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>
---
drivers/watchdog/cpu5wdt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/watchdog/cpu5wdt.c b/drivers/watchdog/cpu5wdt.c
index 688b112e712..9f279c0e13a 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);
--
2.17.1
