From 1453ad81a2be1bef9243671480694d483ab0dad0 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Niklas=20S=C3=B6derlund?=
<niklas.soderlund+renesas@ragnatech.se>
Date: Fri, 3 Nov 2017 22:25:56 -0400
Subject: [PATCH] media: v4l: async: fix unregister for implicitly registered
sub-device notifiers
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit
The commit aef69d54755d45ed ("media: v4l: fwnode: Add a convenience
function for registering sensors") adds the function
v4l2_async_notifier_parse_fwnode_sensor_common() to parse and register a
subdevice and a subdev-notifier by parsing firmware information. This
new subdev-notifier is stored in the new field 'subdev_notifier' in
struct v4l2_subdev.
In v4l2_async_unregister_subdev() this field is used to unregister and
cleanup the subdev-notifier. A check for if the subdev-notifier is
initialized or not was forgotten leading to a NULL pointer dereference
in v4l2_async_notifier_cleanup() if a subdevice do not use the optional
convince function to initialize the field.
Fix this by checking in v4l2_async_notifier_cleanup() that it is
provided whit a notifier making it safe to call with a NULL parameter.
Fixes: aef69d54755d45ed ("media: v4l: fwnode: Add a convenience function for registering sensors")
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
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 7020b2e6d158a..a7c3464976f24 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -502,7 +502,7 @@ void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
{
unsigned int i;
- if (!notifier->max_subdevs)
+ if (!notifier || !notifier->max_subdevs)
return;
for (i = 0; i < notifier->num_subdevs; i++) {
--
2.30.2