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=unavailable 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 D6DA8C43387 for ; Mon, 7 Jan 2019 13:16:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A71CC2089F for ; Mon, 7 Jan 2019 13:16:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546866960; bh=6Ae/7jO+QHtcjTwwTb99mBZ/QN/wMf8NeU9mxsTyLIs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DnMDGz77GVbjNQUI8NJxd8GknKlan6MX4aYG0M3yyYkk4v6NzgkvXW5b/jI4jil43 ByoQ2IfE/IuPHQs6u3bVRsXNQdm66GOY4fEk8Ijt1Cg6ywo9O7Jx5lUz3ttPuVBxrJ wta/wuaSP39qAFnzwfTKZAXer2qSsqchpBFe/9dw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730595AbfAGNBV (ORCPT ); Mon, 7 Jan 2019 08:01:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:48826 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730577AbfAGNBV (ORCPT ); Mon, 7 Jan 2019 08:01:21 -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 BD3D021736; Mon, 7 Jan 2019 13:01:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546866080; bh=6Ae/7jO+QHtcjTwwTb99mBZ/QN/wMf8NeU9mxsTyLIs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EHHvRWzWcj1W282nu9Ua8jw6CkZGBToN+LUdeaWwIze4jHmxnyq3xiHcOrSWQM5W7 OECP4sryt6AsHev36lkrjj1Dr6TcaJblEZ+dO3fEO3Xcm8SvijXmG4DtAh+KhzIhH4 8YMSCIWWSSGBEcGI+AB37QPvWMdIaGt7ildo8kx4= 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 4.14 038/101] ALSA: rme9652: Fix potential Spectre v1 vulnerability Date: Mon, 7 Jan 2019 13:32:26 +0100 Message-Id: <20190107105334.991118836@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190107105330.372621917@linuxfoundation.org> References: <20190107105330.372621917@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: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gustavo A. R. Silva commit 0b84304ef5da92add8dc75a1b07879c5374cdb05 upstream. info->channel 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/rme9652/hdsp.c:4100 snd_hdsp_channel_info() warn: potential spectre issue 'hdsp->channel_map' [r] (local cap) Fix this by sanitizing info->channel before using it to index hdsp->channel_map 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]. Also, notice that I refactored the code a bit in order to get rid of the following checkpatch warning: ERROR: do not use assignment in if condition FILE: sound/pci/rme9652/hdsp.c:4103: if ((mapped_channel = hdsp->channel_map[info->channel]) < 0) [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/pci/rme9652/hdsp.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/sound/pci/rme9652/hdsp.c +++ b/sound/pci/rme9652/hdsp.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -4092,15 +4093,16 @@ static int snd_hdsp_channel_info(struct struct snd_pcm_channel_info *info) { struct hdsp *hdsp = snd_pcm_substream_chip(substream); - int mapped_channel; + unsigned int channel = info->channel; - if (snd_BUG_ON(info->channel >= hdsp->max_channels)) + if (snd_BUG_ON(channel >= hdsp->max_channels)) return -EINVAL; + channel = array_index_nospec(channel, hdsp->max_channels); - if ((mapped_channel = hdsp->channel_map[info->channel]) < 0) + if (hdsp->channel_map[channel] < 0) return -EINVAL; - info->offset = mapped_channel * HDSP_CHANNEL_BUFFER_BYTES; + info->offset = hdsp->channel_map[channel] * HDSP_CHANNEL_BUFFER_BYTES; info->first = 0; info->step = 32; return 0;