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.

More... (http://nvd.nist.gov/nvd.cfm?cvename=CVE-2007-5938)