* [Qemu-devel] [PATCH 1/6] seccomp: changing from whitelist to blacklist
2017-07-14 11:36 [Qemu-devel] [PATCH 0/6] seccomp: feature refactoring Eduardo Otubo
@ 2017-07-14 11:36 ` Eduardo Otubo
0 siblings, 0 replies; 8+ messages in thread
From: Eduardo Otubo @ 2017-07-14 11:36 UTC (permalink / raw)
To: qemu-devel; +Cc: Eduardo Otubo
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 | 7 +-
2 files changed, 33 insertions(+), 230 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 8efd48bf9f..838ad3b11a 100644
--- a/vl.c
+++ b/vl.c
@@ -1030,14 +1030,17 @@ 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 manual for other options to higher
+ security option.");
+ }
#else
error_report("seccomp support is disabled");
return -1;
--
2.13.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH v3 0/6] seccomp: feature refactoring
@ 2017-07-21 12:52 Eduardo Otubo
2017-07-21 12:52 ` [Qemu-devel] [PATCH 1/6] seccomp: changing from whitelist to blacklist Eduardo Otubo
` (5 more replies)
0 siblings, 6 replies; 8+ messages in thread
From: Eduardo Otubo @ 2017-07-21 12:52 UTC (permalink / raw)
To: qemu-devel
v3:
* Style problems fixed
v2:
* The semantics of the options "allow/deny" instead of booleans "on/off" remains.
* Added option 'children' to elevateprivileges
* Added documentation to docs/
v1:
* First version based on the discussion
https://lists.gnu.org/archive/html/qemu-devel/2017-02/msg03348.html
Eduardo Otubo (6):
seccomp: changing from whitelist to blacklist
seccomp: add obsolete argument to command line
seccomp: add elevateprivileges argument to command line
seccomp: add spawn argument to command line
seccomp: add resourcecontrol argument to command line
seccomp: adding documentation to new seccomp model
docs/seccomp.txt | 31 ++++
include/sysemu/seccomp.h | 7 +-
qemu-options.hx | 19 ++-
qemu-seccomp.c | 364 ++++++++++++++++++-----------------------------
vl.c | 61 +++++++-
5 files changed, 248 insertions(+), 234 deletions(-)
create mode 100644 docs/seccomp.txt
--
2.13.3
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH 1/6] seccomp: changing from whitelist to blacklist
2017-07-21 12:52 [Qemu-devel] [PATCH v3 0/6] seccomp: feature refactoring Eduardo Otubo
@ 2017-07-21 12:52 ` Eduardo Otubo
2017-07-21 12:52 ` [Qemu-devel] [PATCH 2/6] seccomp: add obsolete argument to command line Eduardo Otubo
` (4 subsequent siblings)
5 siblings, 0 replies; 8+ messages in thread
From: Eduardo Otubo @ 2017-07-21 12:52 UTC (permalink / raw)
To: qemu-devel
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.");
}
#else
error_report("seccomp support is disabled");
--
2.13.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH 2/6] seccomp: add obsolete argument to command line
2017-07-21 12:52 [Qemu-devel] [PATCH v3 0/6] seccomp: feature refactoring Eduardo Otubo
2017-07-21 12:52 ` [Qemu-devel] [PATCH 1/6] seccomp: changing from whitelist to blacklist Eduardo Otubo
@ 2017-07-21 12:52 ` Eduardo Otubo
2017-07-21 12:52 ` [Qemu-devel] [PATCH 3/6] seccomp: add elevateprivileges " Eduardo Otubo
` (3 subsequent siblings)
5 siblings, 0 replies; 8+ messages in thread
From: Eduardo Otubo @ 2017-07-21 12:52 UTC (permalink / raw)
To: qemu-devel
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 <otubo@redhat.com>
