From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EAC31C43441 for ; Sun, 11 Nov 2018 20:36:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B8A0620818 for ; Sun, 11 Nov 2018 20:36:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B8A0620818 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730337AbeKLG0W (ORCPT ); Mon, 12 Nov 2018 01:26:22 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:49710 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730069AbeKLFsL (ORCPT ); Mon, 12 Nov 2018 00:48:11 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gLvsW-0000lG-CS; Sun, 11 Nov 2018 19:58:40 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gLvsT-0001b4-6I; Sun, 11 Nov 2018 19:58:37 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David Vrabel" , "David S. Miller" , "Boris Ostrovsky" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 167/366] xen-netfront: properly destroy queues when removing device In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: David Vrabel commit ad0681185770716523c81b156c44b9804d7b8ed2 upstream. xennet_remove() freed the queues before freeing the netdevice which results in a use-after-free when free_netdev() tries to delete the napi instances that have already been freed. Fix this by fully destroy the queues (which includes deleting the napi instances) before freeing the netdevice. Signed-off-by: David Vrabel Reviewed-by: Boris Ostrovsky Signed-off-by: David S. Miller [bwh: Backported to 3.16: I already backported most of this along with the later commit 74470954857c "xen-netfront: Delete rx_refill_timer in xennet_disconnect_backend()"; don't move the del_timer_sync() again.] Signed-off-by: Ben Hutchings --- --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -2294,7 +2294,6 @@ static const struct xenbus_device_id net static int xennet_remove(struct xenbus_device *dev) { struct netfront_info *info = dev_get_drvdata(&dev->dev); - unsigned int num_queues = info->netdev->real_num_tx_queues; dev_dbg(&dev->dev, "%s\n", dev->nodename); @@ -2302,11 +2301,7 @@ static int xennet_remove(struct xenbus_d unregister_netdev(info->netdev); - if (num_queues) { - kfree(info->queues); - info->queues = NULL; - } - + xennet_destroy_queues(info); xennet_free_netdev(info->netdev); return 0;