From: Tejun Heo <tj@kernel.org>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Mike Christie <michaelc@cs.wisc.edu>,
linux-scsi <linux-scsi@vger.kernel.org>,
James Bottomley <jbottomley@parallels.com>,
Jens Axboe <axboe@kernel.dk>, Chanho Min <chanho.min@lge.com>
Subject: Re: [PATCH] Fix a use-after-free triggered by device removal
Date: Mon, 10 Sep 2012 16:38:43 -0700 [thread overview]
Message-ID: <20120910233843.GI7677@google.com> (raw)
In-Reply-To: <50499AC6.1050008@acm.org>
Hello,
On Fri, Sep 07, 2012 at 08:57:10AM +0200, Bart Van Assche wrote:
> I'm not sure it would be a good idea to add a blk_queue_dead() check in
> any of the __blk_run_queue() variants since blk_drain_queue() can invoke
> __blk_run_queue() to drain the queue.
Right, we can't cancel requests from block layer which were already
seen by the driver.
> Also, as far as I can see the functions that can insert a request into
> the queue (blk_insert_cloned_request(), queue_unplugged(),
> blk_execute_rq_nowait()) all check whether the queue is dead before
> inserting a request. That should be sufficient to prevent that new
> requests are queued after QUEUE_FLAG_DEAD has been set.
Yes, but does that guarantee that none would call into ->request_fn()?
If so, fine; otherwise, we may need to add another state to prevent
that.
Thanks.
--
tejun
next prev parent reply other threads:[~2012-09-10 23:38 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-03 14:12 [PATCH] Fix a use-after-free triggered by device removal Bart Van Assche
2012-09-06 16:27 ` Michael Christie
2012-09-06 17:58 ` Bart Van Assche
2012-09-06 18:14 ` Mike Christie
2012-09-06 18:52 ` Bart Van Assche
2012-09-06 23:20 ` Tejun Heo
2012-09-07 6:57 ` Bart Van Assche
2012-09-10 23:38 ` Tejun Heo [this message]
2012-09-11 6:42 ` Bart Van Assche
2012-09-12 20:53 ` Tejun Heo
2012-09-13 7:26 ` Bart Van Assche
2012-09-13 16:53 ` Tejun Heo
2012-09-13 18:27 ` Bart Van Assche
2012-09-13 19:25 ` Tejun Heo
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