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[Qemu-devel] [PATCH v2 1/2] seccomp: use SIGSYS signal instead of killin
From: |
Marc-André Lureau |
Subject: |
[Qemu-devel] [PATCH v2 1/2] seccomp: use SIGSYS signal instead of killing the thread |
Date: |
Thu, 16 Aug 2018 15:04:14 +0200 |
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 <address@hidden>
Reviewed-by: Daniel P. Berrangé <address@hidden>
Acked-by: Eduardo Otubo <address@hidden>
---
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