ALSA: usb-audio: Fix potential zero-division at parsing FU

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: 23caaf19b1 ("ALSA: usb-mixer: Add support for Audio Class v2.0")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2017-11-21 17:07:43 +01:00
parent f658f17b5e
commit 8428a8ebde

View File

@ -1476,9 +1476,9 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid,
return -EINVAL;
}
csize = hdr->bControlSize;
if (!csize) {
if (csize <= 1) {
usb_audio_dbg(state->chip,
"unit %u: invalid bControlSize == 0\n",
"unit %u: invalid bControlSize <= 1\n",
unitid);
return -EINVAL;
}