Integer signedness error in the i386_set_ldt call in FreeBSD 5.5, and possibly earlier versions down to 5.2, allows local users to cause a denial of service (crash) via unspecified arguments that use negative signed integers to cause the bzero function to be called with a large length parameter, a different vulnerability than CVE-2006-4172.
http://www.securityfocus.com/bid/20158
http://www.securityfocus.com/archive/1/446946/100/0/threaded
http://www.idefense.com/intelligence/vulnerabilities/display.php?id=415