Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757233AbbBQLsS (ORCPT ); Tue, 17 Feb 2015 06:48:18 -0500 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:39887 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756957AbbBQLfO (ORCPT ); Tue, 17 Feb 2015 06:35:14 -0500 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Hagen Paul Pfeifer , Fernando Gont , "David S. Miller" , Jiri Slaby Subject: [PATCH 3.12 078/122] ipv6: stop sending PTB packets for MTU < 1280 Date: Tue, 17 Feb 2015 12:34:25 +0100 Message-Id: X-Mailer: git-send-email 2.2.2 In-Reply-To: <09e6fe32192a77f6e2e60cc0f4103e630c7ecf20.1424099973.git.jslaby@suse.cz> References: <09e6fe32192a77f6e2e60cc0f4103e630c7ecf20.1424099973.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1831 Lines: 53 From: Hagen Paul Pfeifer 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ Upstream commit 9d289715eb5c252ae15bd547cb252ca547a3c4f2 ] Reduce the attack vector and stop generating IPv6 Fragment Header for paths with an MTU smaller than the minimum required IPv6 MTU size (1280 byte) - called atomic fragments. See IETF I-D "Deprecating the Generation of IPv6 Atomic Fragments" [1] for more information and how this "feature" can be misused. [1] https://tools.ietf.org/html/draft-ietf-6man-deprecate-atomfrag-generation-00 Signed-off-by: Fernando Gont Signed-off-by: Hagen Paul Pfeifer Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- net/ipv6/route.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index b4bb6a29aa16..1d0c5d66d637 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1144,12 +1144,9 @@ static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, struct net *net = dev_net(dst->dev); rt6->rt6i_flags |= RTF_MODIFIED; - if (mtu < IPV6_MIN_MTU) { - u32 features = dst_metric(dst, RTAX_FEATURES); + if (mtu < IPV6_MIN_MTU) mtu = IPV6_MIN_MTU; - features |= RTAX_FEATURE_ALLFRAG; - dst_metric_set(dst, RTAX_FEATURES, features); - } + dst_metric_set(dst, RTAX_MTU, mtu); rt6_update_expires(rt6, net->ipv6.sysctl.ip6_rt_mtu_expires); } -- 2.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/