alarmtimers: Avoid possible null pointer traversal
commit 971c90bfa2f0b4fe52d6d9002178d547706f1343 upstream.
We don't check if old_setting is non null before assigning it, so
correct this.
CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 59f369f..1dee3f6 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -479,11 +479,8 @@
if (!rtcdev)
return -ENOTSUPP;
- /* Save old values */
- old_setting->it_interval =
- ktime_to_timespec(timr->it.alarmtimer.period);
- old_setting->it_value =
- ktime_to_timespec(timr->it.alarmtimer.node.expires);
+ if (old_setting)
+ alarm_timer_get(timr, old_setting);
/* If the timer was already set, cancel it */
alarm_cancel(&timr->it.alarmtimer);