From: Phil Chang <phil.chang@mediatek.com> stable inclusion from stable-v4.19.321 commit ccef3adcb84816a30b8e535c8c4fcb167904e7b1 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAYQRI CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> --- kernel/time/hrtimer.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 8512f06f0ebe..ce8fe5adafb0 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1171,6 +1171,8 @@ 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. -- 2.20.1