { SCMP_SYS(prctl), 245 }, > - { SCMP_SYS(signalfd), 245 }, > - { SCMP_SYS(getrlimit), 245 }, > - { SCMP_SYS(getrusage), 245 }, > - { SCMP_SYS(set_tid_address), 245 }, > - { SCMP_SYS(statfs), 245 }, > - { SCMP_SYS(unlink), 245 }, > - { SCMP_SYS(wait4), 245 }, > - { SCMP_SYS(fcntl64), 245 }, > - { SCMP_SYS(fstat64), 245 }, > - { SCMP_SYS(stat64), 245 }, > - { SCMP_SYS(getgid32), 245 }, > - { SCMP_SYS(getegid32), 245 }, > - { SCMP_SYS(getuid32), 245 }, > - { SCMP_SYS(geteuid32), 245 }, > - { SCMP_SYS(sigreturn), 245 }, > - { SCMP_SYS(_newselect), 245 }, > - { SCMP_SYS(_llseek), 245 }, > - { SCMP_SYS(mmap2), 245 }, > - { SCMP_SYS(sigprocmask), 245 }, > - { SCMP_SYS(sched_getparam), 245 }, > - { SCMP_SYS(sched_getscheduler), 245 }, > - { SCMP_SYS(fstat), 245 }, > - { SCMP_SYS(clock_getres), 245 }, > - { SCMP_SYS(sched_get_priority_min), 245 }, > - { SCMP_SYS(sched_get_priority_max), 245 }, > - { SCMP_SYS(stat), 245 }, > - { SCMP_SYS(uname), 245 }, > - { SCMP_SYS(eventfd2), 245 }, > - { SCMP_SYS(io_getevents), 245 }, > - { SCMP_SYS(dup), 245 }, > - { SCMP_SYS(dup2), 245 }, > - { SCMP_SYS(dup3), 245 }, > - { SCMP_SYS(gettid), 245 }, > - { SCMP_SYS(getgid), 245 }, > - { SCMP_SYS(getegid), 245 }, > - { SCMP_SYS(getuid), 245 }, > - { SCMP_SYS(geteuid), 245 }, > - { SCMP_SYS(timer_create), 245 }, > - { SCMP_SYS(times), 245 }, > - { SCMP_SYS(exit), 245 }, > - { SCMP_SYS(clock_gettime), 245 }, > - { SCMP_SYS(time), 245 }, > - { SCMP_SYS(restart_syscall), 245 }, > - { SCMP_SYS(pwrite64), 245 }, > - { SCMP_SYS(nanosleep), 245 }, > - { SCMP_SYS(chown), 245 }, > - { SCMP_SYS(openat), 245 }, > - { SCMP_SYS(getdents), 245 }, > - { SCMP_SYS(timer_delete), 245 }, > - { SCMP_SYS(exit_group), 245 }, > - { SCMP_SYS(rt_sigreturn), 245 }, > - { SCMP_SYS(sync), 245 }, > - { SCMP_SYS(pread64), 245 }, > - { SCMP_SYS(madvise), 245 }, > - { SCMP_SYS(set_robust_list), 245 }, > - { SCMP_SYS(lseek), 245 }, > - { SCMP_SYS(pselect6), 245 }, > - { SCMP_SYS(fork), 245 }, > - { SCMP_SYS(rt_sigprocmask), 245 }, > - { SCMP_SYS(write), 244 }, > - { SCMP_SYS(fcntl), 243 }, > - { SCMP_SYS(tgkill), 242 }, > - { SCMP_SYS(kill), 242 }, > - { SCMP_SYS(rt_sigaction), 242 }, > - { SCMP_SYS(pipe2), 242 }, > - { SCMP_SYS(munmap), 242 }, > - { SCMP_SYS(mremap), 242 }, > - { SCMP_SYS(fdatasync), 242 }, > - { SCMP_SYS(close), 242 }, > - { SCMP_SYS(rt_sigpending), 242 }, > - { SCMP_SYS(rt_sigtimedwait), 242 }, > - { SCMP_SYS(readv), 242 }, > - { SCMP_SYS(writev), 242 }, > - { SCMP_SYS(preadv), 242 }, > - { SCMP_SYS(pwritev), 242 }, > - { SCMP_SYS(setrlimit), 242 }, > - { SCMP_SYS(ftruncate), 242 }, > - { SCMP_SYS(lstat), 242 }, > - { SCMP_SYS(pipe), 242 }, > - { SCMP_SYS(umask), 242 }, > - { SCMP_SYS(chdir), 242 }, > - { SCMP_SYS(setitimer), 242 }, > - { SCMP_SYS(setsid), 242 }, > - { SCMP_SYS(poll), 242 }, > - { SCMP_SYS(epoll_create), 242 }, > - { SCMP_SYS(epoll_ctl), 242 }, > - { SCMP_SYS(epoll_wait), 242 }, > - { SCMP_SYS(waitpid), 242 }, > - { SCMP_SYS(getsockname), 242 }, > - { SCMP_SYS(getpeername), 242 }, > - { SCMP_SYS(accept4), 242 }, > - { SCMP_SYS(timerfd_settime), 242 }, > - { SCMP_SYS(newfstatat), 241 }, > - { SCMP_SYS(shutdown), 241 }, > - { SCMP_SYS(getsockopt), 241 }, > - { SCMP_SYS(semop), 241 }, > - { SCMP_SYS(semtimedop), 241 }, > - { SCMP_SYS(epoll_ctl_old), 241 }, > - { SCMP_SYS(epoll_wait_old), 241 }, > - { SCMP_SYS(epoll_pwait), 241 }, > - { SCMP_SYS(epoll_create1), 241 }, > - { SCMP_SYS(ppoll), 241 }, > - { SCMP_SYS(creat), 241 }, > - { SCMP_SYS(link), 241 }, > - { SCMP_SYS(getpid), 241 }, > - { SCMP_SYS(getppid), 241 }, > - { SCMP_SYS(getpgrp), 241 }, > - { SCMP_SYS(getpgid), 241 }, > - { SCMP_SYS(getsid), 241 }, > - { SCMP_SYS(getdents64), 241 }, > - { SCMP_SYS(getresuid), 241 }, > - { SCMP_SYS(getresgid), 241 }, > - { SCMP_SYS(getgroups), 241 }, > - { SCMP_SYS(getresuid32), 241 }, > - { SCMP_SYS(getresgid32), 241 }, > - { SCMP_SYS(getgroups32), 241 }, > - { SCMP_SYS(signal), 241 }, > - { SCMP_SYS(sigaction), 241 }, > - { SCMP_SYS(sigsuspend), 241 }, > - { SCMP_SYS(sigpending), 241 }, > - { SCMP_SYS(truncate64), 241 }, > - { SCMP_SYS(ftruncate64), 241 }, > - { SCMP_SYS(fchown32), 241 }, > - { SCMP_SYS(chown32), 241 }, > - { SCMP_SYS(lchown32), 241 }, > - { SCMP_SYS(statfs64), 241 }, > - { SCMP_SYS(fstatfs64), 241 }, > - { SCMP_SYS(fstatat64), 241 }, > - { SCMP_SYS(lstat64), 241 }, > - { SCMP_SYS(sendfile64), 241 }, > - { SCMP_SYS(ugetrlimit), 241 }, > - { SCMP_SYS(alarm), 241 }, > - { SCMP_SYS(rt_sigsuspend), 241 }, > - { SCMP_SYS(rt_sigqueueinfo), 241 }, > - { SCMP_SYS(rt_tgsigqueueinfo), 241 }, > - { SCMP_SYS(sigaltstack), 241 }, > - { SCMP_SYS(signalfd4), 241 }, > - { SCMP_SYS(truncate), 241 }, > - { SCMP_SYS(fchown), 241 }, > - { SCMP_SYS(lchown), 241 }, > - { SCMP_SYS(fchownat), 241 }, > - { SCMP_SYS(fstatfs), 241 }, > - { SCMP_SYS(getitimer), 241 }, > - { SCMP_SYS(syncfs), 241 }, > - { SCMP_SYS(fsync), 241 }, > - { SCMP_SYS(fchdir), 241 }, > - { SCMP_SYS(msync), 241 }, > - { SCMP_SYS(sched_setparam), 241 }, > - { SCMP_SYS(sched_setscheduler), 241 }, > - { SCMP_SYS(sched_yield), 241 }, > - { SCMP_SYS(sched_rr_get_interval), 241 }, > - { SCMP_SYS(sched_setaffinity), 241 }, > - { SCMP_SYS(sched_getaffinity), 241 }, > - { SCMP_SYS(readahead), 241 }, > - { SCMP_SYS(timer_getoverrun), 241 }, > - { SCMP_SYS(unlinkat), 241 }, > - { SCMP_SYS(readlinkat), 241 }, > - { SCMP_SYS(faccessat), 241 }, > - { SCMP_SYS(get_robust_list), 241 }, > - { SCMP_SYS(splice), 241 }, > - { SCMP_SYS(vmsplice), 241 }, > - { SCMP_SYS(getcpu), 241 }, > - { SCMP_SYS(sendmmsg), 241 }, > - { SCMP_SYS(recvmmsg), 241 }, > - { SCMP_SYS(prlimit64), 241 }, > - { SCMP_SYS(waitid), 241 }, > - { SCMP_SYS(io_cancel), 241 }, > - { SCMP_SYS(io_setup), 241 }, > - { SCMP_SYS(io_destroy), 241 }, > - { SCMP_SYS(arch_prctl), 240 }, > - { SCMP_SYS(mkdir), 240 }, > - { SCMP_SYS(fchmod), 240 }, > - { SCMP_SYS(shmget), 240 }, > - { SCMP_SYS(shmat), 240 }, > - { SCMP_SYS(shmdt), 240 }, > - { SCMP_SYS(timerfd_create), 240 }, > - { SCMP_SYS(shmctl), 240 }, > - { SCMP_SYS(mlockall), 240 }, > - { SCMP_SYS(mlock), 240 }, > - { SCMP_SYS(munlock), 240 }, > - { SCMP_SYS(semctl), 240 }, > - { SCMP_SYS(fallocate), 240 }, > - { SCMP_SYS(fadvise64), 240 }, > - { SCMP_SYS(inotify_init1), 240 }, > - { SCMP_SYS(inotify_add_watch), 240 }, > - { SCMP_SYS(mbind), 240 }, > - { SCMP_SYS(memfd_create), 240 }, > -#ifdef HAVE_CACHEFLUSH > - { SCMP_SYS(cacheflush), 240 }, > -#endif > - { SCMP_SYS(sysinfo), 240 }, > +static const struct QemuSeccompSyscall blacklist[] = { > + { SCMP_SYS(reboot), 255 }, > + { SCMP_SYS(swapon), 255 }, > + { SCMP_SYS(swapoff), 255 }, > + { SCMP_SYS(syslog), 255 }, > + { SCMP_SYS(mount), 255 }, > + { SCMP_SYS(umount), 255 }, > + { SCMP_SYS(kexec_load), 255 }, > + { SCMP_SYS(afs_syscall), 255 }, > + { SCMP_SYS(break), 255 }, > + { SCMP_SYS(ftime), 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(security), 255 }, > + { SCMP_SYS(stty), 255 }, > + { SCMP_SYS(tuxcall), 255 }, > + { SCMP_SYS(ulimit), 255 }, > + { SCMP_SYS(vserver), 255 }, > }; > > int seccomp_start(void) > @@ -262,19 +62,19 @@ int seccomp_start(void) > unsigned int i = 0; > scmp_filter_ctx ctx; > > - ctx = seccomp_init(SCMP_ACT_KILL); > + ctx = seccomp_init(SCMP_ACT_ALLOW); > if (ctx == NULL) { > rc = -1; > goto seccomp_return; > } > > - for (i = 0; i < ARRAY_SIZE(seccomp_whitelist); i++) { > - rc = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, seccomp_whitelist[i].num, 0); > + for (i = 0; i < ARRAY_SIZE(blacklist); i++) { > + rc = seccomp_rule_add(ctx, SCMP_ACT_KILL, blacklist[i].num, 0); > if (rc < 0) { > goto seccomp_return; > } > - rc = seccomp_syscall_priority(ctx, seccomp_whitelist[i].num, > - seccomp_whitelist[i].priority); > + rc = seccomp_syscall_priority(ctx, blacklist[i].num, > + blacklist[i].priority); > if (rc < 0) { > goto seccomp_return; > } > diff --git a/vl.c b/vl.c > index fb6b2efafa..15b98800e9 100644 > --- a/vl.c > +++ b/vl.c > @@ -1030,13 +1030,16 @@ static int bt_parse(const char *opt) > > 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) { > error_report("failed to install seccomp syscall filter " > "in the kernel"); > return -1; > + } else { > + error_report("warning: -sandbox on has been converted to blacklist " > + "approach. Refer to the manual for new sandbox " > + "options in order to increase security."); This is just noise that will pollute everyone's logs. This kind of thing can just be put in the QEMU release notes. If you remove this, then Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Regards, Daniel
