apparmor: fix profile lookup for unconfined

BugLink: http://bugs.launchpad.net/bugs/978038

also affects apparmor portion of
BugLink: http://bugs.launchpad.net/bugs/987371

The unconfined profile is not stored in the regular profile list, but
change_profile and exec transitions may want access to it when setting
up specialized transitions like switch to the unconfined profile of a
new policy namespace.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

security/apparmor/policy.c

@@ -903,6 +903,10 @@ struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *hname)
 	profile = aa_get_profile(__lookup_profile(&ns->base, hname));
 	read_unlock(&ns->lock);
 
+	/* the unconfined profile is not in the regular profile list */
+	if (!profile && strcmp(hname, "unconfined") == 0)
+		profile = aa_get_profile(ns->unconfined);
+
 	/* refcount released by caller */
 	return profile;
 }