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 6D74DC10F05 for ; Mon, 1 Apr 2019 17:27:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 364DE2063F for ; Mon, 1 Apr 2019 17:27:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554139634; bh=QNXv7/8RXSvK203CoLihJBZx9tTjGwjQJ8BAGbFnupk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uEn55w+f3XehORraMGOiDbRvror7H6Bu9PckcaAGdiw1HuKWssASJ/DjU2Xo15wyV sul0+wZMud5sRyTABXaVWLxxY2M3Tv2YfdhxhL+uwoGqecCzE60wopfRm9gkMjUrxp cAvY+GcjcOHPXDvfGaSnxBHlOpNZHMaGbsiaXzTM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732644AbfDAR1M (ORCPT ); Mon, 1 Apr 2019 13:27:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:59708 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732188AbfDAR1H (ORCPT ); Mon, 1 Apr 2019 13:27:07 -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 A433A20880; Mon, 1 Apr 2019 17:27:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554139627; bh=QNXv7/8RXSvK203CoLihJBZx9tTjGwjQJ8BAGbFnupk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qYYIcBRCYDpwszv1jkmZGVXRfgvwkCNIteGyznHJMjiM9U8JAFLcTe8fqkxv8AcTn dq+yZEmFq1qVI1VCd3y6Fh1bGfE6QNc33zMqYBbk57ilQeW9XzigV1ANOlQDTKaSXh vQmV6p8y2SMk9SMdP1RvGmcVhFA2BCdAjR7w+qOA= 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 4.9 23/56] ALSA: rawmidi: Fix potential Spectre v1 vulnerability Date: Mon, 1 Apr 2019 19:02:39 +0200 Message-Id: <20190401170105.254898108@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190401170103.398401360@linuxfoundation.org> References: <20190401170103.398401360@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 4.9-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;