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=-10.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT 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 F37F2C43387 for ; Mon, 7 Jan 2019 12:50:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B9C42206BB for ; Mon, 7 Jan 2019 12:50:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546865451; bh=fkzWj3BczSowI6pm6h5MABORaLYR5cdynt6UQlBJrOM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MH/iXPoVEjmXHUQpitLYuw4h0IGkW/33HrDab4h4WWhnbFiT1oaX4QISjfSp0jhTV +8nytCE1+ZtALTrT4fDPu09n6lLYzI9XUtof3EtQIBhD9T/Om4YlXTroYY0hlbwT6C Z+VwclV5tAiGHcPaD6mudd2Hput3qKY7JOuW0zoA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729164AbfAGMuv (ORCPT ); Mon, 7 Jan 2019 07:50:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:41118 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727534AbfAGMut (ORCPT ); Mon, 7 Jan 2019 07:50:49 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8D28420651; Mon, 7 Jan 2019 12:50:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546865449; bh=fkzWj3BczSowI6pm6h5MABORaLYR5cdynt6UQlBJrOM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ca8d0QT07OSKWGahhZXVaERdGWS06/lRawg4v3CjHl9jD50NFJjewebCMmecwPv1H XoxAwWtJYQVqzAkYArEoXnp+GIRPplpQk3pmetteCCExXgROBoitxSr1YlHkAc8/30 thUmL4MS30wo59GBIGCSFpijMEo/ZwMtgDC5Tlnc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Gustavo A. R. Silva" , Takashi Iwai Subject: [PATCH 4.19 062/170] ALSA: pcm: Fix potential Spectre v1 vulnerability Date: Mon, 7 Jan 2019 13:31:29 +0100 Message-Id: <20190107104500.362790119@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190107104452.953560660@linuxfoundation.org> References: <20190107104452.953560660@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gustavo A. R. Silva commit 94ffb030b6d31ec840bb811be455dd2e26a4f43e upstream. 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 Signed-off-by: Gustavo A. R. Silva Cc: stable@vger.kernel.org Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/core/pcm.c | 2 ++ 1 file changed, 2 insertions(+) --- a/sound/core/pcm.c +++ b/sound/core/pcm.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include @@ -129,6 +130,7 @@ static int snd_pcm_control_ioctl(struct 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);