Commit 86d37bf3 authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Mauro Carvalho Chehab
Browse files

media: i2c: max9286: Allocate v4l2_async_subdev dynamically 



v4l2_async_notifier_add_subdev() requires the asd to be allocated
dynamically, but the max9286 driver embeds it in the max9286_source
structure. This causes memory corruption when the notifier is destroyed
at remove time with v4l2_async_notifier_cleanup().

Fix this issue by registering the asd with
v4l2_async_notifier_add_fwnode_subdev(), which allocates it dynamically
internally. A new max9286_asd structure is introduced, to store a
pointer to the corresonding max9286_source that needs to be accessed
from bound and unbind callbacks. There's no need to take an extra
explicit reference to the fwnode anymore as
v4l2_async_notifier_add_fwnode_subdev() does so internally.

While at it, use %u instead of %d to print the unsigned index in the
error message from the v4l2_async_notifier_add_fwnode_subdev() error
path.

Fixes: 66d8c9d2 ("media: i2c: Add MAX9286 driver")
Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent 2cac7cbf

drivers/media/i2c/max9286.c

+21 −19
Original line number Diff line number Diff line
@@ -135,13 +135,19 @@ 
#define MAX9286_SRC_PAD			4



struct max9286_source {

	struct v4l2_async_subdev asd;

	struct v4l2_subdev *sd;

	struct fwnode_handle *fwnode;

};



#define asd_to_max9286_source(_asd) \

	container_of(_asd, struct max9286_source, asd)

struct max9286_asd {

	struct v4l2_async_subdev base;

	struct max9286_source *source;

};



static inline struct max9286_asd *to_max9286_asd(struct v4l2_async_subdev *asd)

{

	return container_of(asd, struct max9286_asd, base);

}



struct max9286_priv {

	struct i2c_client *client;
@@ -481,7 +487,7 @@ static int max9286_notify_bound(struct v4l2_async_notifier *notifier, 
				struct v4l2_async_subdev *asd)

{

	struct max9286_priv *priv = sd_to_max9286(notifier->sd);

	struct max9286_source *source = asd_to_max9286_source(asd);

	struct max9286_source *source = to_max9286_asd(asd)->source;

	unsigned int index = to_index(priv, source);

	unsigned int src_pad;

	int ret;
@@ -545,7 +551,7 @@ static void max9286_notify_unbind(struct v4l2_async_notifier *notifier, 
				  struct v4l2_async_subdev *asd)

{

	struct max9286_priv *priv = sd_to_max9286(notifier->sd);

	struct max9286_source *source = asd_to_max9286_source(asd);

	struct max9286_source *source = to_max9286_asd(asd)->source;

	unsigned int index = to_index(priv, source);



	source->sd = NULL;
@@ -570,23 +576,19 @@ static int max9286_v4l2_notifier_register(struct max9286_priv *priv) 


	for_each_source(priv, source) {

		unsigned int i = to_index(priv, source);

		struct v4l2_async_subdev *asd;



		source->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;

		source->asd.match.fwnode = source->fwnode;



		ret = v4l2_async_notifier_add_subdev(&priv->notifier,

						     &source->asd);

		if (ret) {

			dev_err(dev, "Failed to add subdev for source %d", i);

		asd = v4l2_async_notifier_add_fwnode_subdev(&priv->notifier,

							    source->fwnode,

							    sizeof(*asd));

		if (IS_ERR(asd)) {

			dev_err(dev, "Failed to add subdev for source %u: %ld",

				i, PTR_ERR(asd));

			v4l2_async_notifier_cleanup(&priv->notifier);

			return ret;

			return PTR_ERR(asd);

		}



		/*

		 * Balance the reference counting handled through

		 * v4l2_async_notifier_cleanup()

		 */

		fwnode_handle_get(source->fwnode);

		to_max9286_asd(asd)->source = source;

	}



	priv->notifier.ops = &max9286_notify_ops;

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