4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Phil Chang <phil.chang@xxxxxxxxxxxx> [ Upstream commit 5a830bbce3af16833fe0092dec47b6dd30279825 ] The hrtimer function callback must not be NULL. It has to be specified by the call side but it is not validated by the hrtimer code. When a hrtimer is queued without a function callback, the kernel crashes with a null pointer dereference when trying to execute the callback in __run_hrtimer(). Introduce a validation before queuing the hrtimer in hrtimer_start_range_ns(). [anna-maria: Rephrase commit message] Signed-off-by: Phil Chang <phil.chang@xxxxxxxxxxxx> Signed-off-by: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Reviewed-by: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- kernel/time/hrtimer.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 0eb5b6cc6d939..b600dc1290d7e 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1172,6 +1172,8 @@ void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, struct hrtimer_clock_base *base; unsigned long flags; + if (WARN_ON_ONCE(!timer->function)) + return; /* * Check whether the HRTIMER_MODE_SOFT bit and hrtimer.is_soft * match. -- 2.43.0
