Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753578AbcDVLGW (ORCPT ); Fri, 22 Apr 2016 07:06:22 -0400 Received: from mx2.suse.de ([195.135.220.15]:43964 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753142AbcDVLGM (ORCPT ); Fri, 22 Apr 2016 07:06:12 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Florian Westphal , "David S . Miller" , Jiri Slaby Subject: [PATCH 3.12 20/78] ipv6: re-enable fragment header matching in ipv6_find_hdr Date: Fri, 22 Apr 2016 13:05:03 +0200 Message-Id: X-Mailer: git-send-email 2.8.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1655 Lines: 50 From: Florian Westphal 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ Upstream commit 5d150a985520bbe3cb2aa1ceef24a7e32f20c15f ] When ipv6_find_hdr is used to find a fragment header (caller specifies target NEXTHDR_FRAGMENT) we erronously return -ENOENT for all fragments with nonzero offset. Before commit 9195bb8e381d, when target was specified, we did not enter the exthdr walk loop as nexthdr == target so this used to work. Now we do (so we can skip empty route headers). When we then stumble upon a frag with nonzero frag_off we must return -ENOENT ("header not found") only if the caller did not specifically request NEXTHDR_FRAGMENT. This allows nfables exthdr expression to match ipv6 fragments, e.g. via nft add rule ip6 filter input frag frag-off gt 0 Fixes: 9195bb8e381d ("ipv6: improve ipv6_find_hdr() to skip empty routing headers") Signed-off-by: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- net/ipv6/exthdrs_core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c index 8af3eb57f438..c7c8f71d0d48 100644 --- a/net/ipv6/exthdrs_core.c +++ b/net/ipv6/exthdrs_core.c @@ -257,7 +257,11 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, *fragoff = _frag_off; return hp->nexthdr; } - return -ENOENT; + if (!found) + return -ENOENT; + if (fragoff) + *fragoff = _frag_off; + break; } hdrlen = 8; } else if (nexthdr == NEXTHDR_AUTH) { -- 2.8.1