Re: [OOPS] 2.6.11 - NMI lockup with CFQ scheduler

Jens Axboe
2005-04-07T14:47:15Z

On Thu, Apr 07 2005, James Bottomley wrote:
> On Thu, 2005-04-07 at 15:32 +0200, Jens Axboe wrote:
> > I think Christophs point is that why add sdev_lock as a pointer, instead
> > of just killing it? It's only used in one location, so it's not really
> > that confusing (and a comment could fix that).
>
> Because any use of sdev->request_queue->queue_lock would likely succeed
> even after we've freed the device and released the queue. If it's a
> pointer and we null it after free and release, then any later use will
> trigger an immediate NULL deref oops.

So clear ->request_queue instead.

--
Jens Axboe