From: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Subject: [patch] st: fix blk_get_queue usage
Patch-mainline: Submitted to linux-scsi, 1 Aug 2017
References: bnc#834808
If blk_queue_get() in st_probe fails, disk->queue must not
be set to SDp->request_queue, as that would result in
put_disk() dropping a not taken reference.
Thus, disk->queue should be set only after a successful
blk_queue_get().
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Acked-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
---
drivers/scsi/st.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index ff44b3c..dc4826c 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -4111,11 +4111,11 @@ static int st_probe(struct device *dev)
kref_init(&tpnt->kref);
tpnt->disk = disk;
disk->private_data = &tpnt->driver;
- disk->queue = SDp->request_queue;
/* SCSI tape doesn't register this gendisk via add_disk(). Manually
* take queue reference that release_disk() expects. */
- if (!blk_get_queue(disk->queue))
+ if (!blk_get_queue(SDp->request_queue))
goto out_put_disk;
+ disk->queue = SDp->request_queue;
tpnt->driver = &st_template;
tpnt->device = SDp;