The user_update function in security/keys/user_defined.c in the Linux kernel 2.6 allows local users to cause a denial of service (NULL pointer dereference and kernel oops) via vectors related to a user-defined key and "updating a negative key into a fully instantiated key."
Category : Permissions, Privileges, and Access Controls Weaknesses in this category are related to the management of permissions, privileges, and other security features that are used to perform access control.