The sanity_check_ckpt function in fs/f2fs/super.c in the Linux kernel before 4.12.4 does not validate the blkoff and segno arrays, which allows an unprivileged local user to cause a system panic and DoS. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although we believe it is unlikely.
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1481153]
This issue does not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 5, 6, 7 and Red Hat Enterprise MRG 2 as the code with the flaw is not built and shipped with the products listed.
This was fixed for Fedora with the 4.12.4 stable updates