From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Zou Wei <zou_wei@huawei.com>, Hulk Robot <hulkci@huawei.com>,
Guenter Roeck <linux@roeck-us.net>,
Wim Van Sebroeck <wim@linux-watchdog.org>,
Sasha Levin <sashal@kernel.org>,
linux-watchdog@vger.kernel.org
Subject: [PATCH AUTOSEL 5.10 14/37] watchdog: Fix possible use-after-free in wdt_startup()
Date: Sat, 10 Jul 2021 19:49:52 -0400 [thread overview]
Message-ID: <20210710235016.3221124-14-sashal@kernel.org> (raw)
In-Reply-To: <20210710235016.3221124-1-sashal@kernel.org>
From: Zou Wei <zou_wei@huawei.com>
[ 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>
---
drivers/watchdog/sbc60xxwdt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
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");
}
--
2.30.2
next parent reply other threads:[~2021-07-10 23:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210710235016.3221124-1-sashal@kernel.org>
2021-07-10 23:49 ` Sasha Levin [this message]
2021-07-10 23:49 ` [PATCH AUTOSEL 5.10 15/37] watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff() Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.10 16/37] watchdog: Fix possible use-after-free by calling del_timer_sync() Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.10 17/37] watchdog: imx_sc_wdt: fix pretimeout Sasha Levin
2021-07-10 23:49 ` [PATCH AUTOSEL 5.10 18/37] watchdog: iTCO_wdt: Account for rebooting on second timeout Sasha Levin
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