From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net] net: fix inet_getid() and ipv6_select_ident() bugs Date: Mon, 02 Jun 2014 14:10:13 -0700 (PDT) Message-ID: <20140602.141013.742158259109147373.davem@davemloft.net> References: <1401378314.3645.44.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: eric.dumazet@gmail.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:36838 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753173AbaFBVKO (ORCPT ); Mon, 2 Jun 2014 17:10:14 -0400 In-Reply-To: <1401378314.3645.44.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Thu, 29 May 2014 08:45:14 -0700 > From: Eric Dumazet > > I noticed we were sending wrong IPv4 ID in TCP flows when MTU discovery > is disabled. > Note how GSO/TSO packets do not have monotonically incrementing ID. > > 06:37:41.575531 IP (id 14227, proto: TCP (6), length: 4396) > 06:37:41.575534 IP (id 14272, proto: TCP (6), length: 65212) > 06:37:41.575544 IP (id 14312, proto: TCP (6), length: 57972) > 06:37:41.575678 IP (id 14317, proto: TCP (6), length: 7292) > 06:37:41.575683 IP (id 14361, proto: TCP (6), length: 63764) > > It appears I introduced this bug in linux-3.1. > > inet_getid() must return the old value of peer->ip_id_count, > not the new one. > > Lets revert this part, and remove the prevention of > a null identification field in IPv6 Fragment Extension Header, > which is dubious and not even done properly. > > Fixes: 87c48fa3b463 ("ipv6: make fragment identifications less predictable") > Signed-off-by: Eric Dumazet Applied and queued up for -stable, thanks for the heads up about the merge conflict with net-next.