From patchwork Fri Mar 3 22:08:29 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Pfaff X-Patchwork-Id: 735249 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3vZjxv5dbSz9ryQ for ; Sat, 4 Mar 2017 09:08:51 +1100 (AEDT) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 03392104D; Fri, 3 Mar 2017 22:08:48 +0000 (UTC) X-Original-To: dev@openvswitch.org Delivered-To: ovs-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id F147E1037 for ; Fri, 3 Mar 2017 22:08:45 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [217.70.183.197]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id A7C6D16D for ; Fri, 3 Mar 2017 22:08:44 +0000 (UTC) Received: from mfilter13-d.gandi.net (mfilter13-d.gandi.net [217.70.178.141]) by relay5-d.mail.gandi.net (Postfix) with ESMTP id 20DD341C091; Fri, 3 Mar 2017 23:08:43 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at mfilter13-d.gandi.net Received: from relay5-d.mail.gandi.net ([IPv6:::ffff:217.70.183.197]) by mfilter13-d.gandi.net (mfilter13-d.gandi.net [::ffff:10.0.15.180]) (amavisd-new, port 10024) with ESMTP id lBH4qkUxvmNI; Fri, 3 Mar 2017 23:08:41 +0100 (CET) X-Originating-IP: 208.91.2.3 Received: from sigabrt.benpfaff.org (unknown [208.91.2.3]) (Authenticated sender: blp@ovn.org) by relay5-d.mail.gandi.net (Postfix) with ESMTPSA id 3255341C08A; Fri, 3 Mar 2017 23:08:38 +0100 (CET) From: Ben Pfaff To: dev@openvswitch.org Date: Fri, 3 Mar 2017 14:08:29 -0800 Message-Id: <20170303220829.22050-1-blp@ovn.org> X-Mailer: git-send-email 2.10.2 X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: Ben Pfaff , Bhargava Shastry Subject: [ovs-dev] [PATCH] conntrack: Fix checks for TCP, UDP, and IPv6 header sizes. X-BeenThere: ovs-dev@openvswitch.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ovs-dev-bounces@openvswitch.org Errors-To: ovs-dev-bounces@openvswitch.org Otherwise a malformed packet could cause a read up to about 40 bytes past the end of the packet. The packet would still likely be dropped because of checksum verification. Reported-by: Bhargava Shastry Signed-off-by: Ben Pfaff Acked-by: Daniele Di Proietto --- lib/conntrack.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/lib/conntrack.c b/lib/conntrack.c index 9bea3d93e4ad..9c1dd63648b8 100644 --- a/lib/conntrack.c +++ b/lib/conntrack.c @@ -568,6 +568,10 @@ extract_l3_ipv6(struct conn_key *key, const void *data, size_t size, const char **new_data) { const struct ovs_16aligned_ip6_hdr *ip6 = data; + if (size < sizeof *ip6) { + return false; + } + uint8_t nw_proto = ip6->ip6_nxt; uint8_t nw_frag = 0; @@ -623,8 +627,11 @@ check_l4_tcp(const struct conn_key *key, const void *data, size_t size, const void *l3) { const struct tcp_header *tcp = data; - size_t tcp_len = TCP_OFFSET(tcp->tcp_ctl) * 4; + if (size < sizeof *tcp) { + return false; + } + size_t tcp_len = TCP_OFFSET(tcp->tcp_ctl) * 4; if (OVS_UNLIKELY(tcp_len < TCP_HEADER_LEN || tcp_len > size)) { return false; } @@ -637,8 +644,11 @@ check_l4_udp(const struct conn_key *key, const void *data, size_t size, const void *l3) { const struct udp_header *udp = data; - size_t udp_len = ntohs(udp->udp_len); + if (size < sizeof *udp) { + return false; + } + size_t udp_len = ntohs(udp->udp_len); if (OVS_UNLIKELY(udp_len < UDP_HEADER_LEN || udp_len > size)) { return false; }