 static void queue_delete(struct snd_seq_queue *q)
 {
 	/* stop and release the timer */
	mutex_lock(&q->timer_mutex);
 	snd_seq_timer_stop(q->timer);
 	snd_seq_timer_close(q);
	mutex_unlock(&q->timer_mutex);
 	/* wait until access free */
 	snd_use_lock_sync(&q->use_lock);
 	/* release resources... */
	snd_seq_prioq_delete(&q->tickq);
	snd_seq_prioq_delete(&q->timeq);
	snd_seq_timer_delete(&q->timer);

	kfree(q);
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.