Mastering Linux Security and Hardening - Second Edition

Hands-on lab – Troubleshooting an AppArmor profile

Perform this lab on your Ubuntu 18.04 VM. Carry out the following steps for troubleshooting:

1. Install the AppArmor utilities and the extra profiles:

sudo apt install apparmor-utils apparmor-profiles apparmor-profiles-extra

2. Install Samba and verify that it's running:

sudo apt install sambasudo systemctl status smbdsudo systemctl status nmbd

3. Set the two aforementioned Samba policies to enforce mode and try to restart Samba:

cd /etc/apparmor.dsudo aa-enforce /usr/sbin/smbd usr.sbin.smbdsudo aa-enforce /usr/sbin/nmbd usr.sbin.nmbdsudo systemctl restart smbd

Note that Samba should fail to restart. (It will take quite a while before it finally errors out, so be patient.)

4. Look in the /var/log/syslog ...