patrick@casbs.stanford.edu (Patrick Goebel) (11/21/90)
On our 4/330 running SunOS 4.0.3 I find: % ls -lFg /usr/etc/halt -rwxr-xr-x 1 root staff 81920 Apr 24 1989 halt* Don't these permissions imply that any mortal user could halt the system?! Patrick Goebel--patrick@casbs.Stanford.EDU
barmar@bloom-beacon.mit.edu (Barry Margolin) (11/29/90)
In article <356@brchh104.bnr.ca> patrick@casbs.stanford.edu (Patrick Goebel) writes: >On our 4/330 running SunOS 4.0.3 I find: > >% ls -lFg /usr/etc/halt >-rwxr-xr-x 1 root staff 81920 Apr 24 1989 halt* > >Don't these permissions imply that any mortal user could halt the system?! No. The halt program has to perform a system call to actually reboot the system, and this system call is restricted to the superuser (otherwise any user could write their own halt program). It would be a problem if /usr/etc/halt were *setuid* to root, e.g. if the permission were -rwsr-xr-x. Barry Margolin, Thinking Machines Corp. barmar@think.com {uunet,harvard}!think!barmar