The __get_data_block function in fs/f2fs/data.c in the Linux kernel before 4.11 allows local users to cause a denial of service (integer overflow and loop) via crafted use of the open and fallocate system calls with an FS_IOC_FIEMAP ioctl.
https://www.debian.org/security/2018/dsa-4188
https://usn.ubuntu.com/3696-2/
https://usn.ubuntu.com/3696-1/
https://github.com/torvalds/linux/commit/b86e33075ed1909d8002745b56ecf73b833db143