[RFC 5/8] v4l2-async: Safely clean up an uninitialised notifier

[Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>]

Make the V4L2 async framework a bit more robust by allowing to clean up an
uninitialised notifier. Otherwise the result would be a (close to) NULL
pointer dereference.

Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
 drivers/media/v4l2-core/v4l2-async.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index 9c1937d6ce17..b1a37a8be22a 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -537,7 +537,7 @@ static void __v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
 {
 	struct v4l2_async_subdev *asd, *tmp;
 
-	if (!notifier)
+	if (!notifier || !notifier->asd_list.next)
 		return;
 
 	list_for_each_entry_safe(asd, tmp, &notifier->asd_list, asd_list) {
-- 
2.11.0