Subject: Re: clearing suid/sgid bits upon ownership change
To: Jim Wise <jimw@numenor.turner.com>
From: Rob Windsor <windsor@warthog.com>
List: tech-kern
Date: 12/10/1997 14:30:26
Verily did Jim Wise write:
> -----BEGIN PGP SIGNED MESSAGE-----
>
> On Tue, 9 Dec 1997, Rob Windsor wrote:
>
> > securelevel >1. I can't stand this behavior. No other modern un*x in the
> > world does this insane crap. I just love `surprises' like this in NetBSD -
>-
> > not.
>
> - From the XSI5 (Unix 98) Standard:
>
> If the path argument refers to a regular file, the set-user-ID
> (S_ISUID) and set-group-ID (S_ISGID) bits of the file mode are
> cleared upon successful return from chown(), unless the call is
> made by a process with appropriate privileges, in which case it
> is implementation-dependent whether these bits are altered.
>
> It is also not true that ` No other modern un*x in the world does this':
Try it as root (as I had clarified in my e-mail this morning).
> Solaris 2.6:
> $ touch foo
> $ ls -l foo
> - -rw-r--r-- 1 jim users 0 Dec 10 11:58 foo
> $ chmod 6555 foo
> $ ls -l foo
> - -r-sr-sr-x 1 jim users 0 Dec 10 11:58 foo
> $ chgrp src foo
> $ ls -l foo
> - -r-xr-xr-x 1 jim src 0 Dec 10 11:58 foo
> Irix 6.2
>
> $ touch foo
> $ ls -l foo
> - -rw-r--r-- 1 jimw graphics 0 Dec 10 11:54 foo
> $ chmod 6555 foo
> $ ls -l foo
> - -r-sr-sr-x 1 jimw graphics 0 Dec 10 11:54 foo
> $ chgrp wits foo
> $ ls -l foo
> - -r-xr-xr-x 1 jimw wits 0 Dec 10 11:54 foo
>
> So, this feature may or may not be a good idea, (I like it myself), but
> it _is_ standard, and it _is_ widely implemented.
But, again, not as root.
-- Rob
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