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=-8.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 CC903C65BAF for ; Wed, 12 Dec 2018 21:36:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9268B20839 for ; Wed, 12 Dec 2018 21:36:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9268B20839 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=embeddedor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728344AbeLLVgd (ORCPT ); Wed, 12 Dec 2018 16:36:33 -0500 Received: from gateway21.websitewelcome.com ([192.185.45.133]:16981 "EHLO gateway21.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726297AbeLLVgc (ORCPT ); Wed, 12 Dec 2018 16:36:32 -0500 Received: from cm10.websitewelcome.com (cm10.websitewelcome.com [100.42.49.4]) by gateway21.websitewelcome.com (Postfix) with ESMTP id 670D3400C745D for ; Wed, 12 Dec 2018 15:36:31 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id XCBDgL67Jp9J8XCBDgzaLp; Wed, 12 Dec 2018 15:36:31 -0600 X-Authority-Reason: nr=8 Received: from [189.250.70.203] (port=58926 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1gXCBC-00447J-MA; Wed, 12 Dec 2018 15:36:30 -0600 Date: Wed, 12 Dec 2018 15:36:28 -0600 From: "Gustavo A. R. Silva" To: Jaroslav Kysela , Takashi Iwai Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] ALSA: pcm: Fix potential Spectre v1 vulnerability Message-ID: <20181212213628.GA29911@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.250.70.203 X-Source-L: No X-Exim-ID: 1gXCBC-00447J-MA X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.70.203]:58926 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 4 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org stream is indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: sound/core/pcm.c:140 snd_pcm_control_ioctl() warn: potential spectre issue 'pcm->streams' [r] (local cap) Fix this by sanitizing stream before using it to index pcm->streams Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva --- sound/core/pcm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/sound/core/pcm.c b/sound/core/pcm.c index fdb9b92fc8d6..23141003a90d 100644 --- a/sound/core/pcm.c +++ b/sound/core/pcm.c @@ -32,6 +32,8 @@ #include #include +#include + #include "pcm_local.h" MODULE_AUTHOR("Jaroslav Kysela , Abramo Bagnara "); @@ -129,6 +131,7 @@ static int snd_pcm_control_ioctl(struct snd_card *card, return -EFAULT; if (stream < 0 || stream > 1) return -EINVAL; + stream = array_index_nospec(stream, 2); if (get_user(subdevice, &info->subdevice)) return -EFAULT; mutex_lock(®ister_mutex); -- 2.17.1