Ok, percebi isso.
Estes são os comandos para dar a um diretório ou arquivo as permissões:
chmod 400 mydoc.txt read by owner
chmod 040 mydoc.txt read by group
chmod 004 mydoc.txt read by anybody (other)
chmod 200 mydoc.txt write by owner
chmod 020 mydoc.txt write by group
chmod 002 mydoc.txt write by anybody
chmod 100 mydoc.txt execute by owner
chmod 010 mydoc.txt execute by group
chmod 001 mydoc.txt execute by anybody
e usei isso para me dar todas as permissões:
sudo chown -R loko:sudo /home