On Sat, Feb 16, 2019 at 01:04:12PM +0100, Dominick Grift wrote: > 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` > The `install_policy.sh` script should probably also do a bash file test for `checkpolicy` and fail gracefully if its not found -- Key fingerprint = 5F4D 3CDB D3F8 3652 FBD8 02D5 3B6C 5F1D 2C7B 6B02 https://sks-keyservers.net/pks/lookup?op=get&search=0x3B6C5F1D2C7B6B02 Dominick Grift
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