From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] net dst: fix percpu_counter list corruption and poison overwritten Date: Wed, 03 Nov 2010 18:59:14 -0700 (PDT) Message-ID: <20101103.185914.245411332.davem@davemloft.net> References: <1288750265-17664-1-git-send-email-dfeng@redhat.com> <1288761773.2467.535.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: dfeng@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kuznet@ms2.inr.ac.ru, pekkas@netcore.fi, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net To: eric.dumazet@gmail.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:37031 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754629Ab0KDB6u convert rfc822-to-8bit (ORCPT ); Wed, 3 Nov 2010 21:58:50 -0400 In-Reply-To: <1288761773.2467.535.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: =46rom: Eric Dumazet Date: Wed, 03 Nov 2010 06:22:53 +0100 > Le mercredi 03 novembre 2010 =E0 10:11 +0800, Xiaotian Feng a =E9crit= : >> There're some percpu_counter list corruption and poison overwritten = warnings >> in recent kernel, which is resulted by fc66f95c. >>=20 >> commit fc66f95c switches to use percpu_counter, in ip6_route_net_ini= t, kernel >> init the percpu_counter for dst entries, but, the percpu_counter is = never destroyed >> in ip6_route_net_exit. So if the related data is freed by kernel, th= e freed percpu_counter >> is still on the list, then if we insert/remove other percpu_counter,= list corruption >> resulted. Also, if the insert/remove option modifies the ->prev,->ne= xt pointer of >> the freed value, the poison overwritten is resulted then. >>=20 >> With the following patch, the percpu_counter list corruption and poi= son overwritten >> warnings disappeared. >>=20 >> Signed-off-by: Xiaotian Feng ... > Acked-by: Eric Dumazet Applied, thanks!