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 1D599C43381 for ; Mon, 1 Apr 2019 17:35:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E298B208E4 for ; Mon, 1 Apr 2019 17:35:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554140102; bh=QkXc4HHnzbKk5bLIbDOH/9Jc5CVJLYuxgDuK4mdhxUE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BgjAu092eIBQlwysutRaIgEpjt+fNjPY/tJUcKHnE+mzVLEp6+dTqTN7/qJCWR7tL vx2BPgyC/VrgAdT0pjWRkkjlmWP52+7bKuDntNXQifF0ezOHDSVXhfVHxxx/T8hKd2 PKz/sqtN3eE6YwUTRm/fraQqGSohgSkM/BOEL9W0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733024AbfDARfA (ORCPT ); Mon, 1 Apr 2019 13:35:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:45258 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387654AbfDARe6 (ORCPT ); Mon, 1 Apr 2019 13:34:58 -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 3740520880; 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=1554140097; bh=QkXc4HHnzbKk5bLIbDOH/9Jc5CVJLYuxgDuK4mdhxUE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0JFOQy3I1+ULK0ET1S+OyDNFRsSHvugu5r5ztaKLYarzXneIQZ97rZvSyrTj3mnbu b+3FcKd/FwnCf5W3rpDmcUuIDWMbjV1gqawCd17rqIBkzgyGA3vDk+PyG7m2r86Cbs H53mnPtPJitaEFqYTtX1A4pq3m1bbElszXxjwYHA= 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 4.4 105/131] ALSA: seq: oss: Fix Spectre v1 vulnerability Date: Mon, 1 Apr 2019 19:02:55 +0200 Message-Id: <20190401170100.600710965@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 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;