The online_pages function in mm/memory_hotplug.c in the Linux kernel before 3.6 allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact in opportunistic circumstances by using memory that was hot-added by an administrator.
https://www.suse.com/support/update/announcement/2012/suse-su-20121679-1.html
https://github.com/torvalds/linux/commit/08dff7b7d629807dbb1f398c68dd9cd58dd657a1
https://bugzilla.redhat.com/show_bug.cgi?id=875374
http://www.ubuntu.com/usn/USN-1679-1
http://www.ubuntu.com/usn/USN-1678-1
http://www.ubuntu.com/usn/USN-1677-1
http://www.ubuntu.com/usn/USN-1673-1
http://www.ubuntu.com/usn/USN-1671-1
http://www.securityfocus.com/bid/56527
http://www.openwall.com/lists/oss-security/2012/11/13/11
http://www.kernel.org/pub/linux/kernel/v3.x/patch-3.6.bz2
http://www.kernel.org/pub/linux/kernel/v3.x/
http://rhn.redhat.com/errata/RHSA-2012-1580.html
http://lists.opensuse.org/opensuse-security-announce/2013-06/msg00005.html