Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765940AbZDBXdn (ORCPT ); Thu, 2 Apr 2009 19:33:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762837AbZDBXcr (ORCPT ); Thu, 2 Apr 2009 19:32:47 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:54624 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1762623AbZDBXcq convert rfc822-to-8bit (ORCPT ); Thu, 2 Apr 2009 19:32:46 -0400 Date: Thu, 02 Apr 2009 16:32:35 -0700 (PDT) Message-Id: <20090402.163235.153382360.davem@davemloft.net> To: ilpo.jarvinen@helsinki.fi Cc: markus@trippelsdorf.de, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, uwe.bugla@gmx.de Subject: Re: [PATCH 2/2] tcp: miscounts due to tcp_fragment pcount reset From: David Miller In-Reply-To: References: X-Mailer: Mew version 6.1 on Emacs 22.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 935 Lines: 24 From: "Ilpo J?rvinen" Date: Thu, 2 Apr 2009 12:18:20 +0300 (EEST) > > It seems that trivial reset of pcount to one was not sufficient > in tcp_retransmit_skb. Multiple counters experience a positive > miscount when skb's pcount gets lowered without the necessary > adjustments (depending on skb's sacked bits which exactly), at > worst a packets_out miscount can crash at RTO if the write queue > is empty! > > Triggering this requires mss change, so bidir tcp or mtu probe or > like. > > Signed-off-by: Ilpo J?rvinen > Reported-by: Markus Trippelsdorf > Tested-by: Uwe Bugla Applied. -- 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/