From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755555Ab2JIN0g (ORCPT ); Tue, 9 Oct 2012 09:26:36 -0400 Received: from mail-qa0-f46.google.com ([209.85.216.46]:62862 "EHLO mail-qa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753846Ab2JIN0c (ORCPT ); Tue, 9 Oct 2012 09:26:32 -0400 Message-ID: <50742600.10606@gmail.com> Date: Tue, 09 Oct 2012 09:26:24 -0400 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120913 Thunderbird/15.0.1 MIME-Version: 1.0 To: Jiri Kosina CC: Jan Kara , Tejun Heo , axboe@kernel.dk, Dave Jones , "linux-kernel@vger.kernel.org" , ben@decadent.org.uk Subject: Re: blk: NULL ptr deref in blk_dequeue_request() References: <505E2108.2060108@gmail.com> <20121008172207.GB14767@quack.suse.cz> <507424F7.60801@gmail.com> In-Reply-To: <507424F7.60801@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/09/2012 09:21 AM, Sasha Levin wrote: > On 10/08/2012 05:45 PM, Jiri Kosina wrote: >> On Mon, 8 Oct 2012, Jan Kara wrote: >> >>>>>> I'm still seeing this on linux-next. >>>> I think this is floppy related (see redo_fd_request() in the stack >>>> trace). And there were quite some changes to the area recently. Adding >>>> maintainer to CC. >> Hmm ... I don't immediately see how this is happening. >> >> Sasha, could you please do git bisect on drivers/block/floppy.c between >> f6365201d and your git HEAD for starters (assuming that f6365201d works >> well for you?). >> > > A bisect on floppy.c yielded the following: > > b33d002f4b6bae912463e5a66387c498aa69b6fe is the first bad commit > commit b33d002f4b6bae912463e5a66387c498aa69b6fe > Author: Ben Hutchings > Date: Mon Aug 27 20:56:53 2012 -0300 > > genhd: Make put_disk() safe for disks that have not been registered 2 more things: 1. The guest vm which I'm testing on doesn't emulate anything which even looks like a floppy. 2. I'm seeing the following lines before the BUG: [ 9.836604] floppy0: no floppy controllers found [ 9.837246] work still pending [ 9.837743] floppy0: floppy_shutdown: timeout handler died. Thanks, Sasha