---
include/sysemu/seccomp.h | 4 +++-
qemu-options.hx | 9 +++++++--
qemu-seccomp.c | 32 +++++++++++++++++++++++++++++++-
vl.c | 16 +++++++++++++++-
4 files changed, 56 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 746b5fa75d..54e492f36a 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4004,13 +4004,18 @@ 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\n",
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..c6a8b28260 100644
--- a/qemu-seccomp.c
+++ b/qemu-seccomp.c
@@ -31,6 +31,20 @@ struct QemuSeccompSyscall {
uint8_t priority;
};
+static const struct QemuSeccompSyscall obsolete[] = {
+ { SCMP_SYS(readdir), 255 },
+ { SCMP_SYS(_sysctl), 255 },
+ { SCMP_SYS(bdflush), 255 },
+ { SCMP_SYS(create_module), 255 },
+ { SCMP_SYS(get_kernel_syms), 255 },
+ { SCMP_SYS(query_module), 255 },
+ { SCMP_SYS(sgetmask), 255 },
+ { SCMP_SYS(ssetmask), 255 },
+ { SCMP_SYS(sysfs), 255 },
+ { SCMP_SYS(uselib), 255 },
+ { SCMP_SYS(ustat), 255 },
+};
+
static const struct QemuSeccompSyscall blacklist[] = {
{ SCMP_SYS(reboot), 255 },
{ SCMP_SYS(swapon), 255 },
@@ -56,7 +70,20 @@ 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 +96,9 @@ 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 15b98800e9..cbe09c94af 100644
--- a/vl.c
+++ b/vl.c
@@ -271,6 +271,10 @@ static QemuOptsList qemu_sandbox_opts = {
.name = "enable",
.type = QEMU_OPT_BOOL,
},
+ {
+ .name = "obsolete",
+ .type = QEMU_OPT_STRING,
+ },
{ /* end of list */ }
},
};
@@ -1032,7 +1036,17 @@ static int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp)
{
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;
--
2.13.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH 3/6] seccomp: add elevateprivileges argument to command line
2017-07-21 12:52 [Qemu-devel] [PATCH v3 0/6] seccomp: feature refactoring Eduardo Otubo
2017-07-21 12:52 ` [Qemu-devel] [PATCH 1/6] seccomp: changing from whitelist to blacklist Eduardo Otubo
2017-07-21 12:52 ` [Qemu-devel] [PATCH 2/6] seccomp: add obsolete argument to command line Eduardo Otubo
@ 2017-07-21 12:52 ` Eduardo Otubo
2017-07-21 12:52 ` [Qemu-devel] [PATCH 4/6] seccomp: add spawn " Eduardo Otubo
` (2 subsequent siblings)
5 siblings, 0 replies; 8+ messages in thread
From: Eduardo Otubo @ 2017-07-21 12:52 UTC (permalink / raw)
To: qemu-devel
This patch introduces the new argument
[,elevateprivileges=allow|deny|children] to the `-sandbox on'. It allows
or denies Qemu process to elevate its privileges by blacklisting all
set*uid|gid system calls. The 'children' option will let forks and
execves run unprivileged.
Signed-off-by: Eduardo Otubo <otubo@redhat.com>
---
include/sysemu/seccomp.h | 1 +
qemu-options.hx | 9 ++++++---
qemu-seccomp.c | 29 +++++++++++++++++++++++++++++
vl.c | 19 +++++++++++++++++++
4 files changed, 55 insertions(+), 3 deletions(-)
diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h
index 7a7bde246b..e6e78d85ce 100644
--- a/include/sysemu/seccomp.h
+++ b/include/sysemu/seccomp.h
@@ -16,6 +16,7 @@
#define QEMU_SECCOMP_H
#define OBSOLETE 0x0001
+#define PRIVILEGED 0x0010
#include <seccomp.h>
diff --git a/qemu-options.hx b/qemu-options.hx
index 54e492f36a..34d33a812e 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4004,17 +4004,20 @@ Old param mode (ARM only).
