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=-8.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 790E3C04EB8 for ; Mon, 10 Dec 2018 19:03:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 443F520672 for ; Mon, 10 Dec 2018 19:03:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 443F520672 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=embeddedor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728966AbeLJTDh (ORCPT ); Mon, 10 Dec 2018 14:03:37 -0500 Received: from gateway23.websitewelcome.com ([192.185.49.184]:28498 "EHLO gateway23.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726024AbeLJTDg (ORCPT ); Mon, 10 Dec 2018 14:03:36 -0500 X-Greylist: delayed 1325 seconds by postgrey-1.27 at vger.kernel.org; Mon, 10 Dec 2018 14:03:36 EST Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway23.websitewelcome.com (Postfix) with ESMTP id C6EBEEB2F for ; Mon, 10 Dec 2018 12:41:30 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id WQUkgRsvvkBj6WQUkgLv27; Mon, 10 Dec 2018 12:41:30 -0600 X-Authority-Reason: nr=8 Received: from [189.250.70.203] (port=36268 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1gWQUj-001EIf-23; Mon, 10 Dec 2018 12:41:30 -0600 Date: Mon, 10 Dec 2018 12:41:24 -0600 From: "Gustavo A. R. Silva" To: "David S. Miller" , Alexey Kuznetsov , Hideaki YOSHIFUJI Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] ipv4: Fix potential Spectre v1 vulnerability Message-ID: <20181210184124.GA24497@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.250.70.203 X-Source-L: No X-Exim-ID: 1gWQUj-001EIf-23 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.70.203]:36268 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 5 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org vr.vifi 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: net/ipv4/ipmr.c:1616 ipmr_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap) net/ipv4/ipmr.c:1690 ipmr_compat_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap) Fix this by sanitizing vr.vifi before using it to index mrt->vif_table' 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://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva --- net/ipv4/ipmr.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index ea04e38f56e9..8c03fb05d3e6 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -69,6 +69,8 @@ #include #include +#include + struct ipmr_rule { struct fib_rule common; }; @@ -1612,6 +1614,7 @@ int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg) return -EFAULT; if (vr.vifi >= mrt->maxvif) return -EINVAL; + vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif); read_lock(&mrt_lock); vif = &mrt->vif_table[vr.vifi]; if (VIF_EXISTS(mrt, vr.vifi)) { @@ -1686,6 +1689,7 @@ int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg) return -EFAULT; if (vr.vifi >= mrt->maxvif) return -EINVAL; + vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif); read_lock(&mrt_lock); vif = &mrt->vif_table[vr.vifi]; if (VIF_EXISTS(mrt, vr.vifi)) { -- 2.17.1