[refpolicy] [PATCH]: dontaudit sys_module wpa_supplicant

[guido@trentalancia.com (Guido Trentalancia)]

On Sun, 2011-03-20 at 16:56 +0100, Sven Vermeulen wrote:
> On Sun, Mar 20, 2011 at 04:47:27PM +0100, Guido Trentalancia wrote:
> > > The moment you set kernel_load_module(NetworkManager_t) you're all set. The
> > > neverallow is on all domains that do not have the can_load_kernmodule
> > > attribute set, and with kernel_load_moduel() you set it for the specified
> > > domain.
> > 
> > The "neverallow" rule in kernel/kernel.te prevents NetworkManager_t from
> > having the "sys_module" capability.
> 
> In kernel/kernel.te:
> 
>   neverallow ~{ can_load_kernmodule kern_unconfined } self:capability sys_module;
> 
> The kernel_load_module interface:
> 
>   interface(`kernel_load_module',`
>           gen_require(`
>                   attribute can_load_kernmodule;
>           ')
>   
>           allow $1 self:capability sys_module;
>           typeattribute $1 can_load_kernmodule;
>   
>           # load_module() calls stop_machine() which
>           # calls sched_setscheduler()
>           allow $1 self:capability sys_nice;
>           kernel_setsched($1)
>   ')
>   
> When you use kernel_load_module(NetworkManager_t), then the typeattribute
> will add "can_load_kernmodule" as an attribute to the NetworkManager_t
> domain. The neverallow works on all but those domains having
> can_load_kernmodule and/or kern_unconfined set as an attribute.

It seems quite difficult to explain this...

I do not want to break things for distributions that do not want
wpa_supplicant to load kernel modules and in any case I would like to
hear from Christopher.

So unless Dan Walsh changes his mind there needs to be at least one
ifdef (for DISTRO=redhat).

I am happy to prepare a patch which does can_load_kernmodule()/dontaudit
depending on the distribution, but I need to hear from people with
authority for each distribution. And Christopher should decide what
would be the default behaviour.

It is perfectly fine to me (and I would probably be happier) if the
default behaviour is can_load_kernmodule() as I do not particularly like
"dontaudit" for stuff which just logs once (but Christopher has a
different opinion on this, so once again nothing can be changed before
Monday).

Regards,

Guido