From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Yewang Subject: Re: possible kernel oops from user MSS Date: Tue, 23 Nov 2010 10:48:46 +0800 Message-ID: <4CEB2B8E.3090904@cn.fujitsu.com> References: <20101110.124119.102563803.davem@davemloft.net> <4CDDC6EE.2010005@mvista.com> <20101112.152607.193708973.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: mzhang@mvista.com, netdev@vger.kernel.org To: David Miller Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:54774 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751016Ab0KWCti (ORCPT ); Mon, 22 Nov 2010 21:49:38 -0500 In-Reply-To: <20101112.152607.193708973.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: At 2010-11-13 7:26, David Miller wrote: > From: Min Zhang > Date: Fri, 12 Nov 2010 14:59:58 -0800 > >> Regarding commit 7a1abd08d52fdeddb3e9a5a33f2f15cc6a5674d2 ("tcp: >> Increase TCP_MAXSEG socket option minimum"). What is the reason >> TCP_MAXSEG minimum be 64? Isn't the exact be 40 which is >> TCPOLEN_MD5SIG_ALIGNED(20) + TCPOLEN_TSTAMP_ALIGNED(12) + 8? >> >> Or is it better to use TCP_MIN_MSS from tcp.h: >> >> /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ >> #define TCP_MIN_MSS 88U > > I suppose TCP_MIN_MSS would be better to use, I'll make that > change, thanks. David, do you have plan to fix this bug using TCP_MIN_MSS?