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authorThomas Gleixner <tglx@linutronix.de>2016-12-15 12:10:37 +0100
committerThomas Gleixner <tglx@linutronix.de>2016-12-15 12:25:13 +0100
commitc1a9eeb938b5433947e5ea22f89baff3182e7075 (patch)
treeb6ebcc09e7d73f78a5f57b1e0ad796655f23586f /kernel/time
parentf082f02c4731900a5065de69eb0d8cb5aab66196 (diff)
downloadlinux-c1a9eeb938b5433947e5ea22f89baff3182e7075.tar.bz2
tick/broadcast: Prevent NULL pointer dereference
When a disfunctional timer, e.g. dummy timer, is installed, the tick core tries to setup the broadcast timer. If no broadcast device is installed, the kernel crashes with a NULL pointer dereference in tick_broadcast_setup_oneshot() because the function has no sanity check. Reported-by: Mason <slash.tmp@free.fr> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Anna-Maria Gleixner <anna-maria@linutronix.de> Cc: Richard Cochran <rcochran@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org>, Cc: Sebastian Frias <sf84@laposte.net> Cc: Thibaud Cornic <thibaud_cornic@sigmadesigns.com> Cc: Robin Murphy <robin.murphy@arm.com> Link: http://lkml.kernel.org/r/1147ef90-7877-e4d2-bb2b-5c4fa8d3144b@free.fr
Diffstat (limited to 'kernel/time')
-rw-r--r--kernel/time/tick-broadcast.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index f6aae7977824..d2a20e83ebae 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -871,6 +871,9 @@ void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
{
int cpu = smp_processor_id();
+ if (!bc)
+ return;
+
/* Set it up only once ! */
if (bc->event_handler != tick_handle_oneshot_broadcast) {
int was_periodic = clockevent_state_periodic(bc);