A slightly shorter form:

    /\*(?:(?!\*/).)*\*/

Basically it's:

    match start

    while not match end:
        consume character

    match end

If the "match end" is a single character, you can use a negated character set, for example:

    [^\n]*

otherwise you need a negative lookahead, for example:

    (?:(?!\r\n).)*