From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: Re: [PATCH v2] net/bridge: Use __in6_dev_get rather than in6_dev_get in br_validate_ipv6 Date: Wed, 8 Jul 2015 11:04:21 +0200 Message-ID: <20150708090421.GA4824@salvia> References: <1436280921-2795-1-git-send-email-julien.grall@citrix.com> <20150707113434.25f77b1e@urahara> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Julien Grall , xen-devel@lists.xenproject.org, kaber@trash.net, kadlec@blackhole.kfki.hu, davem@davemloft.net, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, bridge@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Bernhard Thaler , fw@strlen.de, ian.campbell@citrix.com, wei.liu2@citrix.com, Bob Liu To: Stephen Hemminger Return-path: Received: from mail.us.es ([193.147.175.20]:36880 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758201AbbGHI6s (ORCPT ); Wed, 8 Jul 2015 04:58:48 -0400 Content-Disposition: inline In-Reply-To: <20150707113434.25f77b1e@urahara> Sender: netfilter-devel-owner@vger.kernel.org List-ID: On Tue, Jul 07, 2015 at 11:34:34AM -0700, Stephen Hemminger wrote: > On Tue, 7 Jul 2015 15:55:21 +0100 > Julien Grall wrote: > > > The commit efb6de9b4ba0092b2c55f6a52d16294a8a698edd "netfilter: bridge: > > forward IPv6 fragmented packets" introduced a new function > > br_validate_ipv6 which take a reference on the inet6 device. Although, > > the reference is not released at the end. > > > > This will result to the impossibility to destroy any netdevice using > > ipv6 and bridge. > > > > It's possible to directly retrieve the inet6 device without taking a > > reference as all netfilter hooks are protected by rcu_read_lock via > > nf_hook_slow. > > > > Spotted while trying to destroy a Xen guest on the upstream Linux: > > "unregister_netdevice: waiting for vif1.0 to become free. Usage count = 1" > > > > Signed-off-by: Julien Grall > > Cc: Bernhard Thaler > > Cc: Pablo Neira Ayuso > > Cc: fw@strlen.de > > Cc: ian.campbell@citrix.com > > Cc: wei.liu2@citrix.com > > Cc: Bob Liu > > > > --- > > Note that it's impossible to create new guest after this message. > > I'm not sure if it's normal. > > > > Changes in v2: > > - Don't take a reference to inet6. > > - This was "net/bridge: Add missing in6_dev_put in > > br_validate_ipv6" [0] > > > > [0] https://lkml.org/lkml/2015/7/3/443 > > --- > > net/bridge/br_netfilter_ipv6.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > I like this simple solution > > Acked-by: Stephen Hemminger Applied, thanks.