There is one timer which may run whenWhen apruptly detaching a tcp_discardcb() is called,
which is TT_2MSL - to later close the session after a timeout session, stop all timers prior of discarding the tcpcb.
The relative order of the calls to tcp_close() and tcp_discardcb()
is turned around when closing a session via TIME-WAIT.
Reported-by: syzbot+9a9aa434a14a2b35c3ba@syzkaller.appspotmail.com
Reported-by: syzbot+e82856782410e895bae7@syzkaller.appspotmail.com