[PATCH 4.15 181/202] pktcdvd: Fix pkt_setup_dev() error path

From: Greg Kroah-Hartman
Date: Thu Feb 15 2018 - 11:01:11 EST


4.15-stable review patch. If anyone has any objections, please let me know.

------------------

From: Bart Van Assche <bart.vanassche@xxxxxxx>

commit 5a0ec388ef0f6e33841aeb810d7fa23f049ec4cd upstream.

Commit 523e1d399ce0 ("block: make gendisk hold a reference to its queue")
modified add_disk() and disk_release() but did not update any of the
error paths that trigger a put_disk() call after disk->queue has been
assigned. That introduced the following behavior in the pktcdvd driver
if pkt_new_dev() fails:

Kernel BUG at 00000000e98fd882 [verbose debug info unavailable]

Since disk_release() calls blk_put_queue() anyway if disk->queue != NULL,
fix this by removing the blk_cleanup_queue() call from the pkt_setup_dev()
error path.

Fixes: commit 523e1d399ce0 ("block: make gendisk hold a reference to its queue")
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Maciej S. Szmigiero <mail@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/block/pktcdvd.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2745,7 +2745,7 @@ static int pkt_setup_dev(dev_t dev, dev_
pd->pkt_dev = MKDEV(pktdev_major, idx);
ret = pkt_new_dev(pd, dev);
if (ret)
- goto out_new_dev;
+ goto out_mem2;

/* inherit events of the host device */
disk->events = pd->bdev->bd_disk->events;
@@ -2763,8 +2763,6 @@ static int pkt_setup_dev(dev_t dev, dev_
mutex_unlock(&ctl_mutex);
return 0;

-out_new_dev:
- blk_cleanup_queue(disk->queue);
out_mem2:
put_disk(disk);
out_mem: