On Fri, Feb 15, 2019 at 02:48:45PM -0500, Stephen Smalley wrote:
<snip>

> 
> Oh, I see: scripts/selinux/install_policy.sh just invokes checkpolicy
> without specifying -U / --handle-unknown, so the policy defaults to deny,
> and that would indeed render dbus-daemon and systemd broken with that
> policy.  Might be as simple to fix as passing -U allow.

I have looked a litte into this and here are some observations:

1. You can boot mdp as-is in permissive mode if you use `checkpolicy` with `-U allow`

2. You need *at least* an `/etc/selinux/dummy/seusers` with `__default__:user_u` and an accompanying `/etc/selinux/dummy/contexts/failsafe_context` with `base_r:base_t` to boot mdp in enforcing

3. There is an issue with checkpolicy and object_r:

PAM libselinux clients such as `login` try to associate `object_r` with the tty and fail.

if you try to append: `role object_r; role object_r types base_t;` to policy.conf and compile that with `checkpolicy` then the `roletype-rule` does *not* end up in the compiled policy for some reason.

thus, you cannot log in because object_r:base_t is not valid.

To hack around this add `default_role * source` rules to policy.conf and recompile.

This will allow you to log into the system locally in enforcing mode.

4. I also noticed that fedoras' ssh seems to hardcode `sshd_net_t` for its "privsep" functionality so, while untested, you probably need an `openssh_contexts` with `privsep_preauth=base_t`

> 
> > 
> > > 
> > > > 
> > > > > 
> > > > > Besides, haven't you always wanted to get a patch accepted into the
> > > > > kernel Dominick? ;)
> > > > 
> > > > Not particularly, no.
> > > > 
> > > 
> > 
> 

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Dominick Grift