The attached patch allows unprivileged clients to export from or import
to the largeobject owned by themselves.
The current security policy does not allow them to import/export any
largeobjects without any clear reason.
NOTE: Export of the largeobject means that it dumps whole of the
largeobject into a local file, so SE-PostgreSQL checks both of
db_blob:{read export} on the largeobject and file:{write} on the
local file. Import is a reversal behavior.
KaiGai Kohei
The attached patch fixes incorrect behavior in sepgsql_enable_users_ddl.
The current policy allows users/unprivs to run ALTER TABLE statement
unconditionally, because db_table/db_column:{setattr} is allowed outside
of the boolean. It should be moved to conditional section.
In addition, they are also allowed to db_procedure:{create drop setattr}
for xxxx_sepgsql_proc_exec_t, but it means we allows them to create, drop
or alter definition of the functions unconditionally. So, it also should
be moved to conditional section.
The postgresql.te allows sepgsql_client_type to modify sepgsql_table_t
and sepgsql_sysobj_t when sepgsql_enable_users_ddl is enabled, but
it should not be allowed.
KaiGai Kohei
OK, the attached patch adds the following types for unprivileged clients.
- unpriv_sepgsql_table_t
- unpriv_sepgsql_sysobj_t
- unpriv_sepgsql_proc_exec_t
- unpriv_sepgsql_blob_t
These types are the default for unprivileged and unprefixed domains,
such as httpd_t and others.
In addition, TYPE_TRANSITION rules are moved to outside of tunable
of the sepgsql_enable_users_ddl. IIRC, it was enclosed within the
tunable because UBAC domains (user_t and so on) were allowed to
create sepgsql_table_t, and its default was pointed to this type
when sepgsql_enable_users_ddl is disabled.
However, it has different meanings now, so the TYPE_TRANSITION rules
should be unconditional.
KaiGai Kohei
- 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.
