On 7/29/21 9:16 AM, Christophe JAILLET wrote:
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.
Nice catch. Should be ok.
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
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);
}
