Encontrou aqui
Q) Can I restrict users to their home directories? A) Yes. You are probably after the setting: chroot_local_user=YES
Mas uma solução mais segura está registrada abaixo.
Q) Why don't symlinks work with chroot_local_user=YES? A) This is a consequence of how chroot() security works. As alternatives, look into hard links, or if you have a modern Linux, see the powerful "mount --bind".