A security flaw was discovered in the Linux kernel. The vmacache_flush_all() function in mm/vmacache.c mishandles sequence number overflows. An attacker can trigger a use-after-free (and possibly gain privileges) via certain thread creation, map, unmap, invalidation, and dereference operations.
An upstream patch:
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1631206]
This issue has been addressed in the following products:
Red Hat Enterprise Linux 7
Via RHSA-2018:3656 https://access.redhat.com/errata/RHSA-2018:3656