Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754620AbcDZXVF (ORCPT ); Tue, 26 Apr 2016 19:21:05 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:40732 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754309AbcDZXVD (ORCPT ); Tue, 26 Apr 2016 19:21:03 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Takashi Iwai" Date: Wed, 27 Apr 2016 01:02:24 +0200 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 035/115] ALSA: usb-audio: Fix NULL dereference in create_fixed_stream_quirk() In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8426:ae4:c500:9cba:69ae:962d:6167 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 Content-Length: 1213 Lines: 40 3.2.80-rc1 review patch. If anyone has any objections, please let me know. ------------------ 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 [bwh: Backported to 3.2: - There's no altsd variable - Adjust context] Signed-off-by: Ben Hutchings --- sound/usb/quirks.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -165,6 +165,12 @@ static int create_fixed_stream_quirk(str return -EINVAL; } alts = &iface->altsetting[fp->altset_idx]; + if (get_iface_desc(alts)->bNumEndpoints < 1) { + kfree(fp); + kfree(rate_table); + return -EINVAL; + } + fp->datainterval = snd_usb_parse_datainterval(chip, alts); fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize); usb_set_interface(chip->dev, fp->iface, 0);