Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 16 Sep 2012 13:02:21 -0700
From:      Michael Sierchio <kudzu@tenebras.com>
To:        Matthias Apitz <guru@unixarea.de>
Cc:        Matthew Seaman <matthew@freebsd.org>, freebsd-questions@freebsd.org
Subject:   Re: What are negative permissions?
Message-ID:  <CAHu1Y72kt22JmWR1CpaQT%2B4=oQXgdEVkFxjWYge%2B7E_tDHGC7Q@mail.gmail.com>
In-Reply-To: <20120916195013.GA1358@tiny.Sisis.de>
References:  <50562121.2030507@dreamchaser.org> <50562A8C.9040504@FreeBSD.org> <20120916195013.GA1358@tiny.Sisis.de>

next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, Sep 16, 2012 at 12:50 PM, Matthias Apitz <guru@unixarea.de> wrote:

> El d=EDa Sunday, September 16, 2012 a las 08:37:48PM +0100, Matthew Seama=
n
> escribi=F3:
>
> > It's where the group ownership of a file gives it fewer permissions tha=
n
> > are allowed for the world in general.
> >
> > Suppose you have a file with these permissions and ownership:
> >
> > foo bar -rwx---r-x
> >
> > ...
>
> So far so good (and correct) the theory. But, could you imagine a real
> world example where this makes any sense?
>

Group permissions are rather blunt, and if you want fine-grained access
controls, you'll need to enable ACLs.  However...

Imagine, if you will, a group entitled "guest," with the semantics you
might normally associate with that name - then using negative group
permissions on a directory effectively prevents traversal beyond that point
for members of that group.

- M



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAHu1Y72kt22JmWR1CpaQT%2B4=oQXgdEVkFxjWYge%2B7E_tDHGC7Q>