In combination with the apparmor package, the Ubuntu kernel now restricts the use of unprivileged user namespaces. This affects all programs on the system that are unprivileged and unconfined. A default AppArmor profile is provided that allows the use of user namespaces for unprivileged and unconfined applications but will deny the subsequent use of any capabilities within the user namespace. A common use-case for unprivileged user namespaces is applications that construct their own sandboxes or work with styles of container workloads. As such, AppArmor profiles that allow the use of unprivileged user namespaces are also provided for common applications and frameworks that come from the Ubuntu archive, as well as popular third party applications like Google Chrome, Discord and others. This is a subsequent step towards trying to mitigate the larger attack surface presented by unprivileged user namespaces (the first being the introduction of this feature in Ubuntu 23.10 where it was not enabled by default).