From: Bart Van Assche <bvanassche@acm.org>
To: Chanho Min <chanho0207@gmail.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>,
James Bottomley <JBottomley@parallels.com>,
linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
Jens Axboe <axboe@kernel.dk>, Tejun Heo <tj@kernel.org>
Subject: Re: [PATCH] fix NULL-pointer dereference on scsi_run_queue
Date: Tue, 07 Aug 2012 09:43:16 +0000 [thread overview]
Message-ID: <5020E334.4070809@acm.org> (raw)
In-Reply-To: <CAOAMb1BWWzYPSode-6Y9+O5eNhMc-bYofCNwMRmzeC9-nhRb4g@mail.gmail.com>
On 08/07/12 08:53, Chanho Min wrote:
> In addition, Is it ironic that we are careful to use put_device at
> scsi_request_fn?. If we trigger the ->remove(),
> It occur a oops. What about the removal of unlock/lock as patch bellow?
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index 4037fd5..8d9eccd 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -1608,11 +1608,7 @@ out_delay:
> if (sdev->device_busy == 0)
> blk_delay_queue(q, SCSI_QUEUE_DELAY);
> out:
> - /* must be careful here...if we trigger the ->remove() function
> - * we cannot be holding the q lock */
> - spin_unlock_irq(q->queue_lock);
> put_device(&sdev->sdev_gendev);
> - spin_lock_irq(q->queue_lock);
> }
As far as I can see the comment in the above code was added before
scsi_device_dev_release() was moved to user context, so it might be
outdated. See also
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=65110b2168950a19cc78b5027ed18cb811fbdae8.
Bart.
next prev parent reply other threads:[~2012-08-07 9:43 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-02 8:41 [PATCH] fix NULL-pointer dereference on scsi_run_queue Chanho Min
2012-08-02 8:57 ` James Bottomley
2012-08-02 9:28 ` Chanho Min
2012-08-02 9:34 ` James Bottomley
2012-08-03 2:28 ` Chanho Min
2012-08-03 3:01 ` Mike Christie
2012-08-04 9:01 ` Bart Van Assche
2012-08-04 16:46 ` Mike Christie
2012-08-04 20:18 ` Bart Van Assche
2012-08-04 22:36 ` Mike Christie
2012-08-06 17:56 ` Bart Van Assche
2012-08-07 8:53 ` Chanho Min
2012-08-07 9:30 ` Bart Van Assche
2012-08-08 3:42 ` Chanho Min
2012-08-08 7:37 ` Bart Van Assche
2012-08-07 9:43 ` Bart Van Assche [this message]
2012-08-07 16:16 ` Mike Christie
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