From: Takashi Iwai <tiwai@suse.de>
Date: Mon, 27 Nov 2017 09:59:40 +0000 (+0100)
Subject: Revert "ALSA: usb-audio: Fix potential zero-division at parsing FU"
X-Git-Tag: v4.15-rc2~31
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=3c02a6d946657e1ae0688e0d89f2dd2cfe9afba8;p=users%2Fjedix%2Flinux-maple.git

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

The commit 8428a8ebde2d ("ALSA: usb-audio: Fix potential zero-division
at parsing FU") is utterly bogus and breaks the case with csize=1
instead of fixing anything.  Just take it back again.

Reported-by: Jörg Otte <jrg.otte@gmail.com>
Fixes: 8428a8ebde2d ("ALSA: usb-audio: Fix potential zero-division at parsing FU"
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 0537c6322990..61b348383de8 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -1476,9 +1476,9 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid,
 			return -EINVAL;
 		}
 		csize = hdr->bControlSize;
-		if (csize <= 1) {
+		if (!csize) {
 			usb_audio_dbg(state->chip,
-				      "unit %u: invalid bControlSize <= 1\n",
+				      "unit %u: invalid bControlSize == 0\n",
 				      unitid);
 			return -EINVAL;
 		}