int snd_seq_create_kernel_client(struct snd_card *card, int client_index,
				 const char *name_fmt, ...)
{
	struct snd_seq_client *client;
	va_list args;

	if (snd_BUG_ON(in_interrupt()))
		return -EBUSY;

	if (card && client_index >= SNDRV_SEQ_CLIENTS_PER_CARD)
		return -EINVAL;
	if (card == NULL && client_index >= SNDRV_SEQ_GLOBAL_CLIENTS)
		return -EINVAL;

	if (mutex_lock_interruptible(&register_mutex))
		return -ERESTARTSYS;

	if (card) {
		client_index += SNDRV_SEQ_GLOBAL_CLIENTS
			+ card->number * SNDRV_SEQ_CLIENTS_PER_CARD;
		if (client_index >= SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN)
			client_index = -1;
	}

	/* empty write queue as default */
	client = seq_create_client1(client_index, 0);
	if (client == NULL) {
		mutex_unlock(&register_mutex);
		return -EBUSY;	/* failure code */
	}
	usage_alloc(&client_usage, 1);

	client->accept_input = 1;
	client->accept_output = 1;
	client->data.kernel.card = card;
		
	va_start(args, name_fmt);
	vsnprintf(client->name, sizeof(client->name), name_fmt, args);
	va_end(args);

	client->type = KERNEL_CLIENT;
	mutex_unlock(&register_mutex);

	/* make others aware this new client */
	snd_seq_system_client_ev_client_start(client->number);
	
	/* return client number to caller */
	return client->number;
}

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.