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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 4931AC43441 for ; Sat, 10 Nov 2018 08:09:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10AE920825 for ; Sat, 10 Nov 2018 08:09:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 10AE920825 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=I-love.SAKURA.ne.jp 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 S1729001AbeKJRxj (ORCPT ); Sat, 10 Nov 2018 12:53:39 -0500 Received: from www262.sakura.ne.jp ([202.181.97.72]:21504 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728659AbeKJRxj (ORCPT ); Sat, 10 Nov 2018 12:53:39 -0500 Received: from fsav405.sakura.ne.jp (fsav405.sakura.ne.jp [133.242.250.104]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id wAA89KUF009360; Sat, 10 Nov 2018 17:09:20 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav405.sakura.ne.jp (F-Secure/fsigk_smtp/530/fsav405.sakura.ne.jp); Sat, 10 Nov 2018 17:09:20 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/530/fsav405.sakura.ne.jp) Received: from [192.168.1.8] (softbank060157065137.bbtec.net [60.157.65.137]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id wAA89BhA009333 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NO); Sat, 10 Nov 2018 17:09:20 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Subject: Re: WARNING: locking bug in loop_control_ioctl To: axboe@kernel.dk, Jan Kara References: <00000000000026aaac057a40a183@google.com> Cc: syzbot , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com From: Tetsuo Handa Message-ID: <913c3703-f6d3-a412-3b0c-ebc7422e8e69@I-love.SAKURA.ne.jp> Date: Sat, 10 Nov 2018 17:09:09 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: <00000000000026aaac057a40a183@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >From 4b9e5556fada37dff1eff13665a229b69e1f7dd8 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Sat, 10 Nov 2018 17:04:40 +0900 Subject: [PATCH] loop: Fix double mutex_unlock(&loop_ctl_mutex) in loop_control_ioctl(). Commit 0a42e99b58a20883 ("loop: Get rid of loop_index_mutex") forgot to remove mutex_unlock(&loop_ctl_mutex) from loop_control_ioctl() when replacing loop_index_mutex with loop_ctl_mutex. Reported-by: syzbot Signed-off-by: Tetsuo Handa Cc: Jan Kara --- drivers/block/loop.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index bf6bc35..176ab1f 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -2074,12 +2074,10 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd, break; if (lo->lo_state != Lo_unbound) { ret = -EBUSY; - mutex_unlock(&loop_ctl_mutex); break; } if (atomic_read(&lo->lo_refcnt) > 0) { ret = -EBUSY; - mutex_unlock(&loop_ctl_mutex); break; } lo->lo_disk->private_data = NULL; -- 1.8.3.1