From: John Stultz <john.stultz@linaro.org>
Date: Thu, 4 Aug 2011 14:25:35 +0000 (-0700)
Subject: alarmtimers: Avoid possible null pointer traversal
X-Git-Tag: v3.0.5~184
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=26cf1a7ba1a6cc19d48c993bebd3be94c48af74a;p=karo-tx-linux.git

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 59f369f98a04..1dee3f62a6a7 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -479,11 +479,8 @@ static int alarm_timer_set(struct k_itimer *timr, int flags,
 	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);