time: Make sure tz_minuteswest is set to a valid value when setting time

Invalid values may overflow later, leading to undefined behaviour when multiplied by 60 to get the amount of seconds. Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: John Stultz <[email protected]>
opensourcefreak · May 22, 2015 · 6f7d798 · 6f7d798
1 parent 4e3d9cb
commit 6f7d798
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/kernel/time/time.c b/kernel/time/time.c
@@ -173,6 +173,10 @@ int do_sys_settimeofday(const struct timespec *tv, const struct timezone *tz)
 		return error;
 
 	if (tz) {
+		/* Verify we're witin the +-15 hrs range */
+		if (tz->tz_minuteswest > 15*60 || tz->tz_minuteswest < -15*60)
+			return -EINVAL;
+
 		sys_tz = *tz;
 		update_vsyscall_tz();
 		if (firsttime) {