diff mbox series

[4/5] media: rcar-csi2: Allocate v4l2_async_subdev dynamically

Message ID 20200811205939.19550-5-laurent.pinchart+renesas@ideasonboard.com (mailing list archive)
State New
Delegated to: Kieran Bingham
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-csi2 driver embeds it in the rcar_csi2
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: 769afd212b16 ("media: rcar-csi2: add Renesas R-Car MIPI CSI-2 receiver driver")
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
 drivers/media/platform/rcar-vin/rcar-csi2.c | 24 +++++++++------------
 1 file changed, 10 insertions(+), 14 deletions(-)

Comments

Niklas Söderlund Aug. 11, 2020, 9:43 p.m. UTC | #1 
Hi Laurent,

Thanks for your work.

On 2020-08-11 23:59:38 +0300, Laurent Pinchart wrote:
> v4l2_async_notifier_add_subdev() requires the asd to be allocated
> dynamically, but the rcar-csi2 driver embeds it in the rcar_csi2
> 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.

This patch conflicts with [1] which I think is a nicer solution to the 
problem, provided 1/2 of that series is palatable for everyone :-)

1. [PATCH 2/2] rcar-csi2: Use V4L2 async helpers to create the notifier

> 
> Fixes: 769afd212b16 ("media: rcar-csi2: add Renesas R-Car MIPI CSI-2 receiver driver")
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> ---
>  drivers/media/platform/rcar-vin/rcar-csi2.c | 24 +++++++++------------
>  1 file changed, 10 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
> index c6cc4f473a07..a16c492b3143 100644
> --- a/drivers/media/platform/rcar-vin/rcar-csi2.c
> +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
> @@ -362,7 +362,6 @@ struct rcar_csi2 {
>  	struct media_pad pads[NR_OF_RCAR_CSI2_PAD];
>  
>  	struct v4l2_async_notifier notifier;
> -	struct v4l2_async_subdev asd;
>  	struct v4l2_subdev *remote;
>  
>  	struct v4l2_mbus_framefmt mf;
> @@ -811,6 +810,8 @@ static int rcsi2_parse_v4l2(struct rcar_csi2 *priv,
>  
>  static int rcsi2_parse_dt(struct rcar_csi2 *priv)
>  {
> +	struct v4l2_async_subdev *asd;
> +	struct fwnode_handle *fwnode;
>  	struct device_node *ep;
>  	struct v4l2_fwnode_endpoint v4l2_ep = { .bus_type = 0 };
>  	int ret;
> @@ -834,24 +835,19 @@ static int rcsi2_parse_dt(struct rcar_csi2 *priv)
>  		return ret;
>  	}
>  
> -	priv->asd.match.fwnode =
> -		fwnode_graph_get_remote_endpoint(of_fwnode_handle(ep));
> -	priv->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
> -
> +	fwnode = fwnode_graph_get_remote_endpoint(of_fwnode_handle(ep));
>  	of_node_put(ep);
>  
> +	dev_dbg(priv->dev, "Found '%pOF'\n", to_of_node(fwnode));
> +
>  	v4l2_async_notifier_init(&priv->notifier);
> -
> -	ret = v4l2_async_notifier_add_subdev(&priv->notifier, &priv->asd);
> -	if (ret) {
> -		fwnode_handle_put(priv->asd.match.fwnode);
> -		return ret;
> -	}
> -
>  	priv->notifier.ops = &rcar_csi2_notify_ops;
>  
> -	dev_dbg(priv->dev, "Found '%pOF'\n",
> -		to_of_node(priv->asd.match.fwnode));
> +	asd = v4l2_async_notifier_add_fwnode_subdev(&priv->notifier, fwnode,
> +						    sizeof(*asd));
> +	fwnode_handle_put(fwnode);
> +	if (IS_ERR(asd))
> +		return PTR_ERR(asd);
>  
>  	ret = v4l2_async_subdev_notifier_register(&priv->subdev,
>  						  &priv->notifier);
> -- 
> Regards,
> 
> Laurent Pinchart
>
Laurent Pinchart Aug. 11, 2020, 10:14 p.m. UTC | #2 
Hi Niklas,

On Tue, Aug 11, 2020 at 11:43:24PM +0200, Niklas Söderlund wrote:
> On 2020-08-11 23:59:38 +0300, Laurent Pinchart wrote:
> > v4l2_async_notifier_add_subdev() requires the asd to be allocated
> > dynamically, but the rcar-csi2 driver embeds it in the rcar_csi2
> > 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.
> 
> This patch conflicts with [1] which I think is a nicer solution to the 
> problem, provided 1/2 of that series is palatable for everyone :-)
> 
> 1. [PATCH 2/2] rcar-csi2: Use V4L2 async helpers to create the notifier

That looks better to me too.

> > Fixes: 769afd212b16 ("media: rcar-csi2: add Renesas R-Car MIPI CSI-2 receiver driver")
> > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> > ---
> >  drivers/media/platform/rcar-vin/rcar-csi2.c | 24 +++++++++------------
> >  1 file changed, 10 insertions(+), 14 deletions(-)
> > 
> > diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
> > index c6cc4f473a07..a16c492b3143 100644
> > --- a/drivers/media/platform/rcar-vin/rcar-csi2.c
> > +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
> > @@ -362,7 +362,6 @@ struct rcar_csi2 {
> >  	struct media_pad pads[NR_OF_RCAR_CSI2_PAD];
> >  
> >  	struct v4l2_async_notifier notifier;
> > -	struct v4l2_async_subdev asd;
> >  	struct v4l2_subdev *remote;
> >  
> >  	struct v4l2_mbus_framefmt mf;
> > @@ -811,6 +810,8 @@ static int rcsi2_parse_v4l2(struct rcar_csi2 *priv,
> >  
> >  static int rcsi2_parse_dt(struct rcar_csi2 *priv)
> >  {
> > +	struct v4l2_async_subdev *asd;
> > +	struct fwnode_handle *fwnode;
> >  	struct device_node *ep;
> >  	struct v4l2_fwnode_endpoint v4l2_ep = { .bus_type = 0 };
> >  	int ret;
> > @@ -834,24 +835,19 @@ static int rcsi2_parse_dt(struct rcar_csi2 *priv)
> >  		return ret;
> >  	}
> >  
> > -	priv->asd.match.fwnode =
> > -		fwnode_graph_get_remote_endpoint(of_fwnode_handle(ep));
> > -	priv->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
> > -
> > +	fwnode = fwnode_graph_get_remote_endpoint(of_fwnode_handle(ep));
> >  	of_node_put(ep);
> >  
> > +	dev_dbg(priv->dev, "Found '%pOF'\n", to_of_node(fwnode));
> > +
> >  	v4l2_async_notifier_init(&priv->notifier);
> > -
> > -	ret = v4l2_async_notifier_add_subdev(&priv->notifier, &priv->asd);
> > -	if (ret) {
> > -		fwnode_handle_put(priv->asd.match.fwnode);
> > -		return ret;
> > -	}
> > -
> >  	priv->notifier.ops = &rcar_csi2_notify_ops;
> >  
> > -	dev_dbg(priv->dev, "Found '%pOF'\n",
> > -		to_of_node(priv->asd.match.fwnode));
> > +	asd = v4l2_async_notifier_add_fwnode_subdev(&priv->notifier, fwnode,
> > +						    sizeof(*asd));
> > +	fwnode_handle_put(fwnode);
> > +	if (IS_ERR(asd))
> > +		return PTR_ERR(asd);
> >  
> >  	ret = v4l2_async_subdev_notifier_register(&priv->subdev,
> >  						  &priv->notifier);
diff mbox series

Patch

diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
index c6cc4f473a07..a16c492b3143 100644
--- a/drivers/media/platform/rcar-vin/rcar-csi2.c
+++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
@@ -362,7 +362,6 @@  struct rcar_csi2 {
 	struct media_pad pads[NR_OF_RCAR_CSI2_PAD];
 
 	struct v4l2_async_notifier notifier;
-	struct v4l2_async_subdev asd;
 	struct v4l2_subdev *remote;
 
 	struct v4l2_mbus_framefmt mf;
@@ -811,6 +810,8 @@  static int rcsi2_parse_v4l2(struct rcar_csi2 *priv,
 
 static int rcsi2_parse_dt(struct rcar_csi2 *priv)
 {
+	struct v4l2_async_subdev *asd;
+	struct fwnode_handle *fwnode;
 	struct device_node *ep;
 	struct v4l2_fwnode_endpoint v4l2_ep = { .bus_type = 0 };
 	int ret;
@@ -834,24 +835,19 @@  static int rcsi2_parse_dt(struct rcar_csi2 *priv)
 		return ret;
 	}
 
-	priv->asd.match.fwnode =
-		fwnode_graph_get_remote_endpoint(of_fwnode_handle(ep));
-	priv->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
-
+	fwnode = fwnode_graph_get_remote_endpoint(of_fwnode_handle(ep));
 	of_node_put(ep);
 
+	dev_dbg(priv->dev, "Found '%pOF'\n", to_of_node(fwnode));
+
 	v4l2_async_notifier_init(&priv->notifier);
-
-	ret = v4l2_async_notifier_add_subdev(&priv->notifier, &priv->asd);
-	if (ret) {
-		fwnode_handle_put(priv->asd.match.fwnode);
-		return ret;
-	}
-
 	priv->notifier.ops = &rcar_csi2_notify_ops;
 
-	dev_dbg(priv->dev, "Found '%pOF'\n",
-		to_of_node(priv->asd.match.fwnode));
+	asd = v4l2_async_notifier_add_fwnode_subdev(&priv->notifier, fwnode,
+						    sizeof(*asd));
+	fwnode_handle_put(fwnode);
+	if (IS_ERR(asd))
+		return PTR_ERR(asd);
 
 	ret = v4l2_async_subdev_notifier_register(&priv->subdev,
 						  &priv->notifier);