A missing authorization check in the fscrypt_process_policy function in fs/crypto/policy.c in the ext4 and f2fs filesystem encryption support in the Linux kernel before 4.7.4 allows a user to assign an encryption policy to a directory owned by a different user, potentially creating a denial of service.
https://github.com/torvalds/linux/commit/163ae1c6ad6299b19e22b4a35d5ab24a89791a98
http://www.securityfocus.com/bid/97404