From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932604AbdEKL6L (ORCPT ); Thu, 11 May 2017 07:58:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58660 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932385AbdEKL6K (ORCPT ); Thu, 11 May 2017 07:58:10 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 8142C3D945 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=vkuznets@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 8142C3D945 From: Vitaly Kuznetsov To: xen-devel@lists.xenproject.org Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Boris Ostrovsky , Juergen Gross , David Miller Subject: [PATCH v2] xen-netfront: avoid crashing on resume after a failure in talk_to_netback() Date: Thu, 11 May 2017 13:58:06 +0200 Message-Id: <20170511115806.25322-1-vkuznets@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Thu, 11 May 2017 11:58:10 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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] --- drivers/net/xen-netfront.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 6ffc482..7b61adb 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -1934,8 +1934,7 @@ static int talk_to_netback(struct xenbus_device *dev, xennet_disconnect_backend(info); xennet_destroy_queues(info); out: - unregister_netdev(info->netdev); - xennet_free_netdev(info->netdev); + device_unregister(&dev->dev); return err; } -- 2.9.3