On 28.07.2017 14:10, Eduardo Otubo wrote: > This patch changes the default behavior of the seccomp filter from > whitelist to blacklist. By default now all system calls are allowed and > a small black list of definitely forbidden ones was created. > > Signed-off-by: Eduardo Otubo <otubo@redhat.com> > --- > qemu-seccomp.c | 256 +++++++-------------------------------------------------- > vl.c | 5 +- > 2 files changed, 32 insertions(+), 229 deletions(-) > > diff --git a/qemu-seccomp.c b/qemu-seccomp.c > index df75d9c471..f8877b07b5 100644 > --- a/qemu-seccomp.c > +++ b/qemu-seccomp.c > @@ -31,229 +31,29 @@ struct QemuSeccompSyscall { > uint8_t priority; > }; [...] > +static const struct QemuSeccompSyscall blacklist[] = { > + { SCMP_SYS(reboot), 255 }, > + { SCMP_SYS(swapon), 255 }, > + { SCMP_SYS(swapoff), 255 }, > + { SCMP_SYS(syslog), 255 }, > + { SCMP_SYS(mount), 255 }, > + { SCMP_SYS(umount), 255 }, > + { SCMP_SYS(kexec_load), 255 }, > + { SCMP_SYS(afs_syscall), 255 }, > + { SCMP_SYS(break), 255 }, > + { SCMP_SYS(ftime), 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(security), 255 }, > + { SCMP_SYS(stty), 255 }, > + { SCMP_SYS(tuxcall), 255 }, > + { SCMP_SYS(ulimit), 255 }, > + { SCMP_SYS(vserver), 255 }, > }; Does it makes sense to still keep the priority field? Everything is now marked with the value 255 and I currently fail to see the point of priorities when using blacklisting ... so maybe just get rid of it? Thomas
On Thu, Aug 03, 2017 at 06:54:15PM +0200, Thomas Huth wrote: > On 28.07.2017 14:10, Eduardo Otubo wrote: > > This patch changes the default behavior of the seccomp filter from > > whitelist to blacklist. By default now all system calls are allowed and > > a small black list of definitely forbidden ones was created. > > > > Signed-off-by: Eduardo Otubo <otubo@redhat.com> > > --- > > qemu-seccomp.c | 256 +++++++-------------------------------------------------- > > vl.c | 5 +- > > 2 files changed, 32 insertions(+), 229 deletions(-) > > > > diff --git a/qemu-seccomp.c b/qemu-seccomp.c > > index df75d9c471..f8877b07b5 100644 > > --- a/qemu-seccomp.c > > +++ b/qemu-seccomp.c > > @@ -31,229 +31,29 @@ struct QemuSeccompSyscall { > > uint8_t priority; > > }; > [...] > > +static const struct QemuSeccompSyscall blacklist[] = { > > + { SCMP_SYS(reboot), 255 }, > > + { SCMP_SYS(swapon), 255 }, > > + { SCMP_SYS(swapoff), 255 }, > > + { SCMP_SYS(syslog), 255 }, > > + { SCMP_SYS(mount), 255 }, > > + { SCMP_SYS(umount), 255 }, > > + { SCMP_SYS(kexec_load), 255 }, > > + { SCMP_SYS(afs_syscall), 255 }, > > + { SCMP_SYS(break), 255 }, > > + { SCMP_SYS(ftime), 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(security), 255 }, > > + { SCMP_SYS(stty), 255 }, > > + { SCMP_SYS(tuxcall), 255 }, > > + { SCMP_SYS(ulimit), 255 }, > > + { SCMP_SYS(vserver), 255 }, > > }; > > Does it makes sense to still keep the priority field? Everything is now > marked with the value 255 and I currently fail to see the point of > priorities when using blacklisting ... so maybe just get rid of it? I think that's a fair point here. Don't see much of a point on such a small number of syscalls. I just need to double check the libseccomp docs if I can build the list without any priority information, but I'm pretty sure I've seen this before.
