From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: Bug in net/ipv6/ip6_fib.c:fib6_dump_table() Date: Thu, 21 Jun 2012 22:27:49 +0200 Message-ID: <1340310469.4604.6702.camel@edumazet-glaptop> References: <4FE37783.9000409@akamai.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: "davem@davemloft.net" , "kaber@trash.net" , Debabrata Banerjee , "netdev@vger.kernel.org" , "yoshfuji@linux-ipv6.org" , "jmorris@namei.org" , "pekkas@netcore.fi" , "kuznet@ms2.inr.ac.ru" , "linux-kernel@vger.kernel.org" To: Josh Hunt Return-path: In-Reply-To: <4FE37783.9000409@akamai.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Thu, 2012-06-21 at 14:35 -0500, Josh Hunt wrote: > Can anyone provide details of the crash which was intended to be fixed > by 2bec5a369ee79576a3eea2c23863325089785a2c? With this patch in and > doing concurrent adds/deletes and dumping the table via netlink causes > duplicate entries to be reported. Reverting this patch causes those > problems to go away. We can provide a more detailed test if that is > needed, but so far our testing has been unable to reproduce the crash > mentioned in the above commit with it reverted. A mere revert wont be enough. Looking at this code, it lacks proper synchronization between tree updaters and tree walkers. fib6_walker_lock rwlock is not enough to prevent races. Are you willing to fix this yourself ?