From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51208C54FD0 for ; Thu, 23 Apr 2020 23:07:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3648B20780 for ; Thu, 23 Apr 2020 23:07:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728852AbgDWXHX (ORCPT ); Thu, 23 Apr 2020 19:07:23 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:50056 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728505AbgDWXGv (ORCPT ); Thu, 23 Apr 2020 19:06:51 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jRkva-0004nQ-Rd; Fri, 24 Apr 2020 00:06:43 +0100 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1jRkvW-00E6wQ-BW; Fri, 24 Apr 2020 00:06:38 +0100 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, Denis Kirjanov , "Johan Hovold" , "Takashi Iwai" Date: Fri, 24 Apr 2020 00:06:49 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 182/245] ALSA: usb-audio: fix sync-ep altsetting sanity check In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.83-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit 5d1b71226dc4d44b4b65766fa9d74492f9d4587b upstream. The altsetting sanity check in set_sync_ep_implicit_fb_quirk() was checking for there to be at least one altsetting but then went on to access the second one, which may not exist. This could lead to random slab data being used to initialise the sync endpoint in snd_usb_add_endpoint(). Fixes: c75a8a7ae565 ("ALSA: snd-usb: add support for implicit feedback") Fixes: ca10a7ebdff1 ("ALSA: usb-audio: FT C400 sync playback EP to capture EP") Fixes: 5e35dc0338d8 ("ALSA: usb-audio: add implicit fb quirk for Behringer UFX1204") Fixes: 17f08b0d9aaf ("ALSA: usb-audio: add implicit fb quirk for Axe-Fx II") Fixes: 103e9625647a ("ALSA: usb-audio: simplify set_sync_ep_implicit_fb_quirk") Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20200114083953.1106-1-johan@kernel.org Signed-off-by: Takashi Iwai Signed-off-by: Ben Hutchings --- sound/usb/pcm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -368,7 +368,7 @@ static int set_sync_ep_implicit_fb_quirk add_sync_ep_from_ifnum: iface = usb_ifnum_to_if(dev, ifnum); - if (!iface || iface->num_altsetting == 0) + if (!iface || iface->num_altsetting < 2) return -EINVAL; alts = &iface->altsetting[1];