ETEXI
DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
- "-sandbox on[,obsolete=allow] Enable seccomp mode 2 system call filter (default 'off').\n" \
- " obsolete: Allow obsolete system calls\n",
+ "-sandbox on[,obsolete=allow][,elevateprivileges=allow|deny|children] Enable seccomp mode 2 system call filter (default 'off').\n" \
+ " obsolete: Allow obsolete system calls\n"
+ " elevateprivileges: allows or denies Qemu process to elevate its privileges by blacklisting all set*uid|gid system calls. 'children' will deny set*uid|gid system calls for main Qemu process but will allow forks and execves to run unprivileged\n",
QEMU_ARCH_ALL)
STEXI
-@item -sandbox @var{arg}[,obsolete=@var{string}]
+@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@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
+@item elevateprivileges=@var{string}
+Disable set*uid|gid systema calls
@end table
ETEXI
diff --git a/qemu-seccomp.c b/qemu-seccomp.c
index c6a8b28260..6caa513edd 100644
--- a/qemu-seccomp.c
+++ b/qemu-seccomp.c
@@ -31,6 +31,19 @@ struct QemuSeccompSyscall {
uint8_t priority;
};
+static const struct QemuSeccompSyscall privileged_syscalls[] = {
+ { SCMP_SYS(setuid), 255 },
+ { SCMP_SYS(setgid), 255 },
+ { SCMP_SYS(setpgid), 255 },
+ { SCMP_SYS(setsid), 255 },
+ { SCMP_SYS(setreuid), 255 },
+ { SCMP_SYS(setregid), 255 },
+ { SCMP_SYS(setresuid), 255 },
+ { SCMP_SYS(setresgid), 255 },
+ { SCMP_SYS(setfsuid), 255 },
+ { SCMP_SYS(setfsgid), 255 },
+};
+
static const struct QemuSeccompSyscall obsolete[] = {
{ SCMP_SYS(readdir), 255 },
{ SCMP_SYS(_sysctl), 255 },
@@ -110,6 +123,22 @@ int seccomp_start(uint8_t seccomp_opts)
}
}
+ if (seccomp_opts & PRIVILEGED) {
+ for (i = 0; i < ARRAY_SIZE(privileged_syscalls); i++) {
+ rc = seccomp_rule_add(ctx, SCMP_ACT_KILL,
+ privileged_syscalls[i].num, 0);
+ if (rc < 0) {
+ goto seccomp_return;
+ }
+ rc = seccomp_syscall_priority(ctx, privileged_syscalls[i].num,
+ privileged_syscalls[i].priority);
+ if (rc < 0) {
+ goto seccomp_return;
+ }
+ }
+ }
+
+
rc = seccomp_load(ctx);
seccomp_return:
diff --git a/vl.c b/vl.c
index cbe09c94af..f2b2f10b7b 100644
--- a/vl.c
+++ b/vl.c
@@ -29,6 +29,7 @@
#ifdef CONFIG_SECCOMP
#include "sysemu/seccomp.h"
+#include "sys/prctl.h"
#endif
#if defined(CONFIG_VDE)
@@ -275,6 +276,10 @@ static QemuOptsList qemu_sandbox_opts = {
.name = "obsolete",
.type = QEMU_OPT_STRING,
},
+ {
+ .name = "elevateprivileges",
+ .type = QEMU_OPT_STRING,
+ },
{ /* end of list */ }
},
};
@@ -1046,6 +1051,20 @@ static int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp)
}
}
+ value = qemu_opt_get(opts, "elevateprivileges");
+ if (value) {
+ if (strcmp(value, "deny") == 0) {
+ seccomp_opts |= PRIVILEGED;
+ }
+ if (strcmp(value, "children") == 0) {
+ seccomp_opts |= PRIVILEGED;
+
+ /* calling prctl directly because we're
+ * not sure if host has CAP_SYS_ADMIN set*/
+ prctl(PR_SET_NO_NEW_PRIVS, 1);
+ }
+ }
+
if (seccomp_start(seccomp_opts) < 0) {
error_report("failed to install seccomp syscall filter "
"in the kernel");
--
2.13.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH 4/6] seccomp: add spawn argument to command line
2017-07-21 12:52 [Qemu-devel] [PATCH v3 0/6] seccomp: feature refactoring Eduardo Otubo
` (2 preceding siblings ...)
2017-07-21 12:52 ` [Qemu-devel] [PATCH 3/6] seccomp: add elevateprivileges " Eduardo Otubo
@ 2017-07-21 12:52 ` Eduardo Otubo
2017-07-21 12:52 ` [Qemu-devel] [PATCH 5/6] seccomp: add resourcecontrol " Eduardo Otubo
2017-07-21 12:52 ` [Qemu-devel] [PATCH 6/6] seccomp: adding documentation to new seccomp model Eduardo Otubo
5 siblings, 0 replies; 8+ messages in thread
From: Eduardo Otubo @ 2017-07-21 12:52 UTC (permalink / raw)
To: qemu-devel
This patch adds [,spawn=deny] argument to `-sandbox on' option. It
blacklists fork and execve system calls, avoiding Qemu to spawn new
threads or processes.
