Commit c055f5b2 authored May 01, 2011 by James Bottomley

[SCSI] fix oops in scsi_run_queue()



The recent commit closing the race window in device teardown:

commit 86cbfb56
Author: James Bottomley <James.Bottomley@suse.de>
Date:   Fri Apr 22 10:39:59 2011 -0500

    [SCSI] put stricter guards on queue dead checks

is causing a potential NULL deref in scsi_run_queue() because the
q->queuedata may already be NULL by the time this function is called.
Since we shouldn't be running a queue that is being torn down, simply
add a NULL check in scsi_run_queue() to forestall this.

Tested-by: Jim Schutt <jaschut@sandia.gov>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

parent 3fd9952d

drivers/scsi/scsi_lib.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -400,10 +400,15 @@ static inline int scsi_host_is_busy(struct Scsi_Host *shost)
		static void scsi_run_queue(struct request_queue *q)
		{
		struct scsi_device *sdev = q->queuedata;
		struct Scsi_Host *shost = sdev->host;
		struct Scsi_Host *shost;
		LIST_HEAD(starved_list);
		unsigned long flags;

		/* if the device is dead, sdev will be NULL, so no queue to run */
		if (!sdev)
		return;

		shost = sdev->host;
		if (scsi_target(sdev)->single_lun)
		scsi_single_lun_run(sdev);