From: Sakari Ailus <sakari.ailus@linux.intel.com>
Date: Mon, 4 Mar 2019 09:29:49 +0000 (-0500)
Subject: media: v4l2-async: Safely clean up an uninitialised notifier
X-Git-Tag: v5.15~5520^2~215
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d1e164289e55de90fcc5680f459a43972430a28d;p=platform%2Fkernel%2Flinux-starfive.git

media: v4l2-async: Safely clean up an uninitialised notifier

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@linux.intel.com>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index dc4f470..8bde33c 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -534,7 +534,7 @@ 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) {