From: Su Hui <suhui@nfschina.com>
Date: Thu, 15 Jun 2023 02:17:32 +0000 (+0800)
Subject: ALSA: ac97: Fix possible NULL dereference in snd_ac97_mixer
X-Git-Tag: v6.1.39~331
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d28b83252e150155b8b8c65b612c555e93c8b45f;p=platform%2Fkernel%2Flinux-starfive.git

ALSA: ac97: Fix possible NULL dereference in snd_ac97_mixer

[ 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>
---

diff --git a/sound/pci/ac97/ac97_codec.c b/sound/pci/ac97/ac97_codec.c
index ff685321f1a1..534ea7a256ec 100644
--- a/sound/pci/ac97/ac97_codec.c
+++ b/sound/pci/ac97/ac97_codec.c
@@ -2070,8 +2070,8 @@ 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))