From 8428a8ebde2db1e988e41a58497a28beb7ce1705 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 21 Nov 2017 17:07:43 +0100
Subject: [PATCH] ALSA: usb-audio: Fix potential zero-division at parsing FU
Git-commit: 8428a8ebde2db1e988e41a58497a28beb7ce1705
Patch-mainline: v4.15-rc1
References: bsc#1121278
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")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/usb/mixer.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 61b348383de8..0537c6322990 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) {
+ if (csize <= 1) {
usb_audio_dbg(state->chip,
- "unit %u: invalid bControlSize == 0\n",
+ "unit %u: invalid bControlSize <= 1\n",
unitid);
return -EINVAL;
}
--
2.20.1