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: b25e67161c ("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>
This commit is contained in:
Kees Cook 2017-02-07 15:18:51 -08:00 committed by James Morris
parent 37c85961c3
commit d7276e321f
1 changed files with 8 additions and 5 deletions

View File

@ -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);
/* 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);
/* 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);
}
}