[PATCH] ASoC: CX20442: fix NULL pointer dereference

[PATCH] ASoC: CX20442: fix NULL pointer dereference

[Janusz Krzysztofik]

The CX20442 codec driver never provided the snd_soc_codec_driver's 
.reg_cache_default member. With the latest ASoC framework changes, it 
seems to be referred unconditionally, resulting in a NULL pointer 
dereference if missing. Provide it.

Created and tested on Amstrad Delta against linux-2.6.38-rc2

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
---
NOTE:
I'm not sure if the value choosen is Amstrad Delta specific or not.

 sound/soc/codecs/cx20442.c |    3 +++
 1 file changed, 3 insertions(+)

--- git/sound/soc/codecs/cx20442.c.orig	2011-01-31 20:09:18.000000000 +0100
+++ git/sound/soc/codecs/cx20442.c	2011-01-31 20:16:20.000000000 +0100
@@ -367,9 +367,12 @@ static int cx20442_codec_remove(struct s
 	return 0;
 }
 
+static const u8 cx20442_reg = CX20442_TELOUT | CX20442_MIC;
+
 static struct snd_soc_codec_driver cx20442_codec_dev = {
 	.probe = 	cx20442_codec_probe,
 	.remove = 	cx20442_codec_remove,
+	.reg_cache_default = &cx20442_reg,
 	.reg_cache_size = 1,
 	.reg_word_size = sizeof(u8),
 	.read = cx20442_read_reg_cache,

Re: [PATCH] ASoC: CX20442: fix NULL pointer dereference

[Janusz Krzysztofik]

On 01 February 2011 13:01:17 Janusz Krzysztofik wrote:
> The CX20442 codec driver never provided the snd_soc_codec_driver's
> .reg_cache_default member. With the latest ASoC framework changes, it
> seems to be referred unconditionally, resulting in a NULL pointer
> dereference if missing. Provide it.
> 
> Created and tested on Amstrad Delta against linux-2.6.38-rc2
> 
> Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
> ---
> NOTE:
> I'm not sure if the value choosen is Amstrad Delta specific or not.

I forgot to mention: please consider queuing this patch for the current 
rc cycle.

Thanks,
Janusz

> 
>  sound/soc/codecs/cx20442.c |    3 +++
>  1 file changed, 3 insertions(+)
> 
> --- git/sound/soc/codecs/cx20442.c.orig	2011-01-31 20:09:18.000000000 +0100
> +++ git/sound/soc/codecs/cx20442.c	2011-01-31 20:16:20.000000000 +0100
> @@ -367,9 +367,12 @@ static int cx20442_codec_remove(struct s
>  	return 0;
>  }
> 
> +static const u8 cx20442_reg = CX20442_TELOUT | CX20442_MIC;
> +
>  static struct snd_soc_codec_driver cx20442_codec_dev = {
>  	.probe = 	cx20442_codec_probe,
>  	.remove = 	cx20442_codec_remove,
> +	.reg_cache_default = &cx20442_reg,
>  	.reg_cache_size = 1,
>  	.reg_word_size = sizeof(u8),
>  	.read = cx20442_read_reg_cache,

Re: [PATCH] ASoC: CX20442: fix NULL pointer dereference

[Dimitris Papastamos]

On Tue, 2011-02-01 at 13:01 +0100, Janusz Krzysztofik wrote:
> The CX20442 codec driver never provided the snd_soc_codec_driver's 
> .reg_cache_default member. With the latest ASoC framework changes, it 
> seems to be referred unconditionally, resulting in a NULL pointer 
> dereference if missing. Provide it.

This shouldn't happen with the latest ASoC as there is support for NULL
default caches.  In particular the following code should be taking care
of the NULL pointer dereference

if (codec_drv->reg_cache_default) {
	codec->reg_def_copy = kmemdup(...);
	if (!codec->reg_def_copy) {
		ret = -ENOMEM;
		goto fail;
	}
}

If this is not what soc-core looks like for you please pull broonie's
latest development tree.

