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 EF716C43381 for ; Mon, 1 Apr 2019 17:15:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B39812171F for ; Mon, 1 Apr 2019 17:15:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554138919; bh=+nXd50clnepF6RQyo8ZArmXVXGCmvgi0rEAHokRAIj0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RAMLW5Wwff2SfQTlUGglpOuQ5qGaoUKx1yy00XXF/LXFiLPhxvALrRxuUVXQyEPVe No3yR0dbdgoNS0XMNbIMIn+MowoYuoE52tkXK5RzbGS7dP2nofokNjtCa4Yh4hP20p yND1QK9gXojHEl03YWawqKkqUAqrUAXRAavaRyBA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730882AbfDARPS (ORCPT ); Mon, 1 Apr 2019 13:15:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:39272 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730501AbfDARPQ (ORCPT ); Mon, 1 Apr 2019 13:15:16 -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 B05AD206C0; Mon, 1 Apr 2019 17:15:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554138915; bh=+nXd50clnepF6RQyo8ZArmXVXGCmvgi0rEAHokRAIj0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=al+fc/MhMqstizbGG990HkUXWfKUePq39rKGRfPFDtz4tidFFaCkv74+/R8QH5Osv YbsVqUamaD2z3GNNefJdmEUJ3gA4aGm73+691qF6wFeW8dWnY1gb26Y8SoA8v90Mmz sQALv/lJ8+7WpuNxHBg2VkyLrzR7iAZbueHzCiRA= 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 4.19 058/134] ALSA: seq: oss: Fix Spectre v1 vulnerability Date: Mon, 1 Apr 2019 19:01:34 +0200 Message-Id: <20190401170050.044388578@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190401170044.243719205@linuxfoundation.org> References: <20190401170044.243719205@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 c709f14f0616482b67f9fbcb965e1493a03ff30b upstream. dev 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/seq/oss/seq_oss_synth.c:626 snd_seq_oss_synth_make_info() warn: potential spectre issue 'dp->synths' [w] (local cap) Fix this by sanitizing dev before using it to index dp->synths. 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/seq/oss/seq_oss_synth.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/sound/core/seq/oss/seq_oss_synth.c +++ b/sound/core/seq/oss/seq_oss_synth.c @@ -617,13 +617,14 @@ int snd_seq_oss_synth_make_info(struct seq_oss_devinfo *dp, int dev, struct synth_info *inf) { struct seq_oss_synth *rec; + struct seq_oss_synthinfo *info = get_synthinfo_nospec(dp, dev); - if (dev < 0 || dev >= dp->max_synthdev) + if (!info) return -ENXIO; - if (dp->synths[dev].is_midi) { + if (info->is_midi) { struct midi_info minf; - snd_seq_oss_midi_make_info(dp, dp->synths[dev].midi_mapped, &minf); + snd_seq_oss_midi_make_info(dp, info->midi_mapped, &minf); inf->synth_type = SYNTH_TYPE_MIDI; inf->synth_subtype = 0; inf->nr_voices = 16;