From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH stable 4.4 0/9] fix SegmentSmack (CVE-2018-5390) Date: Wed, 15 Aug 2018 17:41:31 +0200 Message-ID: <20180815154131.GA12619@kroah.com> References: <1534339268-111834-1-git-send-email-maowenan@huawei.com> <20180815132432.GE31330@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: dwmw2@infradead.org, netdev@vger.kernel.org, eric.dumazet@gmail.com, edumazet@google.com, davem@davemloft.net, ycheng@google.com, jdw@amazon.de To: Mao Wenan Return-path: Received: from out1-smtp.messagingengine.com ([66.111.4.25]:50843 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729300AbeHOSe3 (ORCPT ); Wed, 15 Aug 2018 14:34:29 -0400 Content-Disposition: inline In-Reply-To: <20180815132432.GE31330@kroah.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Aug 15, 2018 at 03:24:32PM +0200, Greg KH wrote: > On Wed, Aug 15, 2018 at 09:20:59PM +0800, Mao Wenan wrote: > > There are five patches to fix CVE-2018-5390 in latest mainline > > branch, but only two patches exist in stable 4.4 and 3.18: > > dc6ae4d tcp: detect malicious patterns in tcp_collapse_ofo_queue() > > 5fbec48 tcp: avoid collapses in tcp_prune_queue() if possible > > but I have tested with these patches, and found the cpu usage was very high. > > test results: > > with fix patch： 78.2% ksoftirqd > > no fix patch： 90% ksoftirqd > > > > After analysing the codes of stable 4.4, and debuging the > > system, the search of ofo_queue(tcp ofo using a simple queue) cost more cycles. > > So I think only two patches can't fix the CVE-2018-5390. > > So I try to backport "tcp: use an RB tree for ooo receive queue" using RB tree > > instead of simple queue, then backport Eric Dumazet 5 fixed patches in mainline, > > good news is that ksoftirqd is turn to about 20%, which is the same with mainline now. > > Thanks for doing this work, I had some questions on the individual > patches. Can you address them and resend? Also, always cc: the stable@vger list when sending stable patches so that others can review and comment on them. thanks, greg k-h