ALSA: hda - Fix possible zero-division
Check the TLV db scale result before actually dividing in vmaster
slave init code. Also mask TLV_DB_SCALE_MUTE bit so that the right
value is obtained even if this bit is set by the codec driver.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index de1a767..33c01d5 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -2676,8 +2676,13 @@
set_fs(fs);
} else if (kctl->vd[0].access & SNDRV_CTL_ELEM_ACCESS_TLV_READ)
tlv = kctl->tlv.p;
- if (tlv && tlv[0] == SNDRV_CTL_TLVT_DB_SCALE)
- val = -tlv[2] / tlv[3];
+ if (tlv && tlv[0] == SNDRV_CTL_TLVT_DB_SCALE) {
+ int step = tlv[3];
+ step &= ~TLV_DB_SCALE_MUTE;
+ if (!step)
+ return -1;
+ val = -tlv[2] / step;
+ }
return val;
}