nbd: fix nbd device deletion

This fixes a use after free bug, we shouldn't be doing disk->queue right
after we do del_gendisk(disk).  Save the queue and do the cleanup after
the del_gendisk.

Fixes: c6a4759ea0 ("nbd: add device refcounting")
cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Josef Bacik 2018-05-16 14:51:17 -04:00 committed by Jens Axboe
parent 3de9beeeb4
commit 8364da4751

View File

@ -173,9 +173,12 @@ static const struct device_attribute pid_attr = {
static void nbd_dev_remove(struct nbd_device *nbd)
{
struct gendisk *disk = nbd->disk;
struct request_queue *q;
if (disk) {
q = disk->queue;
del_gendisk(disk);
blk_cleanup_queue(disk->queue);
blk_cleanup_queue(q);
blk_mq_free_tag_set(&nbd->tag_set);
disk->private_data = NULL;
put_disk(disk);