The chrp_show_cpuinfo function (chrp/setup.c) in Linux kernel 2.4.21 through 2.6.18-53, when running on PowerPC, might allow local users to cause a denial of service (crash) via unknown vectors that cause the of_get_property function to fail, which triggers a NULL pointer dereference.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11215
https://bugzilla.redhat.com/show_bug.cgi?id=396751
http://www.vupen.com/english/advisories/2008/0380
http://www.ubuntu.com/usn/usn-618-1
http://www.securityfocus.com/bid/27555
http://www.redhat.com/support/errata/RHSA-2008-0154.html
http://www.debian.org/security/2008/dsa-1565
http://www.debian.org/security/2008/dsa-1504
http://www.debian.org/security/2008/dsa-1503
http://secunia.com/advisories/30769
http://secunia.com/advisories/30515
http://secunia.com/advisories/30018
http://secunia.com/advisories/29236
http://secunia.com/advisories/29058
http://secunia.com/advisories/28748
http://secunia.com/advisories/28696