Re: suenv

[Paul Goyette <paul%whooppee.com@localhost>]

On Tue, 23 Oct 2012, Emmanuel Dreyfus wrote:

> snip>
> In that situation, and perhaps in others, it would be nice if the
> administrator could configure a trusted environement for setUID
> binaries. We would need a way to feed a colon-separated list of
> environement variables (example:
> LD_PRELOAD=/usr/lib/libpthread.so:FOO=bar). I see two way of dealing
> with it:
> 1) lookup in /etc/suenv.d/$progname (probably libc based)
> 2) use sysctl security.suenv.$progname (kernel based)
>
> I like the second one, which is simple to implement and cannot be messed
> up with incorrect file permissions. I would fix my problem like this:
> sysctl -w security.suenv.su=LD_PRELOAD=/usr/lib/libpthread.so
> sysctl -w security.suenv.login=LD_PRELOAD=/usr/lib/libpthread.so
>
> Opinions?

This would require that the entire set of programs be known in advance, 
in order to create the sysctl(9) nodes.  As far as I can tell, usermode 
code has no mechanism to create new nodes for other suid binaries that 
you might want to add.



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