From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755142Ab3BCPBK (ORCPT ); Sun, 3 Feb 2013 10:01:10 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34623 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753650Ab3BCO6Z (ORCPT ); Sun, 3 Feb 2013 09:58:25 -0500 Message-Id: <20130203144652.800844922@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Sun, 03 Feb 2013 15:48:23 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, Clemens Ladisch , Florian Hanisch , Matthew Robbetts , Michael Beer , Daniel Mack , Takashi Iwai Subject: [ 099/128] ALSA: usb-audio: fix invalid length check for RME and other UAC 2 devices In-Reply-To: <20130203144644.035172954@decadent.org.uk> X-SA-Exim-Connect-IP: 151.216.67.5 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Clemens Ladisch commit d56268fb108c7c21e19933588ca4d94652585183 upstream. Commit 23caaf19b11e (ALSA: usb-mixer: Add support for Audio Class v2.0) forgot to adjust the length check for UAC 2.0 feature unit descriptors. This would make the code abort on encountering a feature unit without per-channel controls, and thus prevented the driver to work with any device having such a unit, such as the RME Babyface or Fireface UCX. Reported-by: Florian Hanisch Tested-by: Matthew Robbetts Tested-by: Michael Beer Cc: Daniel Mack Signed-off-by: Clemens Ladisch Signed-off-by: Takashi Iwai Signed-off-by: Ben Hutchings --- sound/usb/mixer.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index ed4d89c..e90daf8 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -1331,16 +1331,23 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void } channels = (hdr->bLength - 7) / csize - 1; bmaControls = hdr->bmaControls; + if (hdr->bLength < 7 + csize) { + snd_printk(KERN_ERR "usbaudio: unit %u: " + "invalid UAC_FEATURE_UNIT descriptor\n", + unitid); + return -EINVAL; + } } else { struct uac2_feature_unit_descriptor *ftr = _ftr; csize = 4; channels = (hdr->bLength - 6) / 4 - 1; bmaControls = ftr->bmaControls; - } - - if (hdr->bLength < 7 || !csize || hdr->bLength < 7 + csize) { - snd_printk(KERN_ERR "usbaudio: unit %u: invalid UAC_FEATURE_UNIT descriptor\n", unitid); - return -EINVAL; + if (hdr->bLength < 6 + csize) { + snd_printk(KERN_ERR "usbaudio: unit %u: " + "invalid UAC_FEATURE_UNIT descriptor\n", + unitid); + return -EINVAL; + } } /* parse the source unit */