4.14-stable review patch. If anyone has any objections, please let me know.
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From: Su Hui suhui@nfschina.com
[ Upstream commit 67de40c9df94037769967ba28c7d951afb45b7fb ]
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 Acked-by: Christophe JAILLET christophe.jaillet@wanadoo.fr Signed-off-by: Su Hui suhui@nfschina.com Link: https://lore.kernel.org/r/20230823025212.1000961-1-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 | 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 e37eab3ddc734..5095048d5cea6 100644 --- a/sound/pci/ac97/ac97_codec.c +++ b/sound/pci/ac97/ac97_codec.c @@ -2026,10 +2026,9 @@ 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])