shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-07 19:30:30 +09:00
Code Issues Packages Projects Releases Wiki Activity

watchdog: core: fix null pointer dereference when releasing cdev

Browse Source 
[ Upstream commit 953b9dd772 ]

watchdog_stop() calls watchdog_update_worker() which needs a valid
wdd->wd_data pointer. So, when unregistering the cdev, clear the
pointers after we call watchdog_stop(), not before.

Fixes: bb292ac1c6 ("watchdog: Introduce watchdog_stop_on_unregister helper")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
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>
This commit is contained in:
Wolfram Sang
2018-08-28 12:13:47 +02:00
committed by Greg Kroah-Hartman
parent a9f36455ed
commit f4cfb7eeae
1 changed files with 5 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/watchdog/watchdog_dev.c
View File

@@ -1019,16 +1019,16 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd)
old_wd_data = NULL;
}
mutex_lock(&wd_data->lock);
wd_data->wdd = NULL;
wdd->wd_data = NULL;
mutex_unlock(&wd_data->lock);
if (watchdog_active(wdd) &&
test_bit(WDOG_STOP_ON_UNREGISTER, &wdd->status)) {
watchdog_stop(wdd);
}
mutex_lock(&wd_data->lock);
wd_data->wdd = NULL;
wdd->wd_data = NULL;
mutex_unlock(&wd_data->lock);
hrtimer_cancel(&wd_data->timer);
kthread_cancel_work_sync(&wd_data->work);