Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 79ef2bb0 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

clocksource: Prevent NULL pointer dereference 



Writing a zero length string to sys/.../current_clocksource will cause
a NULL pointer dereference if the clock events system is in one shot
(highres or nohz) mode.

Pointed-out-by: default avatarDan Carpenter <error27@gmail.com>
LKML-Reference: <alpine.DEB.2.00.0907191545580.12306@bicker>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 4841158b

kernel/time/clocksource.c

+1 −1
Original line number Diff line number Diff line
@@ -513,7 +513,7 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev, 
	 * Check to make sure we don't switch to a non-highres capable

	 * clocksource if the tick code is in oneshot mode (highres or nohz)

	 */

	if (tick_oneshot_mode_active() &&

	if (tick_oneshot_mode_active() && ovr &&

	    !(ovr->flags & CLOCK_SOURCE_VALID_FOR_HRES)) {

		printk(KERN_WARNING "%s clocksource is not HRT compatible. "

			"Cannot switch while in HRT/NOHZ mode\n", ovr->name);