From 67bd94130015c507011af37858989b199c52e1de Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 29 Jun 2012 15:33:22 +0000 Subject: [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 Signed-off-by: Bart Van Assche Reviewed-by: Mike Christie Reviewed-by: Tejun Heo Cc: Signed-off-by: James Bottomley --- drivers/scsi/scsi_sysfs.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'drivers/scsi/scsi_sysfs.c') diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 5747478..9aa578a 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -972,11 +972,8 @@ void __scsi_remove_device(struct scsi_device *sdev) sdev->host->hostt->slave_destroy(sdev); transport_destroy_device(dev); - /* cause the request function to reject all I/O requests */ - sdev->request_queue->queuedata = NULL; - /* Freeing the queue signals to block that we're done */ - scsi_free_queue(sdev->request_queue); + blk_cleanup_queue(sdev->request_queue); put_device(dev); } -- cgit v1.1