From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yanko Kaneti Subject: Re: [0/8] netpoll/bridge fixes Date: Tue, 29 Jun 2010 15:53:51 +0300 Message-ID: <1277816031.3640.14.camel@d2> References: <20100610124047.GA16658@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Cc: "Michael S.Tsirkin" , Qianfeng Zhang , "David S.Miller" , netdev@vger.kernel.org, WANG Cong , Stephen Hemminger , Matt Mackall To: Herbert Xu Return-path: Received: from indigo.declera.com ([212.116.131.21]:57488 "HELO indigo.declera.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754652Ab0F2NAq (ORCPT ); Tue, 29 Jun 2010 09:00:46 -0400 In-Reply-To: <20100610124047.GA16658@gondor.apana.org.au> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 2010-06-10 at 22:40 +1000, Herbert Xu wrote: > Hi: > > Qianfeng Zhang reported that he was seeing crashes with the > attached backtrace. > > I tracked this down to the recently added netpoll support in > the bridge device. It's a classic use-after-free problem. > > Trying to solve it brought out a host of other issues, some of > which existed prior to the new bridge code. The following patches > attempt to address some of these issues. > > Warning, this is completely untested (apart from compiling with > everything enabled) so please look but don't merge :) FWIW 2.6.35-0.2.rc3.git0.fc14.x86_64 and later rawhide kernels are causing quite reproducible __br_deliver crashes on routine f13 netinstalls in a kvm guest here. To test I cherry picked this series + netpoll-Use-correct-primitives-for-RCU-dereferencing and net-fix-netpoll-Allow-netpoll_setup-cleanup-recursion from net-next on top of 2.6.35-0.15.rc3.git3.fc14.x86_64 (which is todays linus tree) and it seems to fix the crashes for me. Perhaps the netpoll fixes should find their way to a rc before 2.6.35 goes golden. Regards Yanko