2015-11-25 12:50:38

by Corentin Labbe

[permalink] [raw]
Subject: [PATCH] ASoC: rsnd: fix a possible NULL dereference

of_match_device could return NULL, and so cause a NULL pointer
dereference later.
Even if the probability of this case is very low, fixing it made
static analyzers happy.
Solving this with of_device_get_match_data made also code simplier.

Signed-off-by: LABBE Corentin <[email protected]>
---
sound/soc/sh/rcar/core.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sound/soc/sh/rcar/core.c b/sound/soc/sh/rcar/core.c
index deed48e..54cc44c 100644
--- a/sound/soc/sh/rcar/core.c
+++ b/sound/soc/sh/rcar/core.c
@@ -1204,7 +1204,6 @@ static int rsnd_probe(struct platform_device *pdev)
struct rsnd_priv *priv;
struct device *dev = &pdev->dev;
struct rsnd_dai *rdai;
- const struct of_device_id *of_id = of_match_device(rsnd_of_match, dev);
const struct rsnd_of_data *of_data;
int (*probe_func[])(struct platform_device *pdev,
const struct rsnd_of_data *of_data,
@@ -1221,11 +1220,13 @@ static int rsnd_probe(struct platform_device *pdev)
};
int ret, i;

+ of_data = of_device_get_match_data(dev);
+ if (!of_data)
+ return 1;
info = devm_kzalloc(&pdev->dev, sizeof(struct rcar_snd_info),
GFP_KERNEL);
if (!info)
return -ENOMEM;
- of_data = of_id->data;

/*
* init priv data
--
2.4.10


2015-11-25 23:46:55

by Kuninori Morimoto

[permalink] [raw]
Subject: Re: [PATCH] ASoC: rsnd: fix a possible NULL dereference


Hi LABBE

Thank you for your patch

> of_match_device could return NULL, and so cause a NULL pointer
> dereference later.
> Even if the probability of this case is very low, fixing it made
> static analyzers happy.
> Solving this with of_device_get_match_data made also code simplier.
>
> Signed-off-by: LABBE Corentin <[email protected]>
> ---
> sound/soc/sh/rcar/core.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/sound/soc/sh/rcar/core.c b/sound/soc/sh/rcar/core.c
> index deed48e..54cc44c 100644
> --- a/sound/soc/sh/rcar/core.c
> +++ b/sound/soc/sh/rcar/core.c
> @@ -1204,7 +1204,6 @@ static int rsnd_probe(struct platform_device *pdev)
> struct rsnd_priv *priv;
> struct device *dev = &pdev->dev;
> struct rsnd_dai *rdai;
> - const struct of_device_id *of_id = of_match_device(rsnd_of_match, dev);
> const struct rsnd_of_data *of_data;
> int (*probe_func[])(struct platform_device *pdev,
> const struct rsnd_of_data *of_data,
> @@ -1221,11 +1220,13 @@ static int rsnd_probe(struct platform_device *pdev)
> };
> int ret, i;
>
> + of_data = of_device_get_match_data(dev);
> + if (!of_data)
> + return 1;

return 1 ?
You want to use -EINVAL ?

2015-11-26 07:17:24

by Corentin Labbe

[permalink] [raw]
Subject: Re: [PATCH] ASoC: rsnd: fix a possible NULL dereference

On Wed, Nov 25, 2015 at 11:46:45PM +0000, Kuninori Morimoto wrote:
>
> Hi LABBE
>
> Thank you for your patch
>
> > of_match_device could return NULL, and so cause a NULL pointer
> > dereference later.
> > Even if the probability of this case is very low, fixing it made
> > static analyzers happy.
> > Solving this with of_device_get_match_data made also code simplier.
> >
> > Signed-off-by: LABBE Corentin <[email protected]>
> > ---
> > sound/soc/sh/rcar/core.c | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/sound/soc/sh/rcar/core.c b/sound/soc/sh/rcar/core.c
> > index deed48e..54cc44c 100644
> > --- a/sound/soc/sh/rcar/core.c
> > +++ b/sound/soc/sh/rcar/core.c
> > @@ -1204,7 +1204,6 @@ static int rsnd_probe(struct platform_device *pdev)
> > struct rsnd_priv *priv;
> > struct device *dev = &pdev->dev;
> > struct rsnd_dai *rdai;
> > - const struct of_device_id *of_id = of_match_device(rsnd_of_match, dev);
> > const struct rsnd_of_data *of_data;
> > int (*probe_func[])(struct platform_device *pdev,
> > const struct rsnd_of_data *of_data,
> > @@ -1221,11 +1220,13 @@ static int rsnd_probe(struct platform_device *pdev)
> > };
> > int ret, i;
> >
> > + of_data = of_device_get_match_data(dev);
> > + if (!of_data)
> > + return 1;
>
> return 1 ?
> You want to use -EINVAL ?
>

I do that Uwe Kleine-K?nig said to me to do in others thread:
https://lkml.org/lkml/2015/11/12/70 and https://lkml.org/lkml/2015/11/16/211

Regards

2015-11-30 16:39:07

by Mark Brown

[permalink] [raw]
Subject: Re: [PATCH] ASoC: rsnd: fix a possible NULL dereference

On Thu, Nov 26, 2015 at 08:17:15AM +0100, LABBE Corentin wrote:
> On Wed, Nov 25, 2015 at 11:46:45PM +0000, Kuninori Morimoto wrote:

> > > + of_data = of_device_get_match_data(dev);
> > > + if (!of_data)
> > > + return 1;

> > return 1 ?
> > You want to use -EINVAL ?

> I do that Uwe Kleine-K?nig said to me to do in others thread:
> https://lkml.org/lkml/2015/11/12/70 and https://lkml.org/lkml/2015/11/16/211

What error code to return is going to depend on the context - you need
to look at what the caller is expecting and how it will handle the value
returned.


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