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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 2AD68C04AA5 for ; Mon, 15 Oct 2018 14:26:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E4C9320644 for ; Mon, 15 Oct 2018 14:26:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E4C9320644 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com 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 S1726867AbeJOWLn (ORCPT ); Mon, 15 Oct 2018 18:11:43 -0400 Received: from smtp.nue.novell.com ([195.135.221.5]:52808 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726561AbeJOWLn (ORCPT ); Mon, 15 Oct 2018 18:11:43 -0400 Received: from emea4-mta.ukb.novell.com ([10.120.13.87]) by smtp.nue.novell.com with ESMTP (TLS encrypted); Mon, 15 Oct 2018 16:26:11 +0200 Received: from [192.168.1.2] (nwb-a10-snat.microfocus.com [10.120.13.202]) by emea4-mta.ukb.novell.com with ESMTP (TLS encrypted); Mon, 15 Oct 2018 15:26:02 +0100 Message-ID: Subject: Re: [PATCH v2] xen/blkfront: avoid NULL blkfront_info dereference on device removal From: Vasilis Liaskovitis To: Roger Pau =?ISO-8859-1?Q?Monn=E9?= Cc: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, jgross@suse.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com, axboe@kernel.dk Date: Mon, 15 Oct 2018 16:25:56 +0200 In-Reply-To: <20181015140201.elir7ettk7sz4aix@mac.bytemobile.com> References: <20181015132508.23293-1-vliaskovitis@suse.com> <20181015140201.elir7ettk7sz4aix@mac.bytemobile.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2018-10-15 at 16:02 +0200, Roger Pau Monné wrote: > > > This results in a NULL pointer BUG when blkfront_remove and > > blkif_free > > try to access the failing device's NULL struct blkfront_info. > > > > > I guess this is a candidate for backporting? > yes, I think so. At least for kernels >=4.5, which could face this issue due to commit c31ecf6c12 (this frees the struct blkinfo in the failing path of talk_to_blkback). thanks, - Vasilis