A few lines before 'watchdog_hrtimer_pretimeout_stop(wdd)', we explicitly set 'wdd->wd_data' to NULL. So, it is more than likely than this call will lead to an invalid memory access. Move this call before the 'wdd->wd_data = NULL;' Fixes: 7b7d2fdc8c3e ("watchdog: Add hrtimer-based pretimeout feature") Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> --- Completely untested! Not sure at all, that it is the way to fix it. --- drivers/watchdog/watchdog_dev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index 3bab32485273..ffd8f1a82355 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -1096,6 +1096,8 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd) watchdog_stop(wdd); } + watchdog_hrtimer_pretimeout_stop(wdd); + mutex_lock(&wd_data->lock); wd_data->wdd = NULL; wdd->wd_data = NULL; @@ -1103,7 +1105,6 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd) hrtimer_cancel(&wd_data->timer); kthread_cancel_work_sync(&wd_data->work); - watchdog_hrtimer_pretimeout_stop(wdd); put_device(&wd_data->dev); } -- 2.30.2