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,URIBL_BLOCKED,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 CC5C4C43387 for ; Mon, 7 Jan 2019 12:40:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C7452183F for ; Mon, 7 Jan 2019 12:40:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546864852; bh=gBpEHLnwHAu8DP7iKtRnEkFc6++KR2UKXm3jxIsOG6g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PCvxGyPkAWM25QVHIgw1LYtcw/+iN1O/ZQ2SeNfuvs3pDVcbQxqqV6MUUhktPj/+y UyIkeDvg3Zt5usHYdBbaC5k8oHvO/FV3tw3FUlOXIjfERyGCIcvYkodvU9KzdDLQ9J Ue6b7+r8hqFo1yV+mNyJvV3bwBErWAG4sk8UlpQo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728049AbfAGMkv (ORCPT ); Mon, 7 Jan 2019 07:40:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:47134 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727270AbfAGMeg (ORCPT ); Mon, 7 Jan 2019 07:34:36 -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 5C16321855; Mon, 7 Jan 2019 12:34:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546864475; bh=gBpEHLnwHAu8DP7iKtRnEkFc6++KR2UKXm3jxIsOG6g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eVyPXteUzXoCGdjtqVl+7gfchExfjDY89RDikbnQUVkZDXbs0r/VcYKtx+N6pD8AZ 4L1rId0/KPU5abK1K4yU+ZSN0nDssBwWccRxLd0SNAVsDZDLwS90f5a1d8p3h3kwsj zFif68ctBB1W39EUo1gMMgMDtasKXJWCfBXcQtYQ= 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 4.20 024/145] ALSA: emux: Fix potential Spectre v1 vulnerabilities Date: Mon, 7 Jan 2019 13:31:01 +0100 Message-Id: <20190107104440.476724256@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190107104437.308206189@linuxfoundation.org> References: <20190107104437.308206189@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 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gustavo A. R. Silva commit 4aea96f4237cea0c51a8bc87c0db31f0f932f1f0 upstream. info.mode and info.port are indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. These issues were detected with the help of Smatch: sound/synth/emux/emux_hwdep.c:72 snd_emux_hwdep_misc_mode() warn: potential spectre issue 'emu->portptrs[i]->ctrls' [w] (local cap) sound/synth/emux/emux_hwdep.c:75 snd_emux_hwdep_misc_mode() warn: potential spectre issue 'emu->portptrs' [w] (local cap) sound/synth/emux/emux_hwdep.c:75 snd_emux_hwdep_misc_mode() warn: potential spectre issue 'emu->portptrs[info.port]->ctrls' [w] (local cap) Fix this by sanitizing both info.mode and info.port before using them to index emu->portptrs[i]->ctrls, emu->portptrs[info.port]->ctrls and emu->portptrs. 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/synth/emux/emux_hwdep.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/sound/synth/emux/emux_hwdep.c +++ b/sound/synth/emux/emux_hwdep.c @@ -22,9 +22,9 @@ #include #include #include +#include #include "emux_voice.h" - #define TMP_CLIENT_ID 0x1001 /* @@ -66,13 +66,16 @@ snd_emux_hwdep_misc_mode(struct snd_emux return -EFAULT; if (info.mode < 0 || info.mode >= EMUX_MD_END) return -EINVAL; + info.mode = array_index_nospec(info.mode, EMUX_MD_END); if (info.port < 0) { for (i = 0; i < emu->num_ports; i++) emu->portptrs[i]->ctrls[info.mode] = info.value; } else { - if (info.port < emu->num_ports) + if (info.port < emu->num_ports) { + info.port = array_index_nospec(info.port, emu->num_ports); emu->portptrs[info.port]->ctrls[info.mode] = info.value; + } } return 0; }