This gives a false sense of security, since the most common use-after-free bugs are if you kept a pointer around. Your method doesn't stop things like this:

    void *p1, *p2;
    malloc(100, &p1);
    p2 = p1;
    ...
    free(&p1);
    *p2; // oops!

Obviously its trivial in an example like this, but when p2 leaves the lexical scope then there's a problem.