linux-kernel - Re: [PATCH] block: fix intermittent dm timeout based oops

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: <1238769345.3359.15.camel@mulgrave.int.hansenpartnership.com>
Date:	Fri, 03 Apr 2009 09:35:45 -0500
From:	James Bottomley <James.Bottomley@...senPartnership.com>
To:	Christof Schmitt <christof.schmitt@...ibm.com>
Cc:	Jens Axboe <jens.axboe@...cle.com>, linux-kernel@...r.kernel.org,
	linux-scsi@...r.kernel.org, Hannes Reinecke <hare@...e.de>
Subject: Re: [PATCH] block: fix intermittent dm timeout based oops

On Fri, 2009-04-03 at 16:32 +0200, Christof Schmitt wrote:
> On Tue, Mar 24, 2009 at 08:17:30AM +0100, Hannes Reinecke wrote:
> > Very rarely under stress testing of dm, oopses are occuring as
> > something tampers with an old stack frame.  This has been traced back
> > to blk_abort_queue() leaving a timeout_list pointing to the stack.
> > The reason is that sometimes blk_abort_request() won't delete the
> > timer (if the request is marked as complete but before the timer has
> > been removed, a small race window).  Fix this by splicing back from
> > the ususally empty list to the q->timeout_list.
> > 
> > Signed-off-by: Hannes Reinecke <hare@...e.de>
> > ---
> >  block/blk-timeout.c |    6 ++++++
> >  1 files changed, 6 insertions(+), 0 deletions(-)
> > 
> > diff --git a/block/blk-timeout.c b/block/blk-timeout.c
> > index bbbdc4b..6213123 100644
> > --- a/block/blk-timeout.c
> > +++ b/block/blk-timeout.c
> > @@ -224,6 +224,12 @@ void blk_abort_queue(struct request_queue *q)
> >  	list_for_each_entry_safe(rq, tmp, &list, timeout_list)
> >  		blk_abort_request(rq);
> > 
> > +	/*
> > +	 * Occasionally, blk_abort_request() will return without
> > +	 * deleting the element from the list
> > +	 */
> > +	list_splice(&list, &q->timeout_list);
> > +
> >  	spin_unlock_irqrestore(q->queue_lock, flags);
> > 
> >  }
> > -- 
> > 1.5.3.2
> 
> I just noticed that this fix is not upstream yet and i have seen test
> cases hitting this problem.
> 
> Jens, are you going to included this patch, or should this go through
> the SCSI tree?

It's a block patch, so it goes through the block tree ... it also needs
backporting to stable.

James


--
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/