From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932662AbdELBjQ (ORCPT ); Thu, 11 May 2017 21:39:16 -0400 Received: from shards.monkeyblade.net ([184.105.139.130]:56786 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932385AbdELBjP (ORCPT ); Thu, 11 May 2017 21:39:15 -0400 Date: Thu, 11 May 2017 21:39:12 -0400 (EDT) Message-Id: <20170511.213912.1393187351699676007.davem@davemloft.net> To: vkuznets@redhat.com Cc: xen-devel@lists.xenproject.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, boris.ostrovsky@oracle.com, jgross@suse.com Subject: Re: [PATCH v2] xen-netfront: avoid crashing on resume after a failure in talk_to_netback() From: David Miller In-Reply-To: <20170511115806.25322-1-vkuznets@redhat.com> References: <20170511115806.25322-1-vkuznets@redhat.com> X-Mailer: Mew version 6.7 on Emacs 25.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 11 May 2017 17:57:44 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vitaly Kuznetsov Date: Thu, 11 May 2017 13:58:06 +0200 > Unavoidable crashes in netfront_resume() and netback_changed() after a > previous fail in talk_to_netback() (e.g. when we fail to read MAC from > xenstore) were discovered. The failure path in talk_to_netback() does > unregister/free for netdev but we don't reset drvdata and we try accessing > it after resume. > > Fix the bug by removing the whole xen device completely with > device_unregister(), this guarantees we won't have any calls into netfront > after a failure. > > Signed-off-by: Vitaly Kuznetsov > --- > Changes since v1: instead of cleaning drvdata and checking for it in > netfront_resume() and netback_changed() remove the device completely with > device_unregister() [David Miller] This looks a lot better, applied, thanks!