From patchwork Fri Dec 21 21:41:17 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 1017734 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=embeddedor.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43M3Bd3895z9sDP for ; Sat, 22 Dec 2018 09:26:33 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390683AbeLUW03 (ORCPT ); Fri, 21 Dec 2018 17:26:29 -0500 Received: from gateway36.websitewelcome.com ([192.185.192.36]:16218 "EHLO gateway36.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730887AbeLUW03 (ORCPT ); Fri, 21 Dec 2018 17:26:29 -0500 X-Greylist: delayed 1436 seconds by postgrey-1.27 at vger.kernel.org; Fri, 21 Dec 2018 17:26:28 EST Received: from cm17.websitewelcome.com (cm17.websitewelcome.com [100.42.49.20]) by gateway36.websitewelcome.com (Postfix) with ESMTP id D8C23400C843D for ; Fri, 21 Dec 2018 14:52:17 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id aSXngWvdw90onaSXng4cVD; Fri, 21 Dec 2018 15:41:19 -0600 X-Authority-Reason: nr=8 Received: from [189.250.106.44] (port=35208 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1gaSXn-000bw3-27; Fri, 21 Dec 2018 15:41:19 -0600 Date: Fri, 21 Dec 2018 15:41:17 -0600 From: "Gustavo A. R. Silva" To: Remi Denis-Courmont , "David S. Miller" Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] phonet: af_phonet: Fix Spectre v1 vulnerability Message-ID: <20181221214117.GA1539@embeddedor> MIME-Version: 1.0 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: 189.250.106.44 X-Source-L: No X-Exim-ID: 1gaSXn-000bw3-27 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.106.44]:35208 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 9 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org protocol 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/phonet/af_phonet.c:48 phonet_proto_get() warn: potential spectre issue 'proto_tab' [w] (local cap) Fix this by sanitizing protocol before using it to index proto_tab. 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 Signed-off-by: Gustavo A. R. Silva --- net/phonet/af_phonet.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c index 3b0ef691f5b1..d4b2abd78858 100644 --- a/net/phonet/af_phonet.c +++ b/net/phonet/af_phonet.c @@ -34,6 +34,8 @@ #include #include +#include + /* Transport protocol registration */ static const struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly; @@ -43,6 +45,7 @@ static const struct phonet_protocol *phonet_proto_get(unsigned int protocol) if (protocol >= PHONET_NPROTO) return NULL; + protocol = array_index_nospec(protocol, PHONET_NPROTO); rcu_read_lock(); pp = rcu_dereference(proto_tab[protocol]);