From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753081AbdJFJPN (ORCPT ); Fri, 6 Oct 2017 05:15:13 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49676 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753006AbdJFIzs (ORCPT ); Fri, 6 Oct 2017 04:55:48 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Phil Sutter , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 4.9 090/104] netfilter: nf_tables: set pktinfo->thoff at AH header if found Date: Fri, 6 Oct 2017 10:52:08 +0200 Message-Id: <20171006083854.183797570@linuxfoundation.org> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171006083840.743659740@linuxfoundation.org> References: <20171006083840.743659740@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pablo Neira Ayuso [ Upstream commit 568af6de058cb2b0c5b98d98ffcf37cdc6bc38a7 ] Phil Sutter reports that IPv6 AH header matching is broken. From userspace, nft generates bytecode that expects to find the AH header at NFT_PAYLOAD_TRANSPORT_HEADER both for IPv4 and IPv6. However, pktinfo->thoff is set to the inner header after the AH header in IPv6, while in IPv4 pktinfo->thoff points to the AH header indeed. This behaviour is inconsistent. This patch fixes this problem by updating ipv6_find_hdr() to get the IP6_FH_F_AUTH flag so this function stops at the AH header, so both IPv4 and IPv6 pktinfo->thoff point to the AH header. This is also inconsistent when trying to match encapsulated headers: 1) A packet that looks like IPv4 + AH + TCP dport 22 will *not* match. 2) A packet that looks like IPv6 + AH + TCP dport 22 will match. Reported-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- include/net/netfilter/nf_tables_ipv6.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/include/net/netfilter/nf_tables_ipv6.h +++ b/include/net/netfilter/nf_tables_ipv6.h @@ -9,12 +9,13 @@ nft_set_pktinfo_ipv6(struct nft_pktinfo struct sk_buff *skb, const struct nf_hook_state *state) { + unsigned int flags = IP6_FH_F_AUTH; int protohdr, thoff = 0; unsigned short frag_off; nft_set_pktinfo(pkt, skb, state); - protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, NULL); + protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, &flags); if (protohdr < 0) { nft_set_pktinfo_proto_unspec(pkt, skb); return; @@ -32,6 +33,7 @@ __nft_set_pktinfo_ipv6_validate(struct n const struct nf_hook_state *state) { #if IS_ENABLED(CONFIG_IPV6) + unsigned int flags = IP6_FH_F_AUTH; struct ipv6hdr *ip6h, _ip6h; unsigned int thoff = 0; unsigned short frag_off; @@ -50,7 +52,7 @@ __nft_set_pktinfo_ipv6_validate(struct n if (pkt_len + sizeof(*ip6h) > skb->len) return -1; - protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, NULL); + protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, &flags); if (protohdr < 0) return -1;