MAC_STUB(4) FreeBSD Kernel Interfaces Manual MAC_STUB(4)


mac_stubMAC policy stub module


To compile the stub policy into your kernel, place the following lines in your kernel configuration file:

options MAC
options MAC_STUB

Alternately, to load the stub module at boot time, place the following line in your kernel configuration file:

options MAC

and in loader.conf(5):



The mac_stub policy module implements a stub MAC policy that has no effect on access control in the system. Unlike mac_none(4), each MAC entry point is defined as a “no-op”, so the policy module will be entered for each event, but no change in system behavior should result.

Label Format

No labels are defined for mac_stub.


The mac_stub policy module first appeared in FreeBSD 5.1 and was developed by the TrustedBSD Project.


This software was contributed to the FreeBSD Project by Network Associates Labs, the Security Research Division of Network Associates Inc. under DARPA/SPAWAR contract N66001-01-C-8035 (“CBOSS”), as part of the DARPA CHATS research program.


See mac(9) concerning appropriateness for production use. The TrustedBSD MAC Framework is considered experimental in FreeBSD.

While the MAC Framework design is intended to support the containment of the root user, not all attack channels are currently protected by entry point checks. As such, MAC Framework policies should not be relied on, in isolation, to protect against a malicious privileged user.

December 1, 2002 FreeBSD