[PATCH 6.4 397/800] ALSA: ac97: Fix possible NULL dereference in snd_ac97_mixer

Greg Kroah-Hartman
2023-07-16T20:12:50Z

From: Su Hui <suhui@nfschina.com>

[ Upstream commit 79597c8bf64ca99eab385115743131d260339da5 ]

smatch error:
sound/pci/ac97/ac97_codec.c:2354 snd_ac97_mixer() error:
we previously assumed 'rac97' could be null (see line 2072)

remove redundant assignment, return error if rac97 is NULL.

Fixes: da3cec35dd3c ("ALSA: Kill snd_assert() in sound/pci/*")
Signed-off-by: Su Hui <suhui@nfschina.com>
Link: https://lore.kernel.org/r/20230615021732.1972194-1-suhui@nfschina.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/pci/ac97/ac97_codec.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/pci/ac97/ac97_codec.c b/sound/pci/ac97/ac97_codec.c
index 9afc5906d662e..80a65b8ad7b9b 100644
--- a/sound/pci/ac97/ac97_codec.c
+++ b/sound/pci/ac97/ac97_codec.c
@@ -2069,8 +2069,8 @@ int snd_ac97_mixer(struct snd_ac97_bus *bus, struct snd_ac97_template *template,
.dev_disconnect = snd_ac97_dev_disconnect,
};

- if (rac97)
- *rac97 = NULL;
+ if (!rac97)
+ return -EINVAL;
if (snd_BUG_ON(!bus || !template))
return -EINVAL;
if (snd_BUG_ON(template->num >= 4))
--
2.39.2