The KEYS subsystem in the Linux kernel before 4.13.10 does not correctly synchronize the actions of updating versus finding a key in the "negative" state to avoid a race condition, which allows local users to cause a denial of service or possibly have unspecified other impact via crafted system calls.
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1514003]
This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6, 7 and MRG 2 as a code with the flaw is not present in the products listed.
This was fixed for Fedora with the 4.13.10 stable updates.