An issue was discovered in the Linux kernel through 4.17.10. There is an out-of-bounds access in __remove_dirty_segment() in fs/f2fs/segment.c when mounting an f2fs image.
https://usn.ubuntu.com/4118-1/
https://usn.ubuntu.com/4094-1/
https://usn.ubuntu.com/3932-2/
https://usn.ubuntu.com/3932-1/
https://lists.debian.org/debian-lts-announce/2019/03/msg00017.html