Is it permissible to eat mushrooms that have small, white worms in them, and what is the ruling on the oil in which these mushrooms were cooked, is it permissible to consume it?

According to most scholars, it is permissible to eat food that contains maggots, though it is preferable to clean it. Therefore, there is no harm in eating maggot-ridden mushrooms and the oil in which they were cooked, unless medical evidence proves it to be harmful, in which case it would not be permissible.