The file watch implementation in the audit subsystem (auditctl -w) in the Red Hat Enterprise Linux (RHEL) 4 kernel 2.6.9 allows local users to cause a denial of service (kernel panic) by replacing a watched file, which does not cause the watch on the old inode to be dropped.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9560
http://www.securitytracker.com/id?1017705
http://www.securityfocus.com/bid/22737
http://www.redhat.com/support/errata/RHSA-2007-0085.html