The Linux kernel 2.4.20 and earlier, and 2.5.x, when running on x86 systems, allows local users to cause a denial of service (hang) via the emulation mode, which does not properly clear TF and NT EFLAGs.
https://exchange.xforce.ibmcloud.com/vulnerabilities/10576
http://www.securityfocus.com/bid/6115
http://www.redhat.com/support/errata/RHSA-2002-263.html
http://rhn.redhat.com/errata/RHSA-2002-264.html
http://rhn.redhat.com/errata/RHSA-2002-262.html
http://marc.info/?l=bugtraq&m=103737292709297&w=2
http://marc.info/?l=bugtraq&m=103714004623587&w=2
http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000553