fix race between exit_itimers() and /proc/pid/timers
commit d5b36a4dbd06c5e8e36ca8ccc552f679069e2946 upstream.
As Chris explains, the comment above exit_itimers() is not correct,
we can race with proc_timers_seq_ops. Change exit_itimers() to clear
signal->posix_timers with ->siglock held.
Cc: <stable@vger.kernel.org>
Reported-by: chris@accessvector.net
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/exec.c b/fs/exec.c
index 29e865c..76196dd 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1298,7 +1298,7 @@ int begin_new_exec(struct linux_binprm * bprm)
bprm->mm = NULL;
#ifdef CONFIG_POSIX_TIMERS
- exit_itimers(me->signal);
+ exit_itimers(me);
flush_itimer_signals();
#endif