So, I've been here racking my brain for the past several days, trying to come up with a good troubleshooting scenario. It turns out that I didn't need to. The Ubuntu folk have handed me a good scenario on a silver platter, in the form of a buggy Samba profile.
As you've just seen, I used aa-enforce to put the two Samba-related profiles into enforce mode. But, watch what happens now when I try to restart Samba in order to get the profiles to take effect:
donnie@ubuntu3:/etc/apparmor.d$ sudo systemctl restart smbdJob for smbd.service failed because the control process exited with error code. See "systemctl status smbd.service" and "journalctl -xe" for details.donnie@ubuntu3:/etc/apparmor.d$
Okay, that's not ...