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. References: https://source.android.com/security/bulletin/2017-08-01#kernel-components https://sourceforge.net/p/linux-f2fs/mailman/message/35835945/ Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=15d3042a937c13f5d9244241c7a9c8416ff6e82a
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1481153]
Statement: 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