summary refs log tree commit diff stats
path: root/qemu-seccomp.c
diff options
context:
space:
mode:
authorMarc-André Lureau <marcandre.lureau@redhat.com>2018-08-22 19:02:47 +0200
committerEduardo Otubo <otubo@redhat.com>2018-08-23 16:45:20 +0200
commit6f2231e9b0931e1998d9ed0c509adf7aedc02db2 (patch)
tree62e40bd7df6af9eae13d636c65b111ae72621022 /qemu-seccomp.c
parent3392fbee4e435658733bbe9aab23392660558b59 (diff)
downloadfocaccia-qemu-6f2231e9b0931e1998d9ed0c509adf7aedc02db2.tar.gz
focaccia-qemu-6f2231e9b0931e1998d9ed0c509adf7aedc02db2.zip
seccomp: use SIGSYS signal instead of killing the thread
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.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Eduardo Otubo <otubo@redhat.com>
Diffstat (limited to 'qemu-seccomp.c')
-rw-r--r--qemu-seccomp.c2
1 files changed, 1 insertions, 1 deletions
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;