dm: fix a crash if blk_alloc_disk fails

If blk_alloc_disk fails, the variable md->disk is set to an error value.
cleanup_mapped_device will see that md->disk is non-NULL and it will
attempt to access it, causing a crash on this statement
"md->disk->private_data = NULL;".

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reported-by: Chenyuan Yang <chenyuan0y@gmail.com>
Closes: https://marc.info/?l=dm-devel&m=172824125004329&w=2
Cc: stable@vger.kernel.org
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
This commit is contained in:
Mikulas Patocka 2024-10-07 13:38:12 +02:00
parent 8e929cb546
commit fed13a5478

View File

@ -2290,8 +2290,10 @@ static struct mapped_device *alloc_dev(int minor)
* override accordingly. * override accordingly.
*/ */
md->disk = blk_alloc_disk(NULL, md->numa_node_id); md->disk = blk_alloc_disk(NULL, md->numa_node_id);
if (IS_ERR(md->disk)) if (IS_ERR(md->disk)) {
md->disk = NULL;
goto bad; goto bad;
}
md->queue = md->disk->queue; md->queue = md->disk->queue;
init_waitqueue_head(&md->wait); init_waitqueue_head(&md->wait);