In the Linux kernel, the following vulnerability has been resolved:

dm: fix race when loading and unloading a table

If the userspace calls two concurrent table load ioctls and one of them
succeeds and the other fails, there is a race condition because
dm_setup_md_queue walks &md->table_devices without any lock. If the walk
races with dm_table_destroy -> free_devices -> dm_put_table_device, there
is access to invalid memory.

Fix this race by extending the lock over the list walk.