[refpolicy] [RFC] Security policy reworks for SE-PostgreSQL

[Christopher J. PeBenito]

On Tue, 2009-04-21 at 11:51 +0900, KaiGai Kohei wrote:
> Chris, the attached patch is the part you already OK'ed.
> 
> - rework: Add a comment of "deprecated" for deprecated permissions.
> - bugfix: MCS policy did not constrain the following permissions.
>     db_database:{getattr}
>     db_table:{getattr lock}
>     db_column:{getattr}
>     db_procedure:{drop getattr setattr}
>     db_blob:{getattr import export}
> - rework: db_table:{lock} is moved to reader side, because it makes
>   impossible to refer read-only table with foreign-key constraint.
>   (FK checks internally acquire explicit locks.)
> - bugfix: some of permissions in db_procedure class are allowed
>   on sepgsql_trusted_proc_t, but it is a domain, not a procedure.
>   It should allow them on sepgsql_trusted_proc_exec_t.
>   I also aliased sepgsql_proc_t as sepgsql_proc_exec_t to avoid
>   such kind of confusion, as Chris suggested before.
> - rework: we should not allow db_procedure:{install} on the
>   sepgsql_trusted_proc_exec_t, because of a risk to invoke trusted
>   procedure implicitly.
> - bugfix: MLS policy dealt db_blob:{export} as writer-side permission,
>   but it is required whrn the largeobject is refered.
> - bugfix: MLS policy didn't constrain the db_procedure class.
> 
> I'll send the rest of patches after we determine what prefix is preferable
> for unprivileged domains.

Merged.

> Christopher J. PeBenito wrote:
> > On Mon, 2009-04-06 at 11:15 +0900, KaiGai Kohei wrote:
> >> The attached patch provides some of reworks and bugfuxes
> >> except for new object classes and permissions.
> >>
> >> - rework: Add a comment of "not currently in use" for deprecated
> >>   permissions, but its definitions are not removed.
> > 
> > "deprecated" should be sufficient.
> > 
> >> - bugfix: MCS policy did not constrain the following permissions.
> >>     db_database:{getattr}
> >>     db_table:{getattr lock}
> >>     db_column:{getattr}
> >>     db_procedure:{drop getattr setattr}
> >>     db_blob:{getattr import export}
> > 
> > Looks ok to me.
> > 
> >> - rework: All the newly created database objects by unprivileged
> >>   clients are prefixed with "user_", and these are controled via
> >>   sepgsql_enable_users_ddl.
> > 
> > I don't think we should be mixing user content with other unpriv
> > clients.
> > 
> >>   The current policy allows httpd_t to created a function labeled
> >>   as sepgsql_proc_t which is also allowed to be installed as a
> >>   system internal entity (db_procedure:{install}).
> >>   It is a potentially risk for trojan horse.
> >>
> >> - rework: postgresql_role() shares most part of postgresql_unpriv_client().
> > 
> > See above comment.
> > 
> >> - bugfix: some of permissions in db_procedure class are allowed
> >>   on sepgsql_trusted_proc_t, but it is a domain, not a procedure.
> >>   It should allow them on sepgsql_trusted_proc_exec_t.
> >>   I also aliased sepgsql_proc_t as sepgsql_proc_exec_t to avoid
> >>   such kind of confusion, as Chris suggested before.
> >>
> >> - rework: we should not allow db_procedure:{install} on the
> >>   sepgsql_trusted_proc_exec_t, because of a risk to invoke trusted
> >>   procedure implicitly.
> >>
> >> - rework: db_table:{lock} is moved to reader side, because it makes
> >>   impossible to refer read-only table with foreign-key constraint.
> >>   (FK checks internally acquire explicit locks.)
> >>
> >> - bugfix: MLS policy dealt db_blob:{export} as writer-side permission,
> >>   but it is required whrn the largeobject is refered.
> >>
> >> - bugfix: MLS policy didn't constrain the db_procedure class.
> > 
> > Seems ok.
> > 
> > It would be helpful to break up the patch into a set to make it easier
> > to review in the future.
> > 
> 
> 
-- 
Chris PeBenito
Tresys Technology, LLC
(410) 290-1411 x150