@@ -843,6 +843,9 @@ static void wake_futex(struct futex_q *q)
 {
 	struct task_struct *p = q->task;
 
+	if (WARN(q->pi_state || q->rt_waiter, "refusing to wake PI futex\n"))
+		return;
+
 	/*
 	 * We set q->lock_ptr = NULL _before_ we wake up the task. If
 	 * a non-futex wake up happens on another CPU then the task

@@ -1078,6 +1081,10 @@ retry_private:
 
 	plist_for_each_entry_safe(this, next, head, list) {
 		if (match_futex (&this->key, &key1)) {
+			if (this->pi_state || this->rt_waiter) {
+				ret = -EINVAL;
+				goto out_unlock;
+			}
 			wake_futex(this);
 			if (++ret >= nr_wake)
 				break;

@@ -1090,6 +1097,10 @@ retry_private:
 		op_ret = 0;
 		plist_for_each_entry_safe(this, next, head, list) {
 			if (match_futex (&this->key, &key2)) {
+				if (this->pi_state || this->rt_waiter) {
+					ret = -EINVAL;
+					goto out_unlock;
+				}
 				wake_futex(this);
 				if (++op_ret >= nr_wake2)
 					break;

@@ -1098,6 +1109,7 @@ retry_private:
 		ret += op_ret;
 	}
 
+out_unlock:
 	double_unlock_hb(hb1, hb2);
 out_put_keys:
 	put_futex_key(&key2);

@@ -1387,9 +1399,13 @@ retry_private:
 		/*
 		 * FUTEX_WAIT_REQEUE_PI and FUTEX_CMP_REQUEUE_PI should always
 		 * be paired with each other and no other futex ops.
+		 *
+		 * We should never be requeueing a futex_q with a pi_state,
+		 * which is awaiting a futex_unlock_pi().
 		 */
 		if ((requeue_pi && !this->rt_waiter) ||
-		    (!requeue_pi && this->rt_waiter)) {
+		    (!requeue_pi && this->rt_waiter) ||
+		    this->pi_state) {
 			ret = -EINVAL;
 			break;
 		}