Signed-off-by: Eduardo Otubo <otubo@redhat.com>
---
include/sysemu/seccomp.h | 1 +
qemu-options.hx | 9 ++++++---
qemu-seccomp.c | 19 +++++++++++++++++++
vl.c | 11 +++++++++++
4 files changed, 37 insertions(+), 3 deletions(-)
diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h
index e6e78d85ce..f1614d6514 100644
--- a/include/sysemu/seccomp.h
+++ b/include/sysemu/seccomp.h
@@ -17,6 +17,7 @@
#define OBSOLETE 0x0001
#define PRIVILEGED 0x0010
+#define SPAWN 0x0100
#include <seccomp.h>
diff --git a/qemu-options.hx b/qemu-options.hx
index 34d33a812e..3d612f0fd1 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4004,12 +4004,13 @@ Old param mode (ARM only).
ETEXI
DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
- "-sandbox on[,obsolete=allow][,elevateprivileges=allow|deny|children] Enable seccomp mode 2 system call filter (default 'off').\n" \
+ "-sandbox on[,obsolete=allow][,elevateprivileges=allow|deny|children][,spawn=deny] Enable seccomp mode 2 system call filter (default 'off').\n" \
" obsolete: Allow obsolete system calls\n"
- " elevateprivileges: allows or denies Qemu process to elevate its privileges by blacklisting all set*uid|gid system calls. 'children' will deny set*uid|gid system calls for main Qemu process but will allow forks and execves to run unprivileged\n",
+ " elevateprivileges: allows or denies Qemu process to elevate its privileges by blacklisting all set*uid|gid system calls. 'children' will deny set*uid|gid system calls for main Qemu process but will allow forks and execves to run unprivileged\n"
+ " spawn: avoids Qemu to spawn new threads or processes by blacklisting *fork and execve\n",
QEMU_ARCH_ALL)
STEXI
-@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}]
+@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@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'.
@@ -4018,6 +4019,8 @@ disable it. The default is 'off'.
Enable Obsolete system calls
@item elevateprivileges=@var{string}
Disable set*uid|gid systema calls
+@item spawn=@var{string}
+Disable *fork and execve
@end table
ETEXI
diff --git a/qemu-seccomp.c b/qemu-seccomp.c
index 6caa513edd..22a093ca1b 100644
--- a/qemu-seccomp.c
+++ b/qemu-seccomp.c
@@ -31,6 +31,12 @@ struct QemuSeccompSyscall {
uint8_t priority;
};
+static const struct QemuSeccompSyscall spawn_syscalls[] = {
+ { SCMP_SYS(fork), 255 },
+ { SCMP_SYS(vfork), 255 },
+ { SCMP_SYS(execve), 255 },
+};
+
static const struct QemuSeccompSyscall privileged_syscalls[] = {
{ SCMP_SYS(setuid), 255 },
{ SCMP_SYS(setgid), 255 },
@@ -138,6 +144,19 @@ int seccomp_start(uint8_t seccomp_opts)
}
}
+ if (seccomp_opts & SPAWN) {
+ for (i = 0; i < ARRAY_SIZE(spawn_syscalls); i++) {
+ rc = seccomp_rule_add(ctx, SCMP_ACT_KILL, spawn_syscalls[i].num, 0);
+ if (rc < 0) {
+ goto seccomp_return;
+ }
+ rc = seccomp_syscall_priority(ctx, spawn_syscalls[i].num,
+ spawn_syscalls[i].priority);
+ if (rc < 0) {
+ goto seccomp_return;
+ }
+ }
+ }
rc = seccomp_load(ctx);
diff --git a/vl.c b/vl.c
index f2b2f10b7b..ae3fa8b139 100644
--- a/vl.c
+++ b/vl.c
@@ -280,6 +280,10 @@ static QemuOptsList qemu_sandbox_opts = {
.name = "elevateprivileges",
.type = QEMU_OPT_STRING,
},
+ {
+ .name = "spawn",
+ .type = QEMU_OPT_STRING,
+ },
{ /* end of list */ }
},
};
@@ -1065,6 +1069,13 @@ static int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp)
}
}
+ value = qemu_opt_get(opts, "spawn");
+ if (value) {
+ if (strcmp(value, "deny") == 0) {
+ seccomp_opts |= SPAWN;
+ }
+ }
+
if (seccomp_start(seccomp_opts) < 0) {
error_report("failed to install seccomp syscall filter "
"in the kernel");
--
2.13.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH 5/6] seccomp: add resourcecontrol argument to command line
2017-07-21 12:52 [Qemu-devel] [PATCH v3 0/6] seccomp: feature refactoring Eduardo Otubo
` (3 preceding siblings ...)
