static int hns_nic_net_up(struct net_device *ndev)
{
	struct hns_nic_priv *priv = netdev_priv(ndev);
	struct hnae_handle *h = priv->ae_handle;
	int i, j;
	int ret;

	ret = hns_nic_init_irq(priv);
	if (ret != 0) {
		netdev_err(ndev, "hns init irq failed! ret=%d\n", ret);
		return ret;
	}

	for (i = 0; i < h->q_num * 2; i++) {
		ret = hns_nic_ring_open(ndev, i);
		if (ret)
			goto out_has_some_queues;
	}

	ret = h->dev->ops->set_mac_addr(h, ndev->dev_addr);
	if (ret)
		goto out_set_mac_addr_err;

	ret = h->dev->ops->start ? h->dev->ops->start(h) : 0;
	if (ret)
		goto out_start_err;

	if (ndev->phydev)
		phy_start(ndev->phydev);

	clear_bit(NIC_STATE_DOWN, &priv->state);
	(void)mod_timer(&priv->service_timer, jiffies + SERVICE_TIMER_HZ);

	return 0;

out_start_err:
	netif_stop_queue(ndev);
out_set_mac_addr_err:
out_has_some_queues:
	for (j = i - 1; j >= 0; j--)
		hns_nic_ring_close(ndev, j);

	set_bit(NIC_STATE_DOWN, &priv->state);

	return ret;
}

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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.