selinux: fix misuse of mutex_is_locked()

commit ce2fc71 upstream.

mutex_is_locked() tests whether the mutex is locked *by any task*, while
here we want to test if it is held *by the current task*. To avoid
false/missed WARNINGs, use lockdep_assert_is_held() and
lockdep_assert_is_not_held() instead, which do the right thing (though
they are a no-op if CONFIG_LOCKDEP=n).

Cc: stable@vger.kernel.org
Fixes: 2554a48 ("selinux: measure state and policy capabilities")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

security/selinux/ima.c

@@ -77,7 +77,7 @@ void selinux_ima_measure_state_locked(struct selinux_state *state)
 	size_t policy_len;
 	int rc = 0;
 
-	WARN_ON(!mutex_is_locked(&state->policy_mutex));
+	lockdep_assert_held(&state->policy_mutex);
 
 	state_str = selinux_ima_collect_state(state);
 	if (!state_str) {
@@ -117,7 +117,7 @@ void selinux_ima_measure_state_locked(struct selinux_state *state)
  */
 void selinux_ima_measure_state(struct selinux_state *state)
 {
-	WARN_ON(mutex_is_locked(&state->policy_mutex));
+	lockdep_assert_not_held(&state->policy_mutex);
 
 	mutex_lock(&state->policy_mutex);
 	selinux_ima_measure_state_locked(state);