Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!gatech!bloom-beacon!simsong From: simsong@athena.mit.edu (Simson L. Garfinkel) Newsgroups: comp.os.minix Subject: Re: super_user in fs Message-ID: <1142@bloom-beacon.MIT.EDU> Date: Wed, 15-Jul-87 12:58:57 EDT Article-I.D.: bloom-be.1142 Posted: Wed Jul 15 12:58:57 1987 Date-Received: Fri, 17-Jul-87 06:09:34 EDT References: <462@csm9a.UUCP> <613@uokmax.UUCP> Sender: daemon@bloom-beacon.MIT.EDU Reply-To: simsong@athena.mit.edu (Simson L. Garfinkel) Organization: MIT Project Athena Lines: 9 In article <613@uokmax.UUCP> rmtodd@uokmax.UUCP (Richard Michael Todd) writes: >The trick is (in my opinion) one of the cleverest features of UNIX: the >set-uid mode bit. If you have a program which has this mode bit set and >is owned by root, whenever that program is run it can do any system call >that root can-- its "effective uid" is set to root. This way system calls I would like to point out that Bell Labs has a patent on the setuid bit. ................................................................simson