3.2.99-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Takashi Iwai <tiwai@xxxxxxx>
commit 8428a8ebde2db1e988e41a58497a28beb7ce1705 upstream.
parse_audio_feature_unit() contains a code dividing potentially with
zero when a malformed FU descriptor is passed. Although there is
already a sanity check, it checks only the value zero, hence it can
still lead to a zero-division when a value 1 is passed there.
Fix it by correcting the sanity check (and the error message
thereof).
Fixes: 23caaf19b11e ("ALSA: usb-mixer: Add support for Audio Class v2.0")
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
sound/usb/mixer.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -1262,9 +1262,9 @@ static int parse_audio_feature_unit(stru
return -EINVAL;
}
csize = hdr->bControlSize;
- if (!csize) {
+ if (csize <= 1) {
snd_printdd(KERN_ERR "usbaudio: unit %u: "
- "invalid bControlSize == 0\n", unitid);
+ "invalid bControlSize <= 1\n", unitid);
return -EINVAL;
}
channels = (hdr->bLength - 7) / csize - 1;