From patchwork Wed Jan 8 19:13:24 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 308405 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 07B402C00BC for ; Thu, 9 Jan 2014 06:13:53 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756881AbaAHTNu (ORCPT ); Wed, 8 Jan 2014 14:13:50 -0500 Received: from mail.us.es ([193.147.175.20]:54781 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756008AbaAHTNq (ORCPT ); Wed, 8 Jan 2014 14:13:46 -0500 Received: (qmail 14581 invoked from network); 8 Jan 2014 20:13:44 +0100 Received: from unknown (HELO us.es) (192.168.2.12) by us.es with SMTP; 8 Jan 2014 20:13:44 +0100 Received: (qmail 27411 invoked by uid 507); 8 Jan 2014 19:13:44 -0000 X-Qmail-Scanner-Diagnostics: from 127.0.0.1 by antivirus2 (envelope-from , uid 501) with qmail-scanner-2.10 (clamdscan: 0.98/18327. spamassassin: 3.3.2. Clear:RC:1(127.0.0.1):SA:0(-102.2/7.5):. Processed in 5.229668 secs); 08 Jan 2014 19:13:44 -0000 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on antivirus2 X-Spam-Level: X-Spam-Status: No, score=-102.2 required=7.5 tests=ALL_TRUSTED,BAYES_50, SMTPAUTH_US,USER_IN_WHITELIST autolearn=disabled version=3.3.2 X-Spam-ASN: X-Envelope-From: pablo@netfilter.org Received: from unknown (HELO antivirus2) (127.0.0.1) by us.es with SMTP; 8 Jan 2014 19:13:39 -0000 Received: from 192.168.1.13 (192.168.1.13) by antivirus2 (F-Secure/fsigk_smtp/412/antivirus2); Wed, 08 Jan 2014 20:13:39 +0100 (CET) X-Virus-Status: clean(F-Secure/fsigk_smtp/412/antivirus2) Received: (qmail 8086 invoked from network); 8 Jan 2014 20:13:39 +0100 Received: from unknown (HELO soleta.us.es) (pneira@us.es@10.100.3.147) by mail.us.es with SMTP; 8 Jan 2014 20:13:39 +0100 From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org Subject: [PATCH 3/3] netfilter: nf_conntrack_dccp: fix skb_header_pointer API usages Date: Wed, 8 Jan 2014 20:13:24 +0100 Message-Id: <1389208404-3956-4-git-send-email-pablo@netfilter.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1389208404-3956-1-git-send-email-pablo@netfilter.org> References: <1389208404-3956-1-git-send-email-pablo@netfilter.org> Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org From: Daniel Borkmann Some occurences in the netfilter tree use skb_header_pointer() in the following way ... struct dccp_hdr _dh, *dh; ... skb_header_pointer(skb, dataoff, sizeof(_dh), &dh); ... where dh itself is a pointer that is being passed as the copy buffer. Instead, we need to use &_dh as the forth argument so that we're copying the data into an actual buffer that sits on the stack. Currently, we probably could overwrite memory on the stack (e.g. with a possibly mal-formed DCCP packet), but unintentionally, as we only want the buffer to be placed into _dh variable. Fixes: 2bc780499aa3 ("[NETFILTER]: nf_conntrack: add DCCP protocol support") Signed-off-by: Daniel Borkmann Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_proto_dccp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/netfilter/nf_conntrack_proto_dccp.c b/net/netfilter/nf_conntrack_proto_dccp.c index 3841268..cb372f9 100644 --- a/net/netfilter/nf_conntrack_proto_dccp.c +++ b/net/netfilter/nf_conntrack_proto_dccp.c @@ -428,7 +428,7 @@ static bool dccp_new(struct nf_conn *ct, const struct sk_buff *skb, const char *msg; u_int8_t state; - dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &dh); + dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh); BUG_ON(dh == NULL); state = dccp_state_table[CT_DCCP_ROLE_CLIENT][dh->dccph_type][CT_DCCP_NONE]; @@ -486,7 +486,7 @@ static int dccp_packet(struct nf_conn *ct, const struct sk_buff *skb, u_int8_t type, old_state, new_state; enum ct_dccp_roles role; - dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &dh); + dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh); BUG_ON(dh == NULL); type = dh->dccph_type; @@ -577,7 +577,7 @@ static int dccp_error(struct net *net, struct nf_conn *tmpl, unsigned int cscov; const char *msg; - dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &dh); + dh = skb_header_pointer(skb, dataoff, sizeof(_dh), &_dh); if (dh == NULL) { msg = "nf_ct_dccp: short packet "; goto out_invalid;