The key_replace_session_keyring function in security/keys/process_keys.c in the Linux kernel before 2.6.39.1 does not initialize a certain structure member, which allows local users to cause a denial of service (NULL pointer dereference and OOPS) or possibly have unspecified other impact via a KEYCTL_SESSION_TO_PARENT argument to the keyctl function, a different vulnerability than CVE-2010-2960.