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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 427ECC43441 for ; Mon, 12 Nov 2018 11:02:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 11863223D8 for ; Mon, 12 Nov 2018 11:02:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 11863223D8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz 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 S1729354AbeKLUyr (ORCPT ); Mon, 12 Nov 2018 15:54:47 -0500 Received: from mx2.suse.de ([195.135.220.15]:49140 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728431AbeKLUyr (ORCPT ); Mon, 12 Nov 2018 15:54:47 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 0C2DEB049; Mon, 12 Nov 2018 11:02:01 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 60A301E09A5; Mon, 12 Nov 2018 12:02:00 +0100 (CET) Date: Mon, 12 Nov 2018 12:02:00 +0100 From: Jan Kara To: Tetsuo Handa Cc: axboe@kernel.dk, Jan Kara , syzbot , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: WARNING: locking bug in loop_control_ioctl Message-ID: <20181112110200.GB7175@quack2.suse.cz> References: <00000000000026aaac057a40a183@google.com> <913c3703-f6d3-a412-3b0c-ebc7422e8e69@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <913c3703-f6d3-a412-3b0c-ebc7422e8e69@I-love.SAKURA.ne.jp> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat 10-11-18 17:09:09, Tetsuo Handa wrote: > 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 Yeah, my bad. Thanks for fixing this. You can add: Reviewed-by: Jan Kara Honza > --- > 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 > -- Jan Kara SUSE Labs, CR