Chet, an aspiring rapper, opened up about his battle with addiction on an Instagram post.
"As a parent, you love your kids unconditionally," 59-year-old Tom told Entertainment Tonight.
"You support them in every step of the way. You got to applaud the bravery and honesty when it actually comes out of your own house," said Hanks.
Chet, 26, said having a famous father made it difficult for him to find a place where he could fit in.