From: sven.vermeulen@siphos.be (Sven Vermeulen)
Date: Mon, 17 Dec 2012 11:26:04 +0100
Subject: [refpolicy] [PATCH 5/8] Dontaudit getsched on all domains
In-Reply-To: <1355739655.2269.7.camel@localhost>
References: <1355737370-27628-1-git-send-email-sven.vermeulen@siphos.be>
	<1355737370-27628-6-git-send-email-sven.vermeulen@siphos.be>
	<1355739655.2269.7.camel@localhost>
Message-ID: <20121217102603.GA1030@siphos.be>
To: refpolicy@oss.tresys.com
List-Id: refpolicy.oss.tresys.com

On Mon, Dec 17, 2012 at 11:20:55AM +0100, grift wrote:
> > The htop utility will attempt to get the scheduling information of all
> > processes. This information however does not seem to be needed for its
> > information (no difference in output when allowed or not).
[...]
> > +interface(`domain_dontaudit_getsched_all_domains',`
> > +	gen_require(`
> > +		attribute domain;
> > +	')
> > +
> > +	dontaudit $1 domain:process getsched;
> > +')
[...]
> > --- a/policy/modules/system/userdomain.if
> > +++ b/policy/modules/system/userdomain.if
> > @@ -523,6 +523,8 @@ template(`userdom_common_user_template',`
> >  	dev_read_sound_mixer($1_t)
> >  	dev_write_sound_mixer($1_t)
> >  
> > +	domain_dontaudit_getsched_all_domains($1_t)
> 
> That is too coarse in my view.
> 
> This will also dontaudit legitimate access for processes needing this
> running in the user domain.
> 
> Lets say i have this app that depends on this permission for itself:
> 
> allow staff_t self:process { signal getsched };
> 
> Then this rule will silently hide that access

I understand that, but the other method would be to create
*_dontaudit_getsched for each and every possible module, and add it in the
user domain definition fully loaded with optional_policy() statements.

And if the user domain doesn't need getsched itself, then running htop will
generate denials anyhow for self (i.e. in your above example, you'll get
denials for staff_t getsched on itself) so eventually you'll add in a
staff_dontaudit_getsched() for that too?

Another alternative could be to run htop in its own domain, but that doesn't
make sense imo...

Wkr,
	Sven Vermeulen