Memory leak in the __key_link_end function in security/keys/keyring.c in the Linux kernel before 4.1.4 allows local users to cause a denial of service (memory consumption) via many add_key system calls that refer to existing keys.
https://support.f5.com/csp/article/K05211147
https://github.com/torvalds/linux/commit/ca4da5dd1f99fe9c59f1709fb43e818b18ad20e0
https://bugzilla.redhat.com/show_bug.cgi?id=1245658
http://www.ubuntu.com/usn/USN-2691-1
http://www.ubuntu.com/usn/USN-2690-1
http://www.ubuntu.com/usn/USN-2689-1
http://www.ubuntu.com/usn/USN-2688-1
http://www.ubuntu.com/usn/USN-2687-1
http://www.securityfocus.com/bid/76050
http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
http://www.openwall.com/lists/oss-security/2015/07/27/7
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.1.4
http://www.debian.org/security/2015/dsa-3329
http://rhn.redhat.com/errata/RHSA-2015-1787.html