> Posix(1990) states:
> "For a process to have permission to send a signal to a process designated
> by pid, the real or effective user ID of the sending process must match the
> real or effective user ID of the receiving process, unless the sending
> process has appropriate privileges. If {_POSIX_SAVED_IDS} is defined, the
> saved set-user-ID of the receiving process shall be checked in place of its
> effective user ID."
ISTR this was changed because of a security hole. I'm not so clear if it's
the right way to fix it.
Anyway, the hole I remember is as follows:
System daemon switches identity to user to do something.
User can now send all sorts of signals to daemon.
MfG Kai