CVE-2021-46923

In the Linux kernel, the following vulnerability has been resolved:
fs/mount_setattr: always cleanup mount_kattr Make sure that
finish_mount_kattr() is called after mount_kattr was succesfully built in
both the success and failure case to prevent leaking any references we took
when we built it. We returned early if path lookup failed thereby risking
to leak an additional reference we took when building mount_kattr when an
idmapped mount was requested.