On Fri, Aug 11, 2017 at 11:51:12AM +0200, Eduardo Otubo wrote: > On Thu, Aug 03, 2017 at 06:54:15PM +0200, Thomas Huth wrote: > > On 28.07.2017 14:10, Eduardo Otubo wrote: > > > This patch changes the default behavior of the seccomp filter from > > > whitelist to blacklist. By default now all system calls are allowed and > > > a small black list of definitely forbidden ones was created. > > > > > > Signed-off-by: Eduardo Otubo <otubo@redhat.com> > > > --- > > > qemu-seccomp.c | 256 +++++++-------------------------------------------------- > > > vl.c | 5 +- > > > 2 files changed, 32 insertions(+), 229 deletions(-) > > > > > > diff --git a/qemu-seccomp.c b/qemu-seccomp.c > > > index df75d9c471..f8877b07b5 100644 > > > --- a/qemu-seccomp.c > > > +++ b/qemu-seccomp.c > > > @@ -31,229 +31,29 @@ struct QemuSeccompSyscall { > > > uint8_t priority; > > > }; > > [...] > > > +static const struct QemuSeccompSyscall blacklist[] = { > > > + { SCMP_SYS(reboot), 255 }, > > > + { SCMP_SYS(swapon), 255 }, > > > + { SCMP_SYS(swapoff), 255 }, > > > + { SCMP_SYS(syslog), 255 }, > > > + { SCMP_SYS(mount), 255 }, > > > + { SCMP_SYS(umount), 255 }, > > > + { SCMP_SYS(kexec_load), 255 }, > > > + { SCMP_SYS(afs_syscall), 255 }, > > > + { SCMP_SYS(break), 255 }, > > > + { SCMP_SYS(ftime), 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(security), 255 }, > > > + { SCMP_SYS(stty), 255 }, > > > + { SCMP_SYS(tuxcall), 255 }, > > > + { SCMP_SYS(ulimit), 255 }, > > > + { SCMP_SYS(vserver), 255 }, > > > }; > > > > Does it makes sense to still keep the priority field? Everything is now > > marked with the value 255 and I currently fail to see the point of > > priorities when using blacklisting ... so maybe just get rid of it? > > I think that's a fair point here. Don't see much of a point on such a > small number of syscalls. I just need to double check the libseccomp > docs if I can build the list without any priority information, but I'm > pretty sure I've seen this before. Just always pass 255 to libseccomp apis directly. Its merely redundant to store the value 255 in this QEMU specific struct. Regards, Daniel
diff --git a/qemu-seccomp.c b/qemu-seccomp.c index df75d9c471..f8877b07b5 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -31,229 +31,29 @@ struct QemuSeccompSyscall { uint8_t priority; }; -static const struct QemuSeccompSyscall seccomp_whitelist[] = { - { SCMP_SYS(timer_settime), 255 }, - { SCMP_SYS(timer_gettime), 254 }, - { SCMP_SYS(futex), 253 }, - { SCMP_SYS(select), 252 }, - { SCMP_SYS(recvfrom), 251 }, - { SCMP_SYS(sendto), 250 }, - { SCMP_SYS(socketcall), 250 }, - { SCMP_SYS(read), 249 }, - { SCMP_SYS(io_submit), 249 }, - { SCMP_SYS(brk), 248 }, - { SCMP_SYS(clone), 247 }, - { SCMP_SYS(mmap), 247 }, - { SCMP_SYS(mprotect), 246 }, - { SCMP_SYS(execve), 245 }, - { SCMP_SYS(open), 245 }, - { SCMP_SYS(ioctl), 245 }, - { SCMP_SYS(socket), 245 }, - { SCMP_SYS(setsockopt), 245 }, - { SCMP_SYS(recvmsg), 245 }, - { SCMP_SYS(sendmsg), 245 }, - { SCMP_SYS(accept), 245 }, - { SCMP_SYS(connect), 245 }, - { SCMP_SYS(socketpair), 245 }, - { SCMP_SYS(bind), 245 }, - { SCMP_SYS(listen), 245 }, - { SCMP_SYS(semget), 245 }, - { SCMP_SYS(ipc), 245 }, - { SCMP_SYS(gettimeofday), 245 }, - { SCMP_SYS(readlink), 245 }, - { SCMP_SYS(access), 245 }, - { SCMP_SYS(prctl), 245 }, - { SCMP_SYS(signalfd), 245 }, - { SCMP_SYS(getrlimit), 245 }, - { SCMP_SYS(getrusage), 245 }, - { SCMP_SYS(set_tid_address), 245 }, - { SCMP_SYS(statfs), 245 }, - { SCMP_SYS(unlink), 245 }, - { SCMP_SYS(wait4), 245 }, - { SCMP_SYS(fcntl64), 245 }, - { SCMP_SYS(fstat64), 245 }, - { SCMP_SYS(stat64), 245 }, - { SCMP_SYS(getgid32), 245 }, - { SCMP_SYS(getegid32), 245 }, - { SCMP_SYS(getuid32), 245 }, - { SCMP_SYS(geteuid32), 245 }, - { SCMP_SYS(sigreturn), 245 }, - { SCMP_SYS(_newselect), 245 }, - { SCMP_SYS(_llseek), 245 }, - { SCMP_SYS(mmap2), 245 }, - { SCMP_SYS(sigprocmask), 245 }, - { SCMP_SYS(sched_getparam), 245 }, - { SCMP_SYS(sched_getscheduler), 245 }, - { SCMP_SYS(fstat), 245 }, - { SCMP_SYS(clock_getres), 245 }, - { SCMP_SYS(sched_get_priority_min), 245 }, - { SCMP_SYS(sched_get_priority_max), 245 }, - { SCMP_SYS(stat), 245 }, - { SCMP_SYS(uname), 245 }, - { SCMP_SYS(eventfd2), 245 }, - { SCMP_SYS(io_getevents), 245 }, - { SCMP_SYS(dup), 245 }, - { SCMP_SYS(dup2), 245 }, - { SCMP_SYS(dup3), 245 }, - { SCMP_SYS(gettid), 245 }, - { SCMP_SYS(getgid), 245 }, - { SCMP_SYS(getegid), 245 }, - { SCMP_SYS(getuid), 245 }, - { SCMP_SYS(geteuid), 245 }, - { SCMP_SYS(timer_create), 245 }, - { SCMP_SYS(times), 245 }, - { SCMP_SYS(exit), 245 }, - { SCMP_SYS(clock_gettime), 245 }, - { SCMP_SYS(time), 245 }, - { SCMP_SYS(restart_syscall), 245 }, - { SCMP_SYS(pwrite64), 245 }, - { SCMP_SYS(nanosleep), 245 }, - { SCMP_SYS(chown), 245 }, - { SCMP_SYS(openat), 245 }, - { SCMP_SYS(getdents), 245 }, - { SCMP_SYS(timer_delete), 245 }, - { SCMP_SYS(exit_group), 245 }, - { SCMP_SYS(rt_sigreturn), 245 }, - { SCMP_SYS(sync), 245 }, - { SCMP_SYS(pread64), 245 }, - { SCMP_SYS(madvise), 245 }, - { SCMP_SYS(set_robust_list), 245 }, - { SCMP_SYS(lseek), 245 }, - { SCMP_SYS(pselect6), 245 }, - { SCMP_SYS(fork), 245 }, - { SCMP_SYS(rt_sigprocmask), 245 }, - { SCMP_SYS(write), 244 }, - { SCMP_SYS(fcntl), 243 }, - { SCMP_SYS(tgkill), 242 }, - { SCMP_SYS(kill), 242 }, - { SCMP_SYS(rt_sigaction), 242 }, - { SCMP_SYS(pipe2), 242 }, - { SCMP_SYS(munmap), 242 }, - { SCMP_SYS(mremap), 242 }, - { SCMP_SYS(fdatasync), 242 }, - { SCMP_SYS(close), 242 }, - { SCMP_SYS(rt_sigpending), 242 }, - { SCMP_SYS(rt_sigtimedwait), 242 }, - { SCMP_SYS(readv), 242 }, - { SCMP_SYS(writev), 242 }, - { SCMP_SYS(preadv), 242 }, - { SCMP_SYS(pwritev), 242 }, - { SCMP_SYS(setrlimit), 242 }, - { SCMP_SYS(ftruncate), 242 }, - { SCMP_SYS(lstat), 242 }, - { SCMP_SYS(pipe), 242 }, - { SCMP_SYS(umask), 242 }, - { SCMP_SYS(chdir), 242 }, - { SCMP_SYS(setitimer), 242 }, - { SCMP_SYS(setsid), 242 }, - { SCMP_SYS(poll), 242 }, - { SCMP_SYS(epoll_create), 242 }, - { SCMP_SYS(epoll_ctl), 242 }, - { SCMP_SYS(epoll_wait), 242 }, - { SCMP_SYS(waitpid), 242 }, - { SCMP_SYS(getsockname), 242 }, - { SCMP_SYS(getpeername), 242 }, - { SCMP_SYS(accept4), 242 }, - { SCMP_SYS(timerfd_settime), 242 }, - { SCMP_SYS(newfstatat), 241 }, - { SCMP_SYS(shutdown), 241 }, - { SCMP_SYS(getsockopt), 241 }, - { SCMP_SYS(semop), 241 }, - { SCMP_SYS(semtimedop), 241 }, - { SCMP_SYS(epoll_ctl_old), 241 }, - { SCMP_SYS(epoll_wait_old), 241 }, - { SCMP_SYS(epoll_pwait), 241 }, - { SCMP_SYS(epoll_create1), 241 }, - { SCMP_SYS(ppoll), 241 }, - { SCMP_SYS(creat), 241 }, - { SCMP_SYS(link), 241 }, - { SCMP_SYS(getpid), 241 }, - { SCMP_SYS(getppid), 241 }, - { SCMP_SYS(getpgrp), 241 }, - { SCMP_SYS(getpgid), 241 }, - { SCMP_SYS(getsid), 241 }, - { SCMP_SYS(getdents64), 241 }, - { SCMP_SYS(getresuid), 241 }, - { SCMP_SYS(getresgid), 241 }, - { SCMP_SYS(getgroups), 241 }, - { SCMP_SYS(getresuid32), 241 }, - { SCMP_SYS(getresgid32), 241 }, - { SCMP_SYS(getgroups32), 241 }, - { SCMP_SYS(signal), 241 }, - { SCMP_SYS(sigaction), 241 }, - { SCMP_SYS(sigsuspend), 241 }, - { SCMP_SYS(sigpending), 241 }, - { SCMP_SYS(truncate64), 241 }, - { SCMP_SYS(ftruncate64), 241 }, - { SCMP_SYS(fchown32), 241 }, - { SCMP_SYS(chown32), 241 }, - { SCMP_SYS(lchown32), 241 }, - { SCMP_SYS(statfs64), 241 }, - { SCMP_SYS(fstatfs64), 241 }, - { SCMP_SYS(fstatat64), 241 }, - { SCMP_SYS(lstat64), 241 }, - { SCMP_SYS(sendfile64), 241 }, - { SCMP_SYS(ugetrlimit), 241 }, - { SCMP_SYS(alarm), 241 }, - { SCMP_SYS(rt_sigsuspend), 241 }, - { SCMP_SYS(rt_sigqueueinfo), 241 }, - { SCMP_SYS(rt_tgsigqueueinfo), 241 }, - { SCMP_SYS(sigaltstack), 241 }, - { SCMP_SYS(signalfd4), 241 }, - { SCMP_SYS(truncate), 241 }, - { SCMP_SYS(fchown), 241 }, - { SCMP_SYS(lchown), 241 }, - { SCMP_SYS(fchownat), 241 }, - { SCMP_SYS(fstatfs), 241 }, - { SCMP_SYS(getitimer), 241 }, - { SCMP_SYS(syncfs), 241 }, - { SCMP_SYS(fsync), 241 }, - { SCMP_SYS(fchdir), 241 }, - { SCMP_SYS(msync), 241 }, - { SCMP_SYS(sched_setparam), 241 }, - { SCMP_SYS(sched_setscheduler), 241 }, - { SCMP_SYS(sched_yield), 241 }, - { SCMP_SYS(sched_rr_get_interval), 241 }, - { SCMP_SYS(sched_setaffinity), 241 }, - { SCMP_SYS(sched_getaffinity), 241 }, - { SCMP_SYS(readahead), 241 }, - { SCMP_SYS(timer_getoverrun), 241 }, - { SCMP_SYS(unlinkat), 241 }, - { SCMP_SYS(readlinkat), 241 }, - { SCMP_SYS(faccessat), 241 }, - { SCMP_SYS(get_robust_list), 241 }, - { SCMP_SYS(splice), 241 }, - { SCMP_SYS(vmsplice), 241 }, - { SCMP_SYS(getcpu), 241 }, - { SCMP_SYS(sendmmsg), 241 }, - { SCMP_SYS(recvmmsg), 241 }, - { SCMP_SYS(prlimit64), 241 }, - { SCMP_SYS(waitid), 241 }, - { SCMP_SYS(io_cancel), 