Thanks,
Dimitris

Re: [PATCH] ASoC: CX20442: fix NULL pointer dereference

[Janusz Krzysztofik]

Dnia wtorek 01 luty 2011 o 13:07:50 Dimitris Papastamos napisał(a):
> On Tue, 2011-02-01 at 13:01 +0100, Janusz Krzysztofik wrote:
> > The CX20442 codec driver never provided the snd_soc_codec_driver's
> > .reg_cache_default member. With the latest ASoC framework changes,
> > it seems to be referred unconditionally, resulting in a NULL
> > pointer dereference if missing. Provide it.
> 
> This shouldn't happen with the latest ASoC as there is support for
> NULL default caches.  In particular the following code should be
> taking care of the NULL pointer dereference
> 
> if (codec_drv->reg_cache_default) {
> 	codec->reg_def_copy = kmemdup(...);
> 	if (!codec->reg_def_copy) {
> 		ret = -ENOMEM;
> 		goto fail;
> 	}
> }
> 
> If this is not what soc-core looks like for you please pull broonie's
> latest development tree.

Fine, but your fix is sitting in Mark's 'for-2.6.39' branch, while the 
CX20442 codec driver (perhaps not only this one) has been broken for 
2.6.38.

Mark, are you going to cherry-pick Dimitris' fix to your 'for-2.6.38'?

Thanks,
Janusz
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Re: [PATCH] ASoC: CX20442: fix NULL pointer dereference

[Mark Brown]

On Tue, Feb 01, 2011 at 02:18:02PM +0100, Janusz Krzysztofik wrote:

> Mark, are you going to cherry-pick Dimitris' fix to your 'for-2.6.38'?

No.

Re: [PATCH] ASoC: CX20442: fix NULL pointer dereference

[Liam Girdwood]

On Tue, 2011-02-01 at 13:01 +0100, Janusz Krzysztofik wrote:
> The CX20442 codec driver never provided the snd_soc_codec_driver's 
> .reg_cache_default member. With the latest ASoC framework changes, it 
> seems to be referred unconditionally, resulting in a NULL pointer 
> dereference if missing. Provide it.
> 
> Created and tested on Amstrad Delta against linux-2.6.38-rc2
> 
> Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
> ---
> NOTE:
> I'm not sure if the value choosen is Amstrad Delta specific or not.
> 
>  sound/soc/codecs/cx20442.c |    3 +++
>  1 file changed, 3 insertions(+)
> 
> --- git/sound/soc/codecs/cx20442.c.orig	2011-01-31 20:09:18.000000000 +0100
> +++ git/sound/soc/codecs/cx20442.c	2011-01-31 20:16:20.000000000 +0100
> @@ -367,9 +367,12 @@ static int cx20442_codec_remove(struct s
>  	return 0;
>  }
>  
> +static const u8 cx20442_reg = CX20442_TELOUT | CX20442_MIC;
> +
>  static struct snd_soc_codec_driver cx20442_codec_dev = {
>  	.probe = 	cx20442_codec_probe,
>  	.remove = 	cx20442_codec_remove,
> +	.reg_cache_default = &cx20442_reg,
>  	.reg_cache_size = 1,
>  	.reg_word_size = sizeof(u8),
>  	.read = cx20442_read_reg_cache,
> _______________________________________________

Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
-- 
Freelance Developer, SlimLogic Ltd
ASoC and Voltage Regulator Maintainer.
http://www.slimlogic.co.uk

Re: [PATCH] ASoC: CX20442: fix NULL pointer dereference

[Mark Brown]

On Tue, Feb 01, 2011 at 01:01:17PM +0100, Janusz Krzysztofik wrote:
> The CX20442 codec driver never provided the snd_soc_codec_driver's 
> .reg_cache_default member. With the latest ASoC framework changes, it 
> seems to be referred unconditionally, resulting in a NULL pointer 
> dereference if missing. Provide it.

Applied, thanks.