2017-07-21 12:52 ` [Qemu-devel] [PATCH 4/6] seccomp: add spawn " Eduardo Otubo
@ 2017-07-21 12:52 ` Eduardo Otubo
2017-07-21 12:52 ` [Qemu-devel] [PATCH 6/6] seccomp: adding documentation to new seccomp model Eduardo Otubo
5 siblings, 0 replies; 8+ messages in thread
From: Eduardo Otubo @ 2017-07-21 12:52 UTC (permalink / raw)
To: qemu-devel
This patch adds [,resourcecontrol=deny] to `-sandbox on' option. It
blacklists all process affinity and scheduler priority system calls to
avoid any bigger of the process.
Signed-off-by: Eduardo Otubo <otubo@redhat.com>
---
include/sysemu/seccomp.h | 1 +
qemu-options.hx | 9 ++++++---
qemu-seccomp.c | 28 ++++++++++++++++++++++++++++
vl.c | 11 +++++++++++
4 files changed, 46 insertions(+), 3 deletions(-)
diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h
index f1614d6514..c7003dd197 100644
--- a/include/sysemu/seccomp.h
+++ b/include/sysemu/seccomp.h
@@ -18,6 +18,7 @@
#define OBSOLETE 0x0001
#define PRIVILEGED 0x0010
#define SPAWN 0x0100
+#define RESOURCECTL 0x1000
#include <seccomp.h>
diff --git a/qemu-options.hx b/qemu-options.hx
index 3d612f0fd1..7192236dee 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4004,13 +4004,14 @@ Old param mode (ARM only).
ETEXI
DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \
- "-sandbox on[,obsolete=allow][,elevateprivileges=allow|deny|children][,spawn=deny] Enable seccomp mode 2 system call filter (default 'off').\n" \
+ "-sandbox on[,obsolete=allow][,elevateprivileges=allow|deny|children][,spawn=deny][,resourcecontrol=deny] Enable seccomp mode 2 system call filter (default 'off').\n" \
" obsolete: Allow obsolete system calls\n"
" elevateprivileges: allows or denies Qemu process to elevate its privileges by blacklisting all set*uid|gid system calls. 'children' will deny set*uid|gid system calls for main Qemu process but will allow forks and execves to run unprivileged\n"
- " spawn: avoids Qemu to spawn new threads or processes by blacklisting *fork and execve\n",
+ " spawn: avoids Qemu to spawn new threads or processes by blacklisting *fork and execve\n"
+ " resourcecontrol: disable process affinity and schedular priority\n",
QEMU_ARCH_ALL)
STEXI
-@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}]
+@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}][,resourcecontrol=@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'.
@@ -4021,6 +4022,8 @@ Enable Obsolete system calls
Disable set*uid|gid systema calls
@item spawn=@var{string}
Disable *fork and execve
+@item resourcecontrol=@var{string}
+Disable process affinity and schedular priority
@end table
ETEXI
diff --git a/qemu-seccomp.c b/qemu-seccomp.c
index 22a093ca1b..95c8e31d1a 100644
--- a/qemu-seccomp.c
+++ b/qemu-seccomp.c
@@ -31,6 +31,19 @@ struct QemuSeccompSyscall {
uint8_t priority;
};
+static const struct QemuSeccompSyscall resourcecontrol_syscalls[] = {
+ { SCMP_SYS(getpriority), 255 },
+ { SCMP_SYS(setpriority), 255 },
+ { SCMP_SYS(sched_setparam), 255 },
+ { SCMP_SYS(sched_getparam), 255 },
+ { SCMP_SYS(sched_setscheduler), 255 },
+ { SCMP_SYS(sched_getscheduler), 255 },
+ { SCMP_SYS(sched_setaffinity), 255 },
+ { SCMP_SYS(sched_getaffinity), 255 },
+ { SCMP_SYS(sched_get_priority_max), 255 },
+ { SCMP_SYS(sched_get_priority_min), 255 },
+};
+
static const struct QemuSeccompSyscall spawn_syscalls[] = {
{ SCMP_SYS(fork), 255 },
{ SCMP_SYS(vfork), 255 },
@@ -158,6 +171,21 @@ int seccomp_start(uint8_t seccomp_opts)
}
}
+ if (seccomp_opts & RESOURCECTL) {
+ for (i = 0; i < ARRAY_SIZE(resourcecontrol_syscalls); i++) {
+ rc = seccomp_rule_add(ctx, SCMP_ACT_KILL,
+ resourcecontrol_syscalls[i].num, 0);
+ if (rc < 0) {
+ goto seccomp_return;
+ }
+ rc = seccomp_syscall_priority(ctx, resourcecontrol_syscalls[i].num,
