From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965673AbaFQVqR (ORCPT ); Tue, 17 Jun 2014 17:46:17 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:53739 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965155AbaFQVqN (ORCPT ); Tue, 17 Jun 2014 17:46:13 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Florian Westphal , Pablo Neira Ayuso , Kamal Mostafa Subject: [PATCH 3.13 064/212] netfilter: ipv4: defrag: set local_df flag on defragmented skb Date: Tue, 17 Jun 2014 14:42:38 -0700 Message-Id: <1403041506-13646-65-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1403041506-13646-1-git-send-email-kamal@canonical.com> References: <1403041506-13646-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal commit 895162b1101b3ea5db08ca6822ae9672717efec0 upstream. else we may fail to forward skb even if original fragments do fit outgoing link mtu: 1. remote sends 2k packets in two 1000 byte frags, DF set 2. we want to forward but only see '2k > mtu and DF set' 3. we then send icmp error saying that outgoing link is 1500 But original sender never sent a packet that would not fit the outgoing link. Setting local_df makes outgoing path test size vs. IPCB(skb)->frag_max_size, so we will still send the correct error in case the largest original size did not fit outgoing link mtu. Reported-by: Maxime Bizon Suggested-by: Maxime Bizon Fixes: 5f2d04f1f9 (ipv4: fix path MTU discovery with connection tracking) Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Kamal Mostafa --- net/ipv4/netfilter/nf_defrag_ipv4.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv4/netfilter/nf_defrag_ipv4.c b/net/ipv4/netfilter/nf_defrag_ipv4.c index 12e13bd..f40f321 100644 --- a/net/ipv4/netfilter/nf_defrag_ipv4.c +++ b/net/ipv4/netfilter/nf_defrag_ipv4.c @@ -22,7 +22,6 @@ #endif #include -/* Returns new sk_buff, or NULL */ static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user) { int err; @@ -33,8 +32,10 @@ static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user) err = ip_defrag(skb, user); local_bh_enable(); - if (!err) + if (!err) { ip_send_check(ip_hdr(skb)); + skb->local_df = 1; + } return err; } -- 1.9.1