From: Takashi Iwai <tiwai@suse.de>
Date: Thu, 13 Oct 2011 06:19:09 +0000 (+0200)
Subject: ALSA: usb-audio - Fix possible access over audio_feature_info[] array
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d09c06c6fc240261dde65198774b279d89c35459;p=linux-beck.git

ALSA: usb-audio - Fix possible access over audio_feature_info[] array

The audio_feature_info[] array should contain all entries for UAC2_FU_*,
but currently a few last entries are missing.  Even though, the driver
tries to probe these entries in parse_audio_feature_unit() and may
access the range over the array.  This patch fixes the bug by limiting
the loop size properly using ARRAY_SIZE() instead of a hard-coded
magic number.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index b13b7ac5bad9..60f65ace7474 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -1259,7 +1259,7 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void
 				build_feature_ctl(state, _ftr, 0, i, &iterm, unitid, 0);
 		}
 	} else { /* UAC_VERSION_2 */
-		for (i = 0; i < 30/2; i++) {
+		for (i = 0; i < ARRAY_SIZE(audio_feature_info); i++) {
 			unsigned int ch_bits = 0;
 			unsigned int ch_read_only = 0;