+ resourcecontrol_syscalls[i].priority);
+ if (rc < 0) {
+ goto seccomp_return;
+ }
+ }
+ }
+
rc = seccomp_load(ctx);
seccomp_return:
diff --git a/vl.c b/vl.c
index ae3fa8b139..d9d4b025b9 100644
--- a/vl.c
+++ b/vl.c
@@ -284,6 +284,10 @@ static QemuOptsList qemu_sandbox_opts = {
.name = "spawn",
.type = QEMU_OPT_STRING,
},
+ {
+ .name = "resourcecontrol",
+ .type = QEMU_OPT_STRING,
+ },
{ /* end of list */ }
},
};
@@ -1076,6 +1080,13 @@ static int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp)
}
}
+ value = qemu_opt_get(opts, "resourcecontrol");
+ if (value) {
+ if (strcmp(value, "deny") == 0) {
+ seccomp_opts |= RESOURCECTL;
+ }
+ }
+
if (seccomp_start(seccomp_opts) < 0) {
error_report("failed to install seccomp syscall filter "
"in the kernel");
--
2.13.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH 6/6] seccomp: adding documentation to new seccomp model
2017-07-21 12:52 [Qemu-devel] [PATCH v3 0/6] seccomp: feature refactoring Eduardo Otubo
` (4 preceding siblings ...)
2017-07-21 12:52 ` [Qemu-devel] [PATCH 5/6] seccomp: add resourcecontrol " Eduardo Otubo
@ 2017-07-21 12:52 ` Eduardo Otubo
5 siblings, 0 replies; 8+ messages in thread
From: Eduardo Otubo @ 2017-07-21 12:52 UTC (permalink / raw)
To: qemu-devel
Adding new documention under docs/ to describe every one and each new
option added by the refactoring patchset.
Signed-off-by: Eduardo Otubo <otubo@redhat.com>
---
docs/seccomp.txt | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
create mode 100644 docs/seccomp.txt
diff --git a/docs/seccomp.txt b/docs/seccomp.txt
new file mode 100644
index 0000000000..4b7edba312
--- /dev/null
+++ b/docs/seccomp.txt
@@ -0,0 +1,31 @@
+QEMU Seccomp system call filter
+===============================
+
+Starting from Qemu version 2.10, the seccomp filter does not work as a
+whitelist but as a blacklist instead. This method allows safer deploys since
+only the strictly forbidden system calls will be black-listed and the
+possibility of breaking any workload is close to zero.
+
+The default option (-sandbox on) has a slightly looser security though and the
+reason is that it shouldn't break any backwards compatibility with previous
+deploys and command lines already running. But if the intent is to have a
+better security from this version on, one should make use of the following
+additional options properly:
+
+* [,obsolete=allow]: It allows Qemu to run safely on old system that still
+ relies on old system calls.
+
+* [,elevateprivileges=deny|allow|children]: It allows or denies Qemu process
+ to elevate its privileges by blacklisting all set*uid|gid system calls. The
+ 'children' option sets the PR_SET_NO_NEW_PRIVS to 1 which allows helpers
+ (forls and execs) to run unprivileged.
+
+* [,spawn=deny]: It blacklists fork and execve syste calls, avoiding Qemu to
+ spawn new threads or processes.
+
+* [,resourcecontrol=deny]: It blacklists all process affinity and scheduler
+ priority system calls to avoid any bigger of the process.
+
+
+--
+Eduardo Otubo <otubo@redhat.com>
--
2.13.3
^ permalink raw reply related [flat|nested] 8+ messages in thread
end of thread, other threads:[~2017-07-21 12:52 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-07-21 12:52 [Qemu-devel] [PATCH v3 0/6] seccomp: feature refactoring Eduardo Otubo
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2017-07-21 12:52 ` [Qemu-devel] [PATCH 2/6] seccomp: add obsolete argument to command line Eduardo Otubo
2017-07-21 12:52 ` [Qemu-devel] [PATCH 3/6] seccomp: add elevateprivileges " Eduardo Otubo
2017-07-21 12:52 ` [Qemu-devel] [PATCH 4/6] seccomp: add spawn " Eduardo Otubo
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