The add_del_listener function in kernel/taskstats.c in the Linux kernel 2.6.39.1 and earlier does not prevent multiple registrations of exit handlers, which allows local users to cause a denial of service (memory and CPU consumption), and bypass the OOM Killer, via a crafted application.
http://openwall.com/lists/oss-security/2011/06/22/1
http://openwall.com/lists/oss-security/2011/06/22/2