From patchwork Wed Mar 27 22:11:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrea Righi X-Patchwork-Id: 1067468 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=fail (p=none dis=none) header.from=canonical.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44V2KR2QLwz9sNx for ; Thu, 28 Mar 2019 09:11:55 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726408AbfC0WLx (ORCPT ); Wed, 27 Mar 2019 18:11:53 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:47103 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726055AbfC0WLx (ORCPT ); Wed, 27 Mar 2019 18:11:53 -0400 Received: from mail-wm1-f72.google.com ([209.85.128.72]) by youngberry.canonical.com with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1h9Glz-0005Un-Pf for netdev@vger.kernel.org; Wed, 27 Mar 2019 22:11:51 +0000 Received: by mail-wm1-f72.google.com with SMTP id f67so640507wme.3 for ; Wed, 27 Mar 2019 15:11:51 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=WXjYdAUAnz6+/eYr5Y7Yrp7ylVTll3WJTmB9qgkkyAw=; b=PQEbZYYKNa0/H/FtO0hv2PiTkYcPEvW6etlvYMNr4d8kQwiIfBbhYwKTAYFc5Gpehh fbnJtmPGJkY+skDpcePraTe1LR/G2uh/5sfEG2YS75YxslnNUHxSUKIfE9SERcA/f+kW qP/Y0MIrebUeCDesyDmFBINUiai2/mvHrvPTguepMv43WKj2fkRoLwxWkdrpJ22v7Om4 2ZWSYdpOep0/xzifP22gaXlnYMxrVdL3eSfbUhRKRzIbMpCbU7fbNCrhkQkQ6YOaHmGR hsn90U+4HgyyjxRFXJpi5p0uo89PORNae3myHnDnQfH9Ml5Z7hUTldrkhxOhVudXevh1 QW+Q== X-Gm-Message-State: APjAAAX5J4F4/wY+I5ITKjgC5CDHvMcTxgQay5HL0B+KPt4qV1YJJBOt dmOZUjtRHSLOSwVeGPV1Wdn8HXV64MzHX1MMARJah88iONIMKLdWtydp6cdYRdlkipnOYXGnBfB SW7Ih3ehxCorOrTWCZLjekcaksahNTDPkGg== X-Received: by 2002:adf:e692:: with SMTP id r18mr26623162wrm.231.1553724711241; Wed, 27 Mar 2019 15:11:51 -0700 (PDT) X-Google-Smtp-Source: APXvYqwLjebGTxkNWh5ddJr8xfJP3+1SU4iS1hyl/Xn/2kqvtWKIT2j4IFVTagZuYXFHiPFvAiOs/A== X-Received: by 2002:adf:e692:: with SMTP id r18mr26623150wrm.231.1553724710969; Wed, 27 Mar 2019 15:11:50 -0700 (PDT) Received: from localhost (host141-127-dynamic.17-87-r.retail.telecomitalia.it. [87.17.127.141]) by smtp.gmail.com with ESMTPSA id o17sm22708991wrw.73.2019.03.27.15.11.49 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 27 Mar 2019 15:11:50 -0700 (PDT) Date: Wed, 27 Mar 2019 23:11:49 +0100 From: Andrea Righi To: Pravin B Shelar Cc: "David S. Miller" , netdev@vger.kernel.org, dev@openvswitch.org, linux-kernel@vger.kernel.org Subject: [PATCH] openvswitch: fix flow actions reallocation Message-ID: <20190327221148.GA16096@xps-13> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The flow action buffer can be resized if it's not big enough to contain all the requested flow actions. However, this resize doesn't take into account the new requested size, the buffer is only increased by a factor of 2x. This might be not enough to contain the new data, causing a buffer overflow, for example: [ 42.044472] ============================================================================= [ 42.045608] BUG kmalloc-96 (Not tainted): Redzone overwritten [ 42.046415] ----------------------------------------------------------------------------- [ 42.047715] Disabling lock debugging due to kernel taint [ 42.047716] INFO: 0x8bf2c4a5-0x720c0928. First byte 0x0 instead of 0xcc [ 42.048677] INFO: Slab 0xbc6d2040 objects=29 used=18 fp=0xdc07dec4 flags=0x2808101 [ 42.049743] INFO: Object 0xd53a3464 @offset=2528 fp=0xccdcdebb [ 42.050747] Redzone 76f1b237: cc cc cc cc cc cc cc cc ........ [ 42.051839] Object d53a3464: 6b 6b 6b 6b 6b 6b 6b 6b 0c 00 00 00 6c 00 00 00 kkkkkkkk....l... [ 42.053015] Object f49a30cc: 6c 00 0c 00 00 00 00 00 00 00 00 03 78 a3 15 f6 l...........x... [ 42.054203] Object acfe4220: 20 00 02 00 ff ff ff ff 00 00 00 00 00 00 00 00 ............... [ 42.055370] Object 21024e91: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 42.056541] Object 070e04c3: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 42.057797] Object 948a777a: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 42.059061] Redzone 8bf2c4a5: 00 00 00 00 .... [ 42.060189] Padding a681b46e: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ Fix by making sure the new buffer is properly resized to contain all the requested data. BugLink: https://bugs.launchpad.net/bugs/1813244 Signed-off-by: Andrea Righi --- net/openvswitch/flow_netlink.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c index 691da853bef5..e6f789badaa3 100644 --- a/net/openvswitch/flow_netlink.c +++ b/net/openvswitch/flow_netlink.c @@ -2306,14 +2306,14 @@ static struct nlattr *reserve_sfa_size(struct sw_flow_actions **sfa, struct sw_flow_actions *acts; int new_acts_size; - int req_size = NLA_ALIGN(attr_len); + size_t req_size = NLA_ALIGN(attr_len); int next_offset = offsetof(struct sw_flow_actions, actions) + (*sfa)->actions_len; if (req_size <= (ksize(*sfa) - next_offset)) goto out; - new_acts_size = ksize(*sfa) * 2; + new_acts_size = max(req_size, ksize(*sfa) * 2); if (new_acts_size > MAX_ACTIONS_BUFSIZE) { if ((MAX_ACTIONS_BUFSIZE - next_offset) < req_size) {