I have been doing Xenial -> Bionic -> Focal release upgrades and started running into this apparmor issue with dhclient after reaching Focal.
I don't know the root issue, and it doesn't appear to impact functionality (at least as far as I can tell on my hosts). However, I am currently dealing with this by adding the following to /etc/apparmor.d/local/sbin.dhclient: @{PROC}/[0-9]*/task/[0-9]*/comm rw, -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1918410 Title: isc-dhcp-client denied by apparmor To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/1918410/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs