nilfs2: fix NULL pointer dereference at nilfs_bmap_lookup_at_level()
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 v4.19.262 by commit fe8015680f383ea1dadec76972894dfabf8aefaa. For more details please see the references link.