diff mbox series

[v2] media: i2c: max9286: Fix async subdev size

Message ID 20200915123914.22807-1-jacopo+renesas@jmondi.org
State New
Headers show
Series [v2] media: i2c: max9286: Fix async subdev size | expand

Commit Message

Jacopo Mondi Sept. 15, 2020, 12:39 p.m. UTC
Since
commit 86d37bf31af6 ("media: i2c: max9286: Allocate v4l2_async_subdev dynamically")
the async subdevice registered to the max9286 notifier is dynamically
allocated by the v4l2 framework by using the
v4l2_async_notifier_add_fwnode_subdev() function. In order to allocate
enough space for max9286_asd structure that encloses the async subdevice
paired with a pointer to the corresponding source, pass to the framework
the size of the whole structure in place of the one of the enclosed async
subdev.

Fixes: 86d37bf31af6 ("media: i2c: max9286: Allocate v4l2_async_subdev dynamically")
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 drivers/media/i2c/max9286.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--
2.28.0

Comments

Kieran Bingham Sept. 16, 2020, 11 a.m. UTC | #1
Hi Jacopo,

On 15/09/2020 13:39, Jacopo Mondi wrote:
> Since

Does 'Since' really need it's own line ;-)

> commit 86d37bf31af6 ("media: i2c: max9286: Allocate v4l2_async_subdev dynamically")
> the async subdevice registered to the max9286 notifier is dynamically
> allocated by the v4l2 framework by using the
> v4l2_async_notifier_add_fwnode_subdev() function. In order to allocate

A newline before 'In order to' would be nice to split 'what happened'
from 'what is going to happen'. Oh, in fact it doesn't describe what
happened though...

> enough space for max9286_asd structure that encloses the async subdevice

for "the" max9286_asd...


> paired with a pointer to the corresponding source, pass to the framework
> the size of the whole structure in place of the one of the enclosed async
> subdev.

That's quite hard to parse though, and I don't think describing the
contents of max9286_asd really matters here?

How about:

Since commit 86d37bf31af6 ("media: i2c: max9286: Allocate
v4l2_async_subdev dynamically") the async subdevice registered to the
max9286 notifier is dynamically allocated by the v4l2 framework by using
the v4l2_async_notifier_add_fwnode_subdev() function, but provides an
incorrect size, potentially leading to incorrect memory accesses.

Allocate enough space for the driver specific max9286_asd structure
(which contains the async subdevice) by passing the size of the correct
structure.

> Fixes: 86d37bf31af6 ("media: i2c: max9286: Allocate v4l2_async_subdev dynamically")
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

The code is fine though, so with any commit message updates you deem
necessary:

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

> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> ---
>  drivers/media/i2c/max9286.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> index c82c1493e099..6852448284ea 100644
> --- a/drivers/media/i2c/max9286.c
> +++ b/drivers/media/i2c/max9286.c
> @@ -577,10 +577,11 @@ 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;
> +		struct max9286_asd *masd;
> 
>  		asd = v4l2_async_notifier_add_fwnode_subdev(&priv->notifier,
>  							    source->fwnode,
> -							    sizeof(*asd));
> +							    sizeof(*masd));
>  		if (IS_ERR(asd)) {
>  			dev_err(dev, "Failed to add subdev for source %u: %ld",
>  				i, PTR_ERR(asd));
> @@ -588,7 +589,8 @@ static int max9286_v4l2_notifier_register(struct max9286_priv *priv)
>  			return PTR_ERR(asd);
>  		}
> 
> -		to_max9286_asd(asd)->source = source;
> +		masd = to_max9286_asd(asd);
> +		masd->source = source;
>  	}
> 
>  	priv->notifier.ops = &max9286_notify_ops;
> --
> 2.28.0
>
Jacopo Mondi Sept. 16, 2020, 11:18 a.m. UTC | #2
Hi Kieran,

