From mboxrd@z Thu Jan 1 00:00:00 1970 From: Min Zhang Subject: Re: possible kernel oops from user MSS Date: Fri, 12 Nov 2010 14:59:58 -0800 Message-ID: <4CDDC6EE.2010005@mvista.com> References: <20101110.124119.102563803.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from mail-yw0-f46.google.com ([209.85.213.46]:63700 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752140Ab0KLXAI (ORCPT ); Fri, 12 Nov 2010 18:00:08 -0500 Received: by ywc21 with SMTP id 21so911917ywc.19 for ; Fri, 12 Nov 2010 15:00:07 -0800 (PST) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: 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