The seccomp action SCMP_ACT_KILL results in immediate termination of the thread that made the bad system call. However, qemu being multi-threaded, it keeps running. There is no easy way for parent process / management layer (libvirt) to know about that situation.
Instead, the default SIGSYS handler when invoked with SCMP_ACT_TRAP will terminate the program and core dump. This may not be the most secure solution, but probably better than just killing the offending thread. SCMP_ACT_KILL_PROCESS has been added in Linux 4.14 to improve the situation, which I propose to use by default if available in the next patch. Related to: https://bugzilla.redhat.com/show_bug.cgi?id=1594456 Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com> Reviewed-by: Daniel P. Berrangé <berra...@redhat.com> Acked-by: Eduardo Otubo <ot...@redhat.com> --- qemu-seccomp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/qemu-seccomp.c b/qemu-seccomp.c index 9cd8eb9499..b117a92559 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -125,7 +125,7 @@ static int seccomp_start(uint32_t seccomp_opts) continue; } - rc = seccomp_rule_add_array(ctx, SCMP_ACT_KILL, blacklist[i].num, + rc = seccomp_rule_add_array(ctx, SCMP_ACT_TRAP, blacklist[i].num, blacklist[i].narg, blacklist[i].arg_cmp); if (rc < 0) { goto seccomp_return; -- 2.18.0.547.g1d89318c48
