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=-8.5 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 4A498C43387 for ; Tue, 18 Dec 2018 17:52:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2201C20815 for ; Tue, 18 Dec 2018 17:52:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727019AbeLRRwT (ORCPT ); Tue, 18 Dec 2018 12:52:19 -0500 Received: from gateway31.websitewelcome.com ([192.185.143.39]:49161 "EHLO gateway31.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726446AbeLRRwT (ORCPT ); Tue, 18 Dec 2018 12:52:19 -0500 Received: from cm16.websitewelcome.com (cm16.websitewelcome.com [100.42.49.19]) by gateway31.websitewelcome.com (Postfix) with ESMTP id 5C4194B798 for ; Tue, 18 Dec 2018 11:52:18 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id ZJXWgsHzk4FKpZJXWgNroP; Tue, 18 Dec 2018 11:52:18 -0600 X-Authority-Reason: nr=8 Received: from [189.250.106.44] (port=32796 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1gZJXV-002P9c-Dr; Tue, 18 Dec 2018 11:52:17 -0600 Date: Tue, 18 Dec 2018 11:52:16 -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: emu10k1: Fix potential Spectre v1 vulnerabilities Message-ID: <20181218175216.GA16070@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: 189.250.106.44 X-Source-L: No X-Exim-ID: 1gZJXV-002P9c-Dr X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.106.44]:32796 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 13 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 ipcm->substream 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/pci/emu10k1/emufx.c:1031 snd_emu10k1_ipcm_poke() warn: potential spectre issue 'emu->fx8010.pcm' [r] (local cap) sound/pci/emu10k1/emufx.c:1075 snd_emu10k1_ipcm_peek() warn: potential spectre issue 'emu->fx8010.pcm' [r] (local cap) Fix this by sanitizing ipcm->substream before using it to index emu->fx8010.pcm 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/pci/emu10k1/emufx.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/sound/pci/emu10k1/emufx.c b/sound/pci/emu10k1/emufx.c index 6ebe817801ea..1f25e6d029d8 100644 --- a/sound/pci/emu10k1/emufx.c +++ b/sound/pci/emu10k1/emufx.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include @@ -1026,6 +1027,8 @@ static int snd_emu10k1_ipcm_poke(struct snd_emu10k1 *emu, if (ipcm->substream >= EMU10K1_FX8010_PCM_COUNT) return -EINVAL; + ipcm->substream = array_index_nospec(ipcm->substream, + EMU10K1_FX8010_PCM_COUNT); if (ipcm->channels > 32) return -EINVAL; pcm = &emu->fx8010.pcm[ipcm->substream]; @@ -1072,6 +1075,8 @@ static int snd_emu10k1_ipcm_peek(struct snd_emu10k1 *emu, if (ipcm->substream >= EMU10K1_FX8010_PCM_COUNT) return -EINVAL; + ipcm->substream = array_index_nospec(ipcm->substream, + EMU10K1_FX8010_PCM_COUNT); pcm = &emu->fx8010.pcm[ipcm->substream]; mutex_lock(&emu->fx8010.lock); spin_lock_irq(&emu->reg_lock); -- 2.19.2