From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753825AbdBPAaa (ORCPT ); Wed, 15 Feb 2017 19:30:30 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:53697 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753707AbdBOXKO (ORCPT ); Wed, 15 Feb 2017 18:10:14 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David S. Miller" , "Jakub Sitnicki" , "Hannes Frederic Sowa" Date: Wed, 15 Feb 2017 22:41:40 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 193/306] ipv6: Don't use ufo handling on later transformed packets In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.40-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jakub Sitnicki commit f89c56ce710afa65e1b2ead555b52c4807f34ff7 upstream. Similar to commit c146066ab802 ("ipv4: Don't use ufo handling on later transformed packets"), don't perform UFO on packets that will be IPsec transformed. To detect it we rely on the fact that headerlen in dst_entry is non-zero only for transformation bundles (xfrm_dst objects). Unwanted segmentation can be observed with a NETIF_F_UFO capable device, such as a dummy device: DEV=dum0 LEN=1493 ip li add $DEV type dummy ip addr add fc00::1/64 dev $DEV nodad ip link set $DEV up ip xfrm policy add dir out src fc00::1 dst fc00::2 \ tmpl src fc00::1 dst fc00::2 proto esp spi 1 ip xfrm state add src fc00::1 dst fc00::2 \ proto esp spi 1 enc 'aes' 0x0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b tcpdump -n -nn -i $DEV -t & socat /dev/zero,readbytes=$LEN udp6:[fc00::2]:$LEN tcpdump output before: IP6 fc00::1 > fc00::2: frag (0|1448) ESP(spi=0x00000001,seq=0x1), length 1448 IP6 fc00::1 > fc00::2: frag (1448|48) IP6 fc00::1 > fc00::2: ESP(spi=0x00000001,seq=0x2), length 88 ... and after: IP6 fc00::1 > fc00::2: frag (0|1448) ESP(spi=0x00000001,seq=0x1), length 1448 IP6 fc00::1 > fc00::2: frag (1448|80) Fixes: e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach") Signed-off-by: Jakub Sitnicki Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- net/ipv6/ip6_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1296,7 +1296,7 @@ emsgsize: if (((length > mtu) || (skb && skb_is_gso(skb))) && (sk->sk_protocol == IPPROTO_UDP) && - (rt->dst.dev->features & NETIF_F_UFO) && + (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len && (sk->sk_type == SOCK_DGRAM)) { err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len, fragheaderlen, exthdrlen,