Race condition in the key_gc_unused_keys function in security/keys/gc.c in the Linux kernel through 3.18.2 allows local users to cause a denial of service (memory corruption or panic) or possibly have unspecified other impact via keyctl commands that trigger access to a key structure member during garbage collection of a key.
https://github.com/torvalds/linux/commit/a3a8784454692dd72e5d5d34dcdab17b4420e74c
https://exchange.xforce.ibmcloud.com/vulnerabilities/99641
https://bugzilla.redhat.com/show_bug.cgi?id=1179813
http://www.ubuntu.com/usn/USN-2518-1
http://www.ubuntu.com/usn/USN-2517-1
http://www.ubuntu.com/usn/USN-2516-1
http://www.ubuntu.com/usn/USN-2515-1
http://www.ubuntu.com/usn/USN-2514-1
http://www.ubuntu.com/usn/USN-2513-1
http://www.ubuntu.com/usn/USN-2512-1
http://www.ubuntu.com/usn/USN-2511-1
http://www.securitytracker.com/id/1036763
http://www.securityfocus.com/bid/71880
http://www.openwall.com/lists/oss-security/2015/01/06/10
http://www.mandriva.com/security/advisories?name=MDVSA-2015:058
http://www.debian.org/security/2015/dsa-3128
http://rhn.redhat.com/errata/RHSA-2015-1138.html
http://rhn.redhat.com/errata/RHSA-2015-1137.html
http://rhn.redhat.com/errata/RHSA-2015-0864.html
http://lists.opensuse.org/opensuse-security-announce/2015-04/msg00009.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-January/147973.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-January/147864.html