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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 AA1BAECDFBB for ; Fri, 20 Jul 2018 12:25:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D1DF206B7 for ; Fri, 20 Jul 2018 12:25:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D1DF206B7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org 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 S1731364AbeGTNNY (ORCPT ); Fri, 20 Jul 2018 09:13:24 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34634 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731191AbeGTNNY (ORCPT ); Fri, 20 Jul 2018 09:13:24 -0400 Received: from localhost (LFbn-1-12238-233.w90-92.abo.wanadoo.fr [90.92.53.233]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id A3471BBF; Fri, 20 Jul 2018 12:25:24 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tetsuo Handa , syzbot , Jens Axboe Subject: [PATCH 3.18 12/29] loop: remember whether sysfs_create_group() was done Date: Fri, 20 Jul 2018 14:11:07 +0200 Message-Id: <20180720115159.421509745@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180720115158.974693829@linuxfoundation.org> References: <20180720115158.974693829@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tetsuo Handa commit d3349b6b3c373ac1fbfb040b810fcee5e2adc7e0 upstream. syzbot is hitting WARN() triggered by memory allocation fault injection [1] because loop module is calling sysfs_remove_group() when sysfs_create_group() failed. Fix this by remembering whether sysfs_create_group() succeeded. [1] https://syzkaller.appspot.com/bug?id=3f86c0edf75c86d2633aeb9dd69eccc70bc7e90b Signed-off-by: Tetsuo Handa Reported-by: syzbot Reviewed-by: Greg Kroah-Hartman Renamed sysfs_ready -> sysfs_inited. Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/block/loop.c | 11 ++++++----- drivers/block/loop.h | 1 + 2 files changed, 7 insertions(+), 5 deletions(-) --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -803,16 +803,17 @@ static struct attribute_group loop_attri .attrs= loop_attrs, }; -static int loop_sysfs_init(struct loop_device *lo) +static void loop_sysfs_init(struct loop_device *lo) { - return sysfs_create_group(&disk_to_dev(lo->lo_disk)->kobj, - &loop_attribute_group); + lo->sysfs_inited = !sysfs_create_group(&disk_to_dev(lo->lo_disk)->kobj, + &loop_attribute_group); } static void loop_sysfs_exit(struct loop_device *lo) { - sysfs_remove_group(&disk_to_dev(lo->lo_disk)->kobj, - &loop_attribute_group); + if (lo->sysfs_inited) + sysfs_remove_group(&disk_to_dev(lo->lo_disk)->kobj, + &loop_attribute_group); } static void loop_config_discard(struct loop_device *lo) --- a/drivers/block/loop.h +++ b/drivers/block/loop.h @@ -60,6 +60,7 @@ struct loop_device { wait_queue_head_t lo_event; /* wait queue for incoming requests */ wait_queue_head_t lo_req_wait; + bool sysfs_inited; struct request_queue *lo_queue; struct gendisk *lo_disk;