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* [PATCH] ALSA: ac97: Fix possible error value of *rac97
@ 2023-08-23  2:52 Su Hui
  2023-08-23 17:20 ` Christophe JAILLET
  0 siblings, 1 reply; 3+ messages in thread
From: Su Hui @ 2023-08-23  2:52 UTC (permalink / raw)
  To: perex, tiwai, Christophe JAILLET
  Cc: suhui, arnd, robert.jarzmik, yangyingliang, maciej.szmigiero,
	alsa-devel, linux-kernel, kernel-janitors

Before committing 79597c8bf64c, *rac97 always be NULL if there is
an error. When error happens, make sure *rac97 is NULL is safer.

For examble, in snd_vortex_mixer():
	err = snd_ac97_mixer(pbus, &ac97, &vortex->codec);
	vortex->isquad = ((vortex->codec == NULL) ?
		0 : (vortex->codec->ext_id&0x80));
If error happened but vortex->codec isn't NULL, this may cause some
problems.

Move the judgement order to be clearer and better.

Fixes: 79597c8bf64c ("ALSA: ac97: Fix possible NULL dereference in snd_ac97_mixer")
Suggested-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Su Hui <suhui@nfschina.com>
---
 sound/pci/ac97/ac97_codec.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/sound/pci/ac97/ac97_codec.c b/sound/pci/ac97/ac97_codec.c
index 80a65b8ad7b9..25f93e56cfc7 100644
--- a/sound/pci/ac97/ac97_codec.c
+++ b/sound/pci/ac97/ac97_codec.c
@@ -2069,10 +2069,9 @@ int snd_ac97_mixer(struct snd_ac97_bus *bus, struct snd_ac97_template *template,
 		.dev_disconnect =	snd_ac97_dev_disconnect,
 	};
 
-	if (!rac97)
-		return -EINVAL;
-	if (snd_BUG_ON(!bus || !template))
+	if (snd_BUG_ON(!bus || !template || !rac97))
 		return -EINVAL;
+	*rac97 = NULL;
 	if (snd_BUG_ON(template->num >= 4))
 		return -EINVAL;
 	if (bus->codec[template->num])
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] ALSA: ac97: Fix possible error value of *rac97
  2023-08-23  2:52 [PATCH] ALSA: ac97: Fix possible error value of *rac97 Su Hui
@ 2023-08-23 17:20 ` Christophe JAILLET
  2023-08-24  8:02   ` Takashi Iwai
  0 siblings, 1 reply; 3+ messages in thread
From: Christophe JAILLET @ 2023-08-23 17:20 UTC (permalink / raw)
  To: Su Hui, perex, tiwai
  Cc: arnd, robert.jarzmik, yangyingliang, maciej.szmigiero, alsa-devel,
	linux-kernel, kernel-janitors

Le 23/08/2023 à 04:52, Su Hui a écrit :
> Before committing 79597c8bf64c, *rac97 always be NULL if there is
> an error. When error happens, make sure *rac97 is NULL is safer.
> 
> For examble, in snd_vortex_mixer():
> 	err = snd_ac97_mixer(pbus, &ac97, &vortex->codec);
> 	vortex->isquad = ((vortex->codec == NULL) ?
> 		0 : (vortex->codec->ext_id&0x80));
> If error happened but vortex->codec isn't NULL, this may cause some
> problems.
> 
> Move the judgement order to be clearer and better.
> 
> Fixes: 79597c8bf64c ("ALSA: ac97: Fix possible NULL dereference in snd_ac97_mixer")
> Suggested-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> Signed-off-by: Su Hui <suhui@nfschina.com>
> ---
>   sound/pci/ac97/ac97_codec.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/sound/pci/ac97/ac97_codec.c b/sound/pci/ac97/ac97_codec.c
> index 80a65b8ad7b9..25f93e56cfc7 100644
> --- a/sound/pci/ac97/ac97_codec.c
> +++ b/sound/pci/ac97/ac97_codec.c
> @@ -2069,10 +2069,9 @@ int snd_ac97_mixer(struct snd_ac97_bus *bus, struct snd_ac97_template *template,
>   		.dev_disconnect =	snd_ac97_dev_disconnect,
>   	};
>   
> -	if (!rac97)
> -		return -EINVAL;
> -	if (snd_BUG_ON(!bus || !template))
> +	if (snd_BUG_ON(!bus || !template || !rac97))
>   		return -EINVAL;
> +	*rac97 = NULL;
>   	if (snd_BUG_ON(template->num >= 4))
>   		return -EINVAL;
>   	if (bus->codec[template->num])

FWIW,

Acked-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

CJ

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] ALSA: ac97: Fix possible error value of *rac97
  2023-08-23 17:20 ` Christophe JAILLET
@ 2023-08-24  8:02   ` Takashi Iwai
  0 siblings, 0 replies; 3+ messages in thread
From: Takashi Iwai @ 2023-08-24  8:02 UTC (permalink / raw)
  To: Su Hui
  Cc: Christophe JAILLET, perex, tiwai, arnd, robert.jarzmik,
	yangyingliang, maciej.szmigiero, alsa-devel, linux-kernel,
	kernel-janitors

On Wed, 23 Aug 2023 19:20:49 +0200,
Christophe JAILLET wrote:
> 
> Le 23/08/2023 à 04:52, Su Hui a écrit :
> > Before committing 79597c8bf64c, *rac97 always be NULL if there is
> > an error. When error happens, make sure *rac97 is NULL is safer.
> > 
> > For examble, in snd_vortex_mixer():
> > 	err = snd_ac97_mixer(pbus, &ac97, &vortex->codec);
> > 	vortex->isquad = ((vortex->codec == NULL) ?
> > 		0 : (vortex->codec->ext_id&0x80));
> > If error happened but vortex->codec isn't NULL, this may cause some
> > problems.
> > 
> > Move the judgement order to be clearer and better.
> > 
> > Fixes: 79597c8bf64c ("ALSA: ac97: Fix possible NULL dereference in snd_ac97_mixer")
> > Suggested-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> > Signed-off-by: Su Hui <suhui@nfschina.com>
> > ---
> >   sound/pci/ac97/ac97_codec.c | 5 ++---
> >   1 file changed, 2 insertions(+), 3 deletions(-)
> > 
> > diff --git a/sound/pci/ac97/ac97_codec.c b/sound/pci/ac97/ac97_codec.c
> > index 80a65b8ad7b9..25f93e56cfc7 100644
> > --- a/sound/pci/ac97/ac97_codec.c
> > +++ b/sound/pci/ac97/ac97_codec.c
> > @@ -2069,10 +2069,9 @@ int snd_ac97_mixer(struct snd_ac97_bus *bus, struct snd_ac97_template *template,
> >   		.dev_disconnect =	snd_ac97_dev_disconnect,
> >   	};
> >   -	if (!rac97)
> > -		return -EINVAL;
> > -	if (snd_BUG_ON(!bus || !template))
> > +	if (snd_BUG_ON(!bus || !template || !rac97))
> >   		return -EINVAL;
> > +	*rac97 = NULL;
> >   	if (snd_BUG_ON(template->num >= 4))
> >   		return -EINVAL;
> >   	if (bus->codec[template->num])
> 
> FWIW,
> 
> Acked-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Applied now, thanks.


Takashi

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2023-08-24  8:05 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2023-08-23  2:52 [PATCH] ALSA: ac97: Fix possible error value of *rac97 Su Hui
2023-08-23 17:20 ` Christophe JAILLET
2023-08-24  8:02   ` Takashi Iwai

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