OOM when reading tag from fuzzed file

[5225225]

Reproduction code

fn main() {
    let data = [0, 0, 0, 1, 102, 116, 121, 112, 0, 132, 255, 255, 255, 255, 0, 132];
    let mut data = std::io::Cursor::new(data);
    let tag = mp4ameta::Tag::read_from(&mut data);
}

Results in

memory allocation of 37436171902451828 bytes failed
zsh: abort (core dumped)  cargo run

[saecki]

Oh, there should be some sort of sanity check.