This is a note to let you know that I've just added the patch titled
hrtimer: Prevent queuing of hrtimer without a function callback
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
hrtimer-prevent-queuing-of-hrtimer-without-a-functio.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3b235d37b2d97bbcc87699a30b4a73d96559c110
Author: Phil Chang <phil.chang@xxxxxxxxxxxx>
Date: Mon Jun 10 21:31:36 2024 +0800
hrtimer: Prevent queuing of hrtimer without a function callback
[ 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>
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.
