Subject: Re: allowing unpriv users to bind to priv ports
To: Luke Mewburn <lukem@wasabisystems.com>
From: Joe Reed <jnr@po.cwru.edu>
List: tech-kern
Date: 09/25/2002 20:52:04
> *however*, we now have systrace in the tree, and that allows much more
> granular control over what system calls may be called. I have been
> meaning to test the following concept for a while:
> * define IPNOPRIVPORTS in my kernel
> * set a systrace policy to allow certain uids or gids to bind to
> a specific port (e.g, "uid=named to tcp/udp port 53"
> * set a default systrace policy; prevent uid!=0 from binding port <
> 1024
i have thought of this too, however this follows the paradigm of "having an
insecure system, then using rules to lock it down." my patch follows the
paradigm of "have a locked down system, and only open what you want." both
are effective, when done right. but personally, i'd rather start with
default security.
--joe