[tip:timers/urgent] posix_cpu_timer: Exit early when process has been reaped

[tip-bot for Alexey Dobriyan <tipbot@zytor.com>]

Commit-ID:  2c13ce8f6b2f6fd9ba2f9261b1939fc0f62d1307
Gitweb:     http://git.kernel.org/tip/2c13ce8f6b2f6fd9ba2f9261b1939fc0f62d1307
Author:     Alexey Dobriyan <adobriyan@gmail.com>
AuthorDate: Fri, 8 Jul 2016 01:39:11 +0300
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 11 Jul 2016 17:20:12 +0200

posix_cpu_timer: Exit early when process has been reaped

Variable "now" seems to be genuinely used unintialized
if branch

	if (CPUCLOCK_PERTHREAD(timer->it_clock)) {

is not taken and branch

	if (unlikely(sighand == NULL)) {

is taken. In this case the process has been reaped and the timer is marked as
disarmed anyway. So none of the postprocessing of the sample is
required. Return right away.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20160707223911.GA26483@p183.telecom.by
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/time/posix-cpu-timers.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 1cafba8..39008d7 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -777,6 +777,7 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
 			timer->it.cpu.expires = 0;
 			sample_to_timespec(timer->it_clock, timer->it.cpu.expires,
 					   &itp->it_value);
+			return;
 		} else {
 			cpu_timer_sample_group(timer->it_clock, p, &now);
 			unlock_task_sighand(p, &flags);