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authorZou Wei <zou_wei@huawei.com>2021-05-11 15:01:35 +0800
committerWim Van Sebroeck <wim@linux-watchdog.org>2021-06-21 08:48:59 +0200
commitc08a6b31e4917034f0ed0cb457c3bb209576f542 (patch)
treebeb9eafd7ed9335d31aa2c9ec6af662d7da8b644
parente0b101ab01c719a5a81b21ff16bbd33a868f9189 (diff)
downloadlinux-c08a6b31e4917034f0ed0cb457c3bb209576f542.tar.bz2
watchdog: Fix possible use-after-free in wdt_startup()
This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Zou Wei <zou_wei@huawei.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/1620716495-108352-1-git-send-email-zou_wei@huawei.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
-rw-r--r--drivers/watchdog/sbc60xxwdt.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/watchdog/sbc60xxwdt.c b/drivers/watchdog/sbc60xxwdt.c
index a947a63fb44a..7b974802dfc7 100644
--- a/drivers/watchdog/sbc60xxwdt.c
+++ b/drivers/watchdog/sbc60xxwdt.c
@@ -146,7 +146,7 @@ static void wdt_startup(void)
static void wdt_turnoff(void)
{
/* Stop the timer */
- del_timer(&timer);
+ del_timer_sync(&timer);
inb_p(wdt_stop);
pr_info("Watchdog timer is now disabled...\n");
}