diff mbox series

[3/5] media: rcar_drif: Allocate v4l2_async_subdev dynamically

Message ID 20200811205939.19550-4-laurent.pinchart+renesas@ideasonboard.com (mailing list archive)
State New, archived
Headers show
Series media: Fix asd dynamic allocation | expand

Commit Message

Laurent Pinchart Aug. 11, 2020, 8:59 p.m. UTC
v4l2_async_notifier_add_subdev() requires the asd to be allocated
dynamically, but the rcar-drif driver embeds it in the
rcar_drif_graph_ep 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.

Fixes: d079f94c9046 ("media: platform: Switch to v4l2_async_notifier_add_subdev")
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
 drivers/media/platform/rcar_drif.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

Comments

Kieran Bingham Sept. 16, 2020, 3:53 p.m. UTC | #1
Hi Laurent,

On 11/08/2020 21:59, Laurent Pinchart wrote:
> v4l2_async_notifier_add_subdev() requires the asd to be allocated
> dynamically, but the rcar-drif driver embeds it in the
> rcar_drif_graph_ep 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.
> 
> Fixes: d079f94c9046 ("media: platform: Switch to v4l2_async_notifier_add_subdev")
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>


> ---
>  drivers/media/platform/rcar_drif.c | 18 ++++++------------
>  1 file changed, 6 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/media/platform/rcar_drif.c b/drivers/media/platform/rcar_drif.c
> index 3f1e5cb8b197..f318cd4b8086 100644
> --- a/drivers/media/platform/rcar_drif.c
> +++ b/drivers/media/platform/rcar_drif.c
> @@ -185,7 +185,6 @@ struct rcar_drif_frame_buf {
>  /* OF graph endpoint's V4L2 async data */
>  struct rcar_drif_graph_ep {
>  	struct v4l2_subdev *subdev;	/* Async matched subdev */
> -	struct v4l2_async_subdev asd;	/* Async sub-device descriptor */
>  };
>  
>  /* DMA buffer */
> @@ -1109,12 +1108,6 @@ static int rcar_drif_notify_bound(struct v4l2_async_notifier *notifier,
>  	struct rcar_drif_sdr *sdr =
>  		container_of(notifier, struct rcar_drif_sdr, notifier);
>  
> -	if (sdr->ep.asd.match.fwnode !=
> -	    of_fwnode_handle(subdev->dev->of_node)) {
> -		rdrif_err(sdr, "subdev %s cannot bind\n", subdev->name);
> -		return -EINVAL;
> -	}
> -
>  	v4l2_set_subdev_hostdata(subdev, sdr);
>  	sdr->ep.subdev = subdev;
>  	rdrif_dbg(sdr, "bound asd %s\n", subdev->name);
> @@ -1218,7 +1211,7 @@ static int rcar_drif_parse_subdevs(struct rcar_drif_sdr *sdr)
>  {
>  	struct v4l2_async_notifier *notifier = &sdr->notifier;
>  	struct fwnode_handle *fwnode, *ep;
> -	int ret;
> +	struct v4l2_async_subdev *asd;
>  
>  	v4l2_async_notifier_init(notifier);
>  
> @@ -1237,12 +1230,13 @@ static int rcar_drif_parse_subdevs(struct rcar_drif_sdr *sdr)
>  		return -EINVAL;
>  	}
>  
> -	sdr->ep.asd.match.fwnode = fwnode;
> -	sdr->ep.asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
> -	ret = v4l2_async_notifier_add_subdev(notifier, &sdr->ep.asd);
> +	asd = v4l2_async_notifier_add_fwnode_subdev(notifier, fwnode,
> +						    sizeof(*asd));

I guess this isn't suffering from the same thing that happened on the
max9286 as there is no need for any private data to follow here.

So,

Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

>  	fwnode_handle_put(fwnode);
> +	if (IS_ERR(asd))
> +		return PTR_ERR(asd);
>  
> -	return ret;
> +	return 0;
>  }
>  
>  /* Check if the given device is the primary bond */
>
diff mbox series

Patch

diff --git a/drivers/media/platform/rcar_drif.c b/drivers/media/platform/rcar_drif.c
index 3f1e5cb8b197..f318cd4b8086 100644
--- a/drivers/media/platform/rcar_drif.c
+++ b/drivers/media/platform/rcar_drif.c
@@ -185,7 +185,6 @@  struct rcar_drif_frame_buf {
 /* OF graph endpoint's V4L2 async data */
 struct rcar_drif_graph_ep {
 	struct v4l2_subdev *subdev;	/* Async matched subdev */
-	struct v4l2_async_subdev asd;	/* Async sub-device descriptor */
 };
 
 /* DMA buffer */
@@ -1109,12 +1108,6 @@  static int rcar_drif_notify_bound(struct v4l2_async_notifier *notifier,
 	struct rcar_drif_sdr *sdr =
 		container_of(notifier, struct rcar_drif_sdr, notifier);
 
-	if (sdr->ep.asd.match.fwnode !=
-	    of_fwnode_handle(subdev->dev->of_node)) {
-		rdrif_err(sdr, "subdev %s cannot bind\n", subdev->name);
-		return -EINVAL;
-	}
-
 	v4l2_set_subdev_hostdata(subdev, sdr);
 	sdr->ep.subdev = subdev;
 	rdrif_dbg(sdr, "bound asd %s\n", subdev->name);
@@ -1218,7 +1211,7 @@  static int rcar_drif_parse_subdevs(struct rcar_drif_sdr *sdr)
 {
 	struct v4l2_async_notifier *notifier = &sdr->notifier;
 	struct fwnode_handle *fwnode, *ep;
-	int ret;
+	struct v4l2_async_subdev *asd;
 
 	v4l2_async_notifier_init(notifier);
 
@@ -1237,12 +1230,13 @@  static int rcar_drif_parse_subdevs(struct rcar_drif_sdr *sdr)
 		return -EINVAL;
 	}
 
-	sdr->ep.asd.match.fwnode = fwnode;
-	sdr->ep.asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
-	ret = v4l2_async_notifier_add_subdev(notifier, &sdr->ep.asd);
+	asd = v4l2_async_notifier_add_fwnode_subdev(notifier, fwnode,
+						    sizeof(*asd));
 	fwnode_handle_put(fwnode);
+	if (IS_ERR(asd))
+		return PTR_ERR(asd);
 
-	return ret;
+	return 0;
 }
 
 /* Check if the given device is the primary bond */