From: clemc@ccc.com (Clem Cole)
Subject: [TUHS] History of chown semantics
Date: Thu, 9 Jan 2014 14:51:12 -0500 [thread overview]
Message-ID: <CAC20D2PrPwKe3KDBbU0v6GcXWM+2PEUyTwzu6ZWZMB-mivobyQ@mail.gmail.com> (raw)
In-Reply-To: <201401091923.s09JNVRw003234@cuzuco.com>
On Thu, Jan 9, 2014 at 2:23 PM, Brian S Walden <tuhs at cuzuco.com> wrote:
> non-su chown worked in pwb, if the caller owned the file. code had to be
> added then to the system call to strip the setuid/setgid bits if you were
> not su, for obvious security reasons. you didnt see that bit stripping
> in, say the v6/v7 code.
Brian - right as I showed in the code snippet from V6 and PWB. The idea
came into being with PWB.
The question that is still open is why was it added/need in the first
place? I always thought is was a crazy/miss feature,
I think the argument is that if you owned the file, you should be allowed
to give it to anyone else [including root] - but that actions opens up a
number of issues (you pointed the big security one that was handled by
and-ing off the SUID/SGID bits). There are accounting issues as well as
the practical one that Tim and I pointed out with importing of files on a
tape.
As I said, the file give-away feature comes into UNIX with PWB, so I would
ask Mash is he remembers why it was needed and why the SVID folks wanted
it. As I said, I personally found it not useful/a bad idea/miss-feature.
I remember that I soon after I learned about it/got bitten by the side
effect, I ran into dmr and srb at a USENIX and asked them about that a few
other System III features that I found a little strange. I don't remember
much of the conversation. But, if there are been a "good" reason I think
I would have remembered it and not always thought it to be a bad idea.
Clem
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next prev parent reply other threads:[~2014-01-09 19:51 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-09 19:23 Brian S Walden
2014-01-09 19:51 ` Clem Cole [this message]
-- strict thread matches above, loose matches on Subject: below --
2014-01-16 8:56 Brian S Walden
[not found] <mailman.1.1389661202.22836.tuhs@minnie.tuhs.org>
2014-01-14 22:44 ` Pepe
2014-01-15 1:33 ` Warner Losh
2014-01-15 1:43 ` Larry McVoy
2014-01-15 2:13 ` John Cowan
2014-01-15 4:02 ` Chris Nehren
2014-01-15 4:39 ` Steve Nickolas
2014-01-10 17:08 Brian S Walden
2014-01-10 14:55 Brian S Walden
2014-01-10 17:05 ` Ron Natalie
2014-01-10 1:41 Brian S Walden
2014-01-10 13:17 ` scj
2014-01-10 14:03 ` Ronald Natalie
2014-01-10 0:15 Brian S Walden
2014-01-10 1:01 ` Larry McVoy
2014-01-10 15:16 ` Clem Cole
2014-01-10 15:21 ` Larry McVoy
2014-01-09 21:43 Doug McIlroy
2014-01-09 21:29 Brian S Walden
2014-01-09 22:03 ` Clem Cole
2014-01-10 0:59 ` John Cowan
2014-01-10 4:28 ` Greg 'groggy' Lehey
2014-01-10 10:15 ` Tim Bradshaw
2014-01-09 10:59 Tim Bradshaw
2014-01-09 12:46 ` Ronald Natalie
2014-01-09 14:56 ` Clem Cole
2014-01-09 15:17 ` Tim Bradshaw
2014-01-09 15:31 ` Clem Cole
2014-01-09 18:18 ` Dario Niedermann
2014-01-09 18:31 ` Ron Natalie
2014-01-09 18:48 ` Clem Cole
2014-01-09 19:48 ` Armando Stettner
2014-01-09 19:52 ` Clem Cole
2014-01-09 18:37 ` Tim Bradshaw
2014-01-09 18:55 ` Warner Losh
2014-01-10 16:20 ` Ed Carp
2014-01-09 17:01 ` Jeremy C. Reed
2014-01-09 18:40 ` Clem Cole
2014-01-09 19:13 ` John Cowan
2014-01-09 20:19 ` Tim Newsham
2014-01-09 20:43 ` Warner Losh
2014-01-10 10:09 ` Tim Bradshaw
2014-01-10 17:18 ` John Cowan
2014-01-12 21:19 ` Tim Bradshaw
2014-01-13 7:05 ` John Cowan
2014-01-13 10:37 ` Tim Bradshaw
2014-01-13 16:15 ` John Cowan
2014-01-13 16:53 ` SZIGETI Szabolcs
2014-01-13 18:16 ` John Cowan
2014-01-09 22:57 ` Cyrille Lefevre
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