The BPF subsystem in the Linux kernel before 4.5.5 mishandles reference counts, which allows local users to cause a denial of service (use-after-free) or possibly have unspecified other impact via a crafted application on (1) a system with more than 32 Gb of memory, related to the program reference count or (2) a 1 Tb system, related to the map reference count.
https://github.com/torvalds/linux/commit/92117d8443bc5afacc8d5ba82e541946310f106e
https://bugzilla.redhat.com/show_bug.cgi?id=1334303
http://www.ubuntu.com/usn/USN-3007-1
http://www.ubuntu.com/usn/USN-3006-1
http://www.ubuntu.com/usn/USN-3005-1
http://www.openwall.com/lists/oss-security/2016/05/06/4