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@xxxxxxxxxxxxxxxx>
> ---
> 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@xxxxxxxxxxxxxxxx>
> 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 */
>
