From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Graf Subject: Re: Possible netlink autobind regression Date: Thu, 17 Sep 2015 13:25:05 +0200 Message-ID: <20150917112505.GA27604@pox.localdomain> References: <20150917022909.GA22754@htj.duckdns.org> <20150917030845.GA19162@gondor.apana.org.au> <20150917034134.GA19327@gondor.apana.org.au> <20150917051503.GA19978@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Cong Wang , Tejun Heo , David Miller , Tom Herbert , kafai@fb.com, kernel-team , "linux-kernel@vger.kernel.org" , netdev , Linus Torvalds , Jiri Pirko , Nicolas Dichtel , Scott Feldman To: Herbert Xu Return-path: Content-Disposition: inline In-Reply-To: <20150917051503.GA19978@gondor.apana.org.au> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 09/17/15 at 01:15pm, Herbert Xu wrote: > On Wed, Sep 16, 2015 at 10:02:00PM -0700, Cong Wang wrote: > > > > This part doesn't look correct, seems it is checking if this is a kernel > > netlink socket rather than if it is bound. But I am not sure... > > Good point. I've changed it so that bound is only set for non-kernel > sockets. > > ---8<--- > netlink: Fix autobind race condition that leads to zero port ID > > The commit c0bb07df7d981e4091432754e30c9c720e2c0c78 ("netlink: > Reset portid after netlink_insert failure") introduced a race > condition where if two threads tried to autobind the same socket > one of them may end up with a zero port ID. > > This patch reverts that commit and instead fixes it by introducing > a separte "bound" variable to indicate whether a user-space socket > has been bound. > > Fixes: c0bb07df7d98 ("netlink: Reset portid after netlink_insert failure") > Reported-by: Tejun Heo > Reported-by: Linus Torvalds > Signed-off-by: Herbert Xu > Reviewed-by: Cong Wang Acked-by: Thomas Graf