Apple Mac OS X kernel allows local users to cause a denial of service via a process that uses kevent to register a queue and an event, then fork a child process that uses kevent to register an event for the same queue as the parent.
docs.info.apple.com/article.html?artnum=307041
lists.apple.com/archives/security-announce/2007/Nov/msg00002.html
projects.info-pull.com/mokb/MOKB-24-11-2006.html
secunia.com/advisories/23114
secunia.com/advisories/27643
www.osvdb.org/30695
www.securityfocus.com/bid/21285
www.securityfocus.com/bid/26444
www.us-cert.gov/cas/techalerts/TA07-319A.html
www.vupen.com/english/advisories/2006/4715
www.vupen.com/english/advisories/2007/3868
exchange.xforce.ibmcloud.com/vulnerabilities/30544