The i915 driver in (1) drivers/char/drm/i915_dma.c in the Linux kernel 2.6.24 on Debian GNU/Linux and (2) sys/dev/pci/drm/i915_drv.c in OpenBSD does not restrict the DRM_I915_HWS_ADDR ioctl to the Direct Rendering Manager (DRM) master, which allows local users to cause a denial of service (memory corruption) via a crafted ioctl call, related to absence of the DRM_MASTER and DRM_ROOT_ONLY flags in the ioctl's configuration.
https://www.redhat.com/archives/fedora-package-announce/2008-October/msg00693.html
https://www.redhat.com/archives/fedora-package-announce/2008-October/msg00689.html
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11542
http://www.ubuntu.com/usn/usn-679-1
http://www.ubuntu.com/usn/usn-659-1
http://www.securityfocus.com/bid/31792
http://www.securityfocus.com/archive/1/498285/100/0/threaded
http://www.redhat.com/support/errata/RHSA-2009-0009.html
http://www.redhat.com/support/errata/RHSA-2008-1017.html
http://www.openbsd.org/cgi-bin/cvsweb/src/sys/dev/pci/drm/i915_drv.c.diff?r1=1.7%3Br2=1.8
http://www.openbsd.org/cgi-bin/cvsweb/src/sys/dev/pci/drm/i915_drv.c
http://www.mandriva.com/security/advisories?name=MDVSA-2008:224
http://www.debian.org/security/2008/dsa-1655
http://wiki.rpath.com/wiki/Advisories:rPSA-2008-0316
http://wiki.rpath.com/Advisories:rPSA-2008-0316
http://sunsolve.sun.com/search/document.do?assetkey=1-26-245846-1
http://securitytracker.com/id?1021065
http://secunia.com/advisories/33586
http://secunia.com/advisories/33182
http://secunia.com/advisories/32918
http://secunia.com/advisories/32709
http://secunia.com/advisories/32386
http://secunia.com/advisories/32315
http://archives.neohapsis.com/archives/openbsd/cvs/2008-10/0365.html