diff options
| author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2018-08-28 12:13:47 +0200 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@linux-watchdog.org> | 2018-10-02 13:32:24 +0200 |
| commit | 953b9dd7725bad55a922a35e75bff7bebf7b9978 (patch) | |
| tree | 21362448aa15c3147f1cb97e5a07863632602e5b /drivers/watchdog | |
| parent | 3bed02a2966146b5876b366f4489e30af0547c66 (diff) | |
| download | linux-953b9dd7725bad55a922a35e75bff7bebf7b9978.tar.gz | |
watchdog: core: fix null pointer dereference when releasing cdev
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: bb292ac1c602 ("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>
Diffstat (limited to 'drivers/watchdog')
| -rw-r--r-- | drivers/watchdog/watchdog_dev.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index ffbdc4642ea5..f6c24b22b37c 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -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); |