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