241 }, - { SCMP_SYS(io_setup), 241 }, - { SCMP_SYS(io_destroy), 241 }, - { SCMP_SYS(arch_prctl), 240 }, - { SCMP_SYS(mkdir), 240 }, - { SCMP_SYS(fchmod), 240 }, - { SCMP_SYS(shmget), 240 }, - { SCMP_SYS(shmat), 240 }, - { SCMP_SYS(shmdt), 240 }, - { SCMP_SYS(timerfd_create), 240 }, - { SCMP_SYS(shmctl), 240 }, - { SCMP_SYS(mlockall), 240 }, - { SCMP_SYS(mlock), 240 }, - { SCMP_SYS(munlock), 240 }, - { SCMP_SYS(semctl), 240 }, - { SCMP_SYS(fallocate), 240 }, - { SCMP_SYS(fadvise64), 240 }, - { SCMP_SYS(inotify_init1), 240 }, - { SCMP_SYS(inotify_add_watch), 240 }, - { SCMP_SYS(mbind), 240 }, - { SCMP_SYS(memfd_create), 240 }, -#ifdef HAVE_CACHEFLUSH - { SCMP_SYS(cacheflush), 240 }, -#endif - { SCMP_SYS(sysinfo), 240 }, +static const struct QemuSeccompSyscall blacklist[] = { + { SCMP_SYS(reboot), 255 }, + { SCMP_SYS(swapon), 255 }, + { SCMP_SYS(swapoff), 255 }, + { SCMP_SYS(syslog), 255 }, + { SCMP_SYS(mount), 255 }, + { SCMP_SYS(umount), 255 }, + { SCMP_SYS(kexec_load), 255 }, + { SCMP_SYS(afs_syscall), 255 }, + { SCMP_SYS(break), 255 }, + { SCMP_SYS(ftime), 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(security), 255 }, + { SCMP_SYS(stty), 255 }, + { SCMP_SYS(tuxcall), 255 }, + { SCMP_SYS(ulimit), 255 }, + { SCMP_SYS(vserver), 255 }, }; int seccomp_start(void) @@ -262,19 +62,19 @@ int seccomp_start(void) unsigned int i = 0; scmp_filter_ctx ctx; - ctx = seccomp_init(SCMP_ACT_KILL); + ctx = seccomp_init(SCMP_ACT_ALLOW); if (ctx == NULL) { rc = -1; goto seccomp_return; } - for (i = 0; i < ARRAY_SIZE(seccomp_whitelist); i++) { - rc = seccomp_rule_add(ctx, SCMP_ACT_ALLOW, seccomp_whitelist[i].num, 0); + for (i = 0; i < ARRAY_SIZE(blacklist); i++) { + rc = seccomp_rule_add(ctx, SCMP_ACT_KILL, blacklist[i].num, 0); if (rc < 0) { goto seccomp_return; } - rc = seccomp_syscall_priority(ctx, seccomp_whitelist[i].num, - seccomp_whitelist[i].priority); + rc = seccomp_syscall_priority(ctx, blacklist[i].num, + blacklist[i].priority); if (rc < 0) { goto seccomp_return; } diff --git a/vl.c b/vl.c index fb6b2efafa..15b98800e9 100644 --- a/vl.c +++ b/vl.c @@ -1030,13 +1030,16 @@ static int bt_parse(const char *opt) 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) { error_report("failed to install seccomp syscall filter " "in the kernel"); return -1; + } else { + error_report("warning: -sandbox on has been converted to blacklist " + "approach. Refer to the manual for new sandbox " + "options in order to increase security."); } #else error_report("seccomp support is disabled");
This patch changes the default behavior of the seccomp filter from whitelist to blacklist. By default now all system calls are allowed and a small black list of definitely forbidden ones was created. Signed-off-by: Eduardo Otubo <otubo@redhat.com> --- qemu-seccomp.c | 256 +++++++-------------------------------------------------- vl.c | 5 +- 2 files changed, 32 insertions(+), 229 deletions(-)