Macheda's current deal runs to June.
"You'd have to ask Ferguson about that, as he's the one who makes the decisions," said Macheda.
"I don't know if that would be possible, but you never know what could happen in life. I do really like it here."
The 19-year-old arrived as a replacement for Antonio Cassano, who joined Milan following a contract dispute.
"Cassano is one of the best players I have ever seen. His technical skills are just fantastic."