linux-kernel - Re: Linux 3.0 oopses when pulling a USB CDROM

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.44L0.1107041202170.12242-100000@netrider.rowland.org>
Date:	Mon, 4 Jul 2011 12:04:54 -0400 (EDT)
From:	Alan Stern <stern@...land.harvard.edu>
To:	Heiko Carstens <heiko.carstens@...ibm.com>
cc:	axboe@...nel.dk,
	James Bottomley <James.Bottomley@...senPartnership.com>,
	Andi Kleen <andi@...stfloor.org>,
	Dave Jones <davej@...hat.com>,
	SCSI development list <linux-scsi@...r.kernel.org>,
	Kernel development list <linux-kernel@...r.kernel.org>,
	"Rafael J. Wysocki" <rjw@...k.pl>,
	USB list <linux-usb@...r.kernel.org>
Subject: Re: Linux 3.0 oopses when pulling a USB CDROM

On Mon, 4 Jul 2011, Heiko Carstens wrote:

> On Sat, Jul 02, 2011 at 01:37:59PM -0400, Alan Stern wrote:
> > The second bug, which hit me but apparently not any of you, is that the 
> > request_queue's elevator gets deallocated while it is still in use.  
> > That's because __scsi_remove_device() calls scsi_free_queue(), which 
> > does blk_cleanup_queue(), which calls elevator_exit(), even though the 
> > device file is still open and more requests will be submitted when the 
> > file is closed.
> > 
> > I'm not sure of the right fix for this.  One possibility is to move the 
> > scsi_free_queue() call to scsi_device_dev_release_usercontext().  Or 
> > maybe the elevator_exit() call should be moved to blk_release_queue().
> > 
> > Also, I have no idea why this shows up with USB drives but not other 
> > SCSI transports.  A fluke of timing?
> 
> FWIW, I reported a bug where the request_queue's elevator got deallocated
> while it was still in use (fc transport with device hotplug):
> 
> http://www.spinics.net/lists/linux-scsi/msg52879.html

That does sound like the second bug I encountered.  Can you reproduce 
it?  Does the patch here:

	http://marc.info/?l=linux-kernel&m=130963676907731&w=2

fix the problem?

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/