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=-6.0 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 42269C43381 for ; Mon, 1 Apr 2019 17:34:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 13560208E4 for ; Mon, 1 Apr 2019 17:34:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554140098; bh=3+4ucH8Y+0nIjxpgKh4SvepUuZjMIiJnL42ae53wmB4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jPu1s93l4rPV1Mt0/LU94TzHPMjy+d48JazswzrujP+qomne31SV+dlB9xCa6i1EM GgTlnuALG207s1nAvWM0oh86HkwAGP4jEGzNNkhm9Wc08eNrmlCWfPNJMlSRIJbZxt TjicuA5x3K7fVrREydC9bNBN6Iv3M8svgrUl1A4Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387849AbfDARe4 (ORCPT ); Mon, 1 Apr 2019 13:34:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:45176 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387654AbfDARez (ORCPT ); Mon, 1 Apr 2019 13:34:55 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 88FA12070B; Mon, 1 Apr 2019 17:34:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554140095; bh=3+4ucH8Y+0nIjxpgKh4SvepUuZjMIiJnL42ae53wmB4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DzWRALs3vE3AOE6xt1ct+hISXtit5gMk07nl7dmW10k7J7/lUuG6mxso6K8VbAtnN BNCpzBd7rQ/bRSt6Uqa5CnIjDUSM/HFqjR+uyBLH4+zSfd80cS+8gcY++SaCexb+9t s0Iub4Z9siQocdK9k4GLIBSc0jUMat7pAreJSOxc= 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 4.4 104/131] ALSA: rawmidi: Fix potential Spectre v1 vulnerability Date: Mon, 1 Apr 2019 19:02:54 +0200 Message-Id: <20190401170100.542265877@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190401170051.645954551@linuxfoundation.org> References: <20190401170051.645954551@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 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gustavo A. R. Silva commit 2b1d9c8f87235f593826b9cf46ec10247741fff9 upstream. info->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/rawmidi.c:604 __snd_rawmidi_info_select() warn: potential spectre issue 'rmidi->streams' [r] (local cap) Fix this by sanitizing info->stream before using it to index rmidi->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://lore.kernel.org/lkml/20180423164740.GY17484@dhcp22.suse.cz/ Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/core/rawmidi.c | 2 ++ 1 file changed, 2 insertions(+) --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -591,6 +592,7 @@ static int __snd_rawmidi_info_select(str return -ENXIO; if (info->stream < 0 || info->stream > 1) return -EINVAL; + info->stream = array_index_nospec(info->stream, 2); pstr = &rmidi->streams[info->stream]; if (pstr->substream_count == 0) return -ENOENT;