The iwl_set_rate function in compatible/iwl3945-base.c in iwlwifi 1.1.21 and earlier dereferences an iwl_get_hw_mode return value without checking for NULL, which might allow remote attackers to cause a denial of service (kernel panic) via unspecified vectors during module initialization.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10787
http://www.vupen.com/english/advisories/2007/4211
http://www.securityfocus.com/bid/26842
http://www.redhat.com/support/errata/RHSA-2008-0154.html
http://secunia.com/advisories/29236
http://article.gmane.org/gmane.linux.drivers.ipw3945.devel/1618