Hi, 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. Related to: https://bugzilla.redhat.com/show_bug.cgi?id=1594456 Marc-André Lureau (2): seccomp: use SIGSYS signal instead of killing the thread RFC: seccomp: prefer SCMP_ACT_KILL_PROCESS if available qemu-seccomp.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) -- 2.18.0.232.gb7bd9486b0
