static void vfio_msi_disable(struct vfio_pci_device *vdev, bool msix)
{
	struct pci_dev *pdev = vdev->pdev;
	int i;

	for (i = 0; i < vdev->num_ctx; i++) {
		vfio_virqfd_disable(&vdev->ctx[i].unmask);
		vfio_virqfd_disable(&vdev->ctx[i].mask);
	}

	vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix);

	pci_free_irq_vectors(pdev);

	/*
	 * Both disable paths above use pci_intx_for_msi() to clear DisINTx
	 * via their shutdown paths.  Restore for NoINTx devices.
	 */
	if (vdev->nointx)
		pci_intx(pdev, 0);

	vdev->irq_type = VFIO_PCI_NUM_IRQS;
	vdev->num_ctx = 0;
	kfree(vdev->ctx);
}

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.