Linux kernel 2.4.x and 2.6.x for x86 allows local users to cause a denial of service (system crash), possibly via an infinite loop that triggers a signal handler with a certain sequence of fsave and frstor instructions, as originally demonstrated using a "crash.c" program.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9426
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A2915
https://exchange.xforce.ibmcloud.com/vulnerabilities/16412
http://www.trustix.net/errata/2004/0034/
http://www.securityfocus.com/bid/10538
http://www.redhat.com/support/errata/RHSA-2004-260.html
http://www.redhat.com/support/errata/RHSA-2004-255.html
http://www.novell.com/linux/security/advisories/2004_17_kernel.html
http://www.mandriva.com/security/advisories?name=MDKSA-2004:062
http://www.kb.cert.org/vuls/id/973654
http://www.debian.org/security/2006/dsa-1082
http://www.debian.org/security/2006/dsa-1070
http://www.debian.org/security/2006/dsa-1069
http://www.debian.org/security/2006/dsa-1067
http://security.gentoo.org/glsa/glsa-200407-02.xml
http://secunia.com/advisories/20338
http://secunia.com/advisories/20202
http://secunia.com/advisories/20163
http://secunia.com/advisories/20162
http://marc.info/?l=linux-kernel&m=108681568931323&w=2
http://marc.info/?l=bugtraq&m=108793699910896&w=2
http://marc.info/?l=bugtraq&m=108786114032681&w=2
http://lwn.net/Articles/91155/
http://linuxreviews.org/news/2004-06-11_kernel_crash/index.html
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15905
http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000845