The do_mmap_pgoff function in mm/nommu.c in the Linux kernel before 2.6.31.6, when the CPU lacks a memory management unit, allows local users to cause a denial of service (OOPS) via an application that attempts to allocate a large amount of memory.
http://www.ubuntu.com/usn/usn-864-1
http://www.openwall.com/lists/oss-security/2009/11/13/3
http://www.openwall.com/lists/oss-security/2009/11/09/2
http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.31.6