Re: [PATCH 3/4] security: capabilities patch (version 0.4.4), part 3/4: introduce new capabilities

David Madore
2006-09-10T20:03:49Z

On Sun, Sep 10, 2006 at 01:56:43PM -0400, Joshua Brindle wrote:
> To expand on this a little, some of the capabilities you are looking to
> add are of very little if any use without being able to specify objects.
> For example, CAP_REG_OPEN is whether the process can open any file
> instead of specific ones. How many applications open no files whatsoever
> in practice? Even if there are some as soon as they change and need to
> open a file they'll need this capability and will be able to open any.
> CAP_REG_WRITE has the same problem. For a description of why
> CAP_REG_EXEC is meaningless see the digsig thread on the LSM list from
> earlier this year.

CAP_REG_OPEN and CAP_REG_EXEC might be useful only for demonstration
purposes, but I've *often* wished I could run a program without
CAP_REG_WRITE because I wasn't root and I wanted to make *sure* it
didn't write any file anywhere. Instead I had to run them from a
user-mode-linux, which is horribly messy and doesn't work well (and,
at best, with a noticeable slowdown).

Again, I ask: is SElinux useable if you aren't root? (Assuming it's
activated, of course: I mean, can you create new policies to make
certain programs run with restricted privileges?) I thought it
wasn't, but maybe I'm wrong.

--
David A. Madore
(david.madore@ens.fr,
http://www.madore.org/~david/ )