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authorZou Wei <zou_wei@huawei.com>2021-05-11 15:01:35 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-07-20 16:21:13 +0200
commit862f2b5a7c38762ac9e369daefbf361a91aca685 (patch)
tree25d9557cb711b46bc2fced24dc808501b924efb7
parent5429800d6516dc7853153d502453ce312dcc4815 (diff)
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watchdog: Fix possible use-after-free in wdt_startup()
[ Upstream commit c08a6b31e4917034f0ed0cb457c3bb209576f542 ] 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> Signed-off-by: Sasha Levin <sashal@kernel.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 2eef58a0cf05..152db059d5aa 100644
--- a/drivers/watchdog/sbc60xxwdt.c
+++ b/drivers/watchdog/sbc60xxwdt.c
@@ -152,7 +152,7 @@ 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");
}