Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966337AbcDLSIU (ORCPT ); Tue, 12 Apr 2016 14:08:20 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:49045 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965625AbcDLSIN (ORCPT ); Tue, 12 Apr 2016 14:08:13 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Takashi Iwai , Moritz Muehlenhoff , Luis Henriques Subject: [PATCH 3.16.y-ckt 04/17] ALSA: usb-audio: Fix NULL dereference in create_fixed_stream_quirk() Date: Tue, 12 Apr 2016 19:07:51 +0100 Message-Id: <1460484484-22395-5-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1460484484-22395-1-git-send-email-luis.henriques@canonical.com> References: <1460484484-22395-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1258 Lines: 40 3.16.7-ckt27 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Takashi Iwai commit 0f886ca12765d20124bd06291c82951fd49a33be upstream. create_fixed_stream_quirk() may cause a NULL-pointer dereference by accessing the non-existing endpoint when a USB device with a malformed USB descriptor is used. This patch avoids it simply by adding a sanity check of bNumEndpoints before the accesses. Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=971125 Signed-off-by: Takashi Iwai Cc: Moritz Muehlenhoff Signed-off-by: Luis Henriques --- sound/usb/quirks.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c index 0980405f987a..a8e3fb4c2e11 100644 --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -168,6 +168,12 @@ static int create_fixed_stream_quirk(struct snd_usb_audio *chip, } alts = &iface->altsetting[fp->altset_idx]; altsd = get_iface_desc(alts); + if (altsd->bNumEndpoints < 1) { + kfree(fp); + kfree(rate_table); + return -EINVAL; + } + fp->protocol = altsd->bInterfaceProtocol; if (fp->datainterval == 0)