Commit d7276e32 authored Feb 07, 2017 by Kees Cook Committed by James Morris Feb 23, 2017

seccomp: Only dump core when single-threaded

The SECCOMP_RET_KILL filter return code has always killed the current
thread, not the entire process. Changing this as a side-effect of dumping
core isn't a safe thing to do (a few test suites have already flagged this
behavioral change). Instead, restore the RET_KILL semantics, but still
dump core when a RET_KILL delivers SIGSYS to a single-threaded process.

Fixes: b25e6716 ("seccomp: dump core when using SECCOMP_RET_KILL")
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

parent 37c85961

kernel/seccomp.c

+8 −5

Original line number	Diff line number	Diff line
		@@ -643,11 +643,14 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
		default: {
		siginfo_t info;
		audit_seccomp(this_syscall, SIGSYS, action);
		/* Dump core only if this is the last remaining thread. */
		if (get_nr_threads(current) == 1) {
		/* Show the original registers in the dump. */
		syscall_rollback(current, task_pt_regs(current));
		/* Trigger a manual coredump since do_exit skips it. */
		seccomp_init_siginfo(&info, this_syscall, data);
		do_coredump(&info);
		}
		do_exit(SIGSYS);
		}
		}

Admin message