On Wed, Sep 16, 2020 at 12:00:53PM +0100, Kieran Bingham wrote:
> Hi Jacopo,
>
> On 15/09/2020 13:39, Jacopo Mondi wrote:
> > Since
>
> Does 'Since' really need it's own line ;-)
>

If you don't want to break the following one (which I understand is
better on a single line) yes

> > commit 86d37bf31af6 ("media: i2c: max9286: Allocate v4l2_async_subdev dynamically")
> > the async subdevice registered to the max9286 notifier is dynamically
> > allocated by the v4l2 framework by using the
> > v4l2_async_notifier_add_fwnode_subdev() function. In order to allocate
>
> A newline before 'In order to' would be nice to split 'what happened'
> from 'what is going to happen'. Oh, in fact it doesn't describe what
> happened though...
>
> > enough space for max9286_asd structure that encloses the async subdevice
>
> for "the" max9286_asd...
>
>
> > paired with a pointer to the corresponding source, pass to the framework
> > the size of the whole structure in place of the one of the enclosed async
> > subdev.
>
> That's quite hard to parse though, and I don't think describing the
> contents of max9286_asd really matters here?
>
> How about:
>
> Since commit 86d37bf31af6 ("media: i2c: max9286: Allocate
> v4l2_async_subdev dynamically") the async subdevice registered to the
> max9286 notifier is dynamically allocated by the v4l2 framework by using
> the v4l2_async_notifier_add_fwnode_subdev() function, but provides an
> incorrect size, potentially leading to incorrect memory accesses.
>
> Allocate enough space for the driver specific max9286_asd structure
> (which contains the async subdevice) by passing the size of the correct
> structure.
>
> > Fixes: 86d37bf31af6 ("media: i2c: max9286: Allocate v4l2_async_subdev dynamically")
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>
> The code is fine though, so with any commit message updates you deem
> necessary:
>
> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

Ok, better than mine, I'll take it in.

Thanks.
    j

>
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > ---
> >  drivers/media/i2c/max9286.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> > index c82c1493e099..6852448284ea 100644
> > --- a/drivers/media/i2c/max9286.c
> > +++ b/drivers/media/i2c/max9286.c
> > @@ -577,10 +577,11 @@ 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;
> > +		struct max9286_asd *masd;
> >
> >  		asd = v4l2_async_notifier_add_fwnode_subdev(&priv->notifier,
> >  							    source->fwnode,
> > -							    sizeof(*asd));
> > +							    sizeof(*masd));
> >  		if (IS_ERR(asd)) {
> >  			dev_err(dev, "Failed to add subdev for source %u: %ld",
> >  				i, PTR_ERR(asd));
> > @@ -588,7 +589,8 @@ static int max9286_v4l2_notifier_register(struct max9286_priv *priv)
> >  			return PTR_ERR(asd);
> >  		}
> >
> > -		to_max9286_asd(asd)->source = source;
> > +		masd = to_max9286_asd(asd);
> > +		masd->source = source;
> >  	}
> >
> >  	priv->notifier.ops = &max9286_notify_ops;
> > --
> > 2.28.0
> >
>
diff mbox series

Patch

diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
index c82c1493e099..6852448284ea 100644
--- a/drivers/media/i2c/max9286.c
+++ b/drivers/media/i2c/max9286.c
@@ -577,10 +577,11 @@  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;
+		struct max9286_asd *masd;

 		asd = v4l2_async_notifier_add_fwnode_subdev(&priv->notifier,
 							    source->fwnode,
-							    sizeof(*asd));
+							    sizeof(*masd));
 		if (IS_ERR(asd)) {
 			dev_err(dev, "Failed to add subdev for source %u: %ld",
 				i, PTR_ERR(asd));
@@ -588,7 +589,8 @@  static int max9286_v4l2_notifier_register(struct max9286_priv *priv)
 			return PTR_ERR(asd);
 		}

-		to_max9286_asd(asd)->source = source;
+		masd = to_max9286_asd(asd);
+		masd->source = source;
 	}

 	priv->notifier.ops = &max9286_notify_ops;