This is a note to let you know that I've just added the patch titled
watchdog: cpu5wdt.c: Fix use-after-free bug caused by cpu5wdt_trigger
to the 6.9-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:
watchdog-cpu5wdt.c-fix-use-after-free-bug-caused-by-.patch
and it can be found in the queue-6.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cdd45c26c8e3437f90ad92417332b98f66b334d3
Author: Duoming Zhou <duoming@xxxxxxxxxx>
Date: Sun Mar 24 22:04:44 2024 +0800
watchdog: cpu5wdt.c: Fix use-after-free bug caused by cpu5wdt_trigger
[ Upstream commit 573601521277119f2e2ba5f28ae6e87fc594f4d4 ]
When the cpu5wdt module is removing, the origin code uses del_timer() to
de-activate the timer. If the timer handler is running, del_timer() could
not stop it and will return directly. If the port region is released by
release_region() and then the timer handler cpu5wdt_trigger() calls outb()
to write into the region that is released, the use-after-free bug will
happen.
Change del_timer() to timer_shutdown_sync() in order that the timer handler
could be finished before the port region is released.
Fixes: e09d9c3e9f85 ("watchdog: cpu5wdt.c: add missing del_timer call")
Signed-off-by: Duoming Zhou <duoming@xxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240324140444.119584-1-duoming@xxxxxxxxxx
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/watchdog/cpu5wdt.c b/drivers/watchdog/cpu5wdt.c
index 688b112e712ba..9f279c0e13a66 100644
--- a/drivers/watchdog/cpu5wdt.c
+++ b/drivers/watchdog/cpu5wdt.c
@@ -252,7 +252,7 @@ static void cpu5wdt_exit(void)
if (cpu5wdt_device.queue) {
cpu5wdt_device.queue = 0;
wait_for_completion(&cpu5wdt_device.stop);
- del_timer(&cpu5wdt_device.timer);
+ timer_shutdown_sync(&cpu5wdt_device.timer);
}
misc_deregister(&cpu5wdt_misc);
