static void vfio_pci_disable(struct vfio_pci_device *vdev)
{
	struct pci_dev *pdev = vdev->pdev;
	struct vfio_pci_dummy_resource *dummy_res, *tmp;
	int i, bar;

	/* Stop the device from further DMA */
	pci_clear_master(pdev);

	vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE |
				VFIO_IRQ_SET_ACTION_TRIGGER,
				vdev->irq_type, 0, 0, NULL);

	vdev->virq_disabled = false;

	for (i = 0; i < vdev->num_regions; i++)
		vdev->region[i].ops->release(vdev, &vdev->region[i]);

	vdev->num_regions = 0;
	kfree(vdev->region);
	vdev->region = NULL; /* don't krealloc a freed pointer */

	vfio_config_free(vdev);

	for (bar = PCI_STD_RESOURCES; bar <= PCI_STD_RESOURCE_END; bar++) {
		if (!vdev->barmap[bar])
			continue;
		pci_iounmap(pdev, vdev->barmap[bar]);
		pci_release_selected_regions(pdev, 1 << bar);
		vdev->barmap[bar] = NULL;
	}

	list_for_each_entry_safe(dummy_res, tmp,
				 &vdev->dummy_resources_list, res_next) {
		list_del(&dummy_res->res_next);
		release_resource(&dummy_res->resource);
		kfree(dummy_res);
	}

	vdev->needs_reset = true;

	/*
	 * If we have saved state, restore it.  If we can reset the device,
	 * even better.  Resetting with current state seems better than
	 * nothing, but saving and restoring current state without reset
	 * is just busy work.
	 */
	if (pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state)) {
		pr_info("%s: Couldn't reload %s saved state\n",
			__func__, dev_name(&pdev->dev));

		if (!vdev->reset_works)
			goto out;

		pci_save_state(pdev);
	}

	/*
	 * Disable INTx and MSI, presumably to avoid spurious interrupts
	 * during reset.  Stolen from pci_reset_function()
	 */
	pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);

	/*
	 * Try to reset the device.  The success of this is dependent on
	 * being able to lock the device, which is not always possible.
	 */
	if (vdev->reset_works && !pci_try_reset_function(pdev))
		vdev->needs_reset = false;

	pci_restore_state(pdev);
out:
	pci_disable_device(pdev);

	vfio_pci_try_bus_reset(vdev);

	if (!disable_idle_d3)
		pci_set_power_state(pdev, PCI_D3hot);
}

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.