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author | Bart Van Assche <bvanassche@acm.org> | 2012-06-29 15:33:22 +0000 |
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committer | James Bottomley <JBottomley@Parallels.com> | 2012-07-20 08:58:40 +0100 |
commit | 67bd94130015c507011af37858989b199c52e1de (patch) | |
tree | 9b4bc8ef5c7180d920eae0f95158dc377c38df8c /drivers/scsi/hosts.c | |
parent | e81ca6fe85b77109a32489a5db82f575d51dfc98 (diff) | |
download | linux-67bd94130015c507011af37858989b199c52e1de.tar.gz linux-67bd94130015c507011af37858989b199c52e1de.tar.bz2 linux-67bd94130015c507011af37858989b199c52e1de.zip |
[SCSI] Fix device removal NULL pointer dereference
Use blk_queue_dead() to test whether the queue is dead instead
of !sdev. Since scsi_prep_fn() may be invoked concurrently with
__scsi_remove_device(), keep the queuedata (sdev) pointer in
__scsi_remove_device(). This patch fixes a kernel oops that
can be triggered by USB device removal. See also
http://www.spinics.net/lists/linux-scsi/msg56254.html.
Other changes included in this patch:
- Swap the blk_cleanup_queue() and kfree() calls in
scsi_host_dev_release() to make that code easier to grasp.
- Remove the queue dead check from scsi_run_queue() since the
queue state can change anyway at any point in that function
where the queue lock is not held.
- Remove the queue dead check from the start of scsi_request_fn()
since it is redundant with the scsi_device_online() check.
Reported-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Tejun Heo <tj@kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/hosts.c')
-rw-r--r-- | drivers/scsi/hosts.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 2b6a03de5787..593085a52275 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -290,6 +290,7 @@ static void scsi_host_dev_release(struct device *dev) struct Scsi_Host *shost = dev_to_shost(dev); struct device *parent = dev->parent; struct request_queue *q; + void *queuedata; scsi_proc_hostdir_rm(shost->hostt); @@ -299,9 +300,9 @@ static void scsi_host_dev_release(struct device *dev) destroy_workqueue(shost->work_q); q = shost->uspace_req_q; if (q) { - kfree(q->queuedata); - q->queuedata = NULL; - scsi_free_queue(q); + queuedata = q->queuedata; + blk_cleanup_queue(q); + kfree(queuedata); } scsi_destroy_command_freelist(shost); |