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

	if (test_bit(NIC_STATE_TESTING, &priv->state))
		return -EBUSY;

	priv->link = 0;
	netif_carrier_off(ndev);

	ret = netif_set_real_num_tx_queues(ndev, h->q_num);
	if (ret < 0) {
		netdev_err(ndev, "netif_set_real_num_tx_queues fail, ret=%d!\n",
			   ret);
		return ret;
	}

	ret = netif_set_real_num_rx_queues(ndev, h->q_num);
	if (ret < 0) {
		netdev_err(ndev,
			   "netif_set_real_num_rx_queues fail, ret=%d!\n", ret);
		return ret;
	}

	ret = hns_nic_net_up(ndev);
	if (ret) {
		netdev_err(ndev,
			   "hns net up fail, ret=%d!\n", ret);
		return ret;
	}

	return 0;
}

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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.