5.4-stable review patch. If anyone has any objections, please let me know.
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From: Phil Chang phil.chang@mediatek.com
[ 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@mediatek.com Signed-off-by: Anna-Maria Behnsen anna-maria@linutronix.de Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Anna-Maria Behnsen anna-maria@linutronix.de Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/time/hrtimer.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 1b301dd1692b8..2e4f136bdf6ab 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1183,6 +1183,8 @@ 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 on CONFIG_PREEMPT_RT = n. With PREEMPT_RT check the hard