userfaultfd: release page in error path to avoid BUG_ON
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v4.19.191 by commit 07c9b834c97d0fa3402fb7f3f3b32df370a6ff1f, it was introduced in version v4.11 by commit cb658a453b9327ce96ce5222c24d162b5b65b564. For more details please see the references link.