El error en cuestión era parecido a esto:
can't read cwd pst_filedetails: Permission denied
can't read mem pst_filedetails: Permission denied
can't read rtd pst_filedetails: Permission denied
can't read txt pst_filedetails: Permission denied
can't read pst_filedetails: Permission denied
can't read 3 stream structures: Permission denied
can't read pst_socket: Permission denied
En este caso ha sido muy sencillo de solucionar. Simplemente cambiamos los permisos del binario de root y le añadimos setuid a root, es decir, pasamos de 755 a 4755.
El origen en el faq :-), http://www.cs.colostate.edu/~dzubera/FAQs/lsof.faq
