perfmon (perfmon.c) in Linux kernel on IA64 architectures allows local users to cause a denial of service (crash) by interrupting a task while another process is accessing the mm_struct, which triggers a BUG_ON action in the put_page_testzero function.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10177
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=185082
http://www.vupen.com/english/advisories/2006/2554
http://www.vupen.com/english/advisories/2006/1444
http://www.securityfocus.com/bid/17482
http://www.redhat.com/support/errata/RHSA-2007-0774.html
http://www.debian.org/security/2006/dsa-1103
http://secunia.com/advisories/26709
http://secunia.com/advisories/20914