static int vfio_intx_set_signal(struct vfio_pci_device *vdev, int fd)
{
	struct pci_dev *pdev = vdev->pdev;
	unsigned long irqