I always wonder if there is any good solution for I/O blocking on local exploit.
I tried sock.setblocking(False) and fcntl(fd, F_SETFL, flag | O_NONBLOCK), but both didn’t work.
pexpect module does non-blocking read(maybe it’s because of tty), but its output contains junk and input becomes corrupted(doesn’t support binary data?).
So please tell me if you know something.

exploit(consequently I did without reading): https://gist.github.com/potetisensei/9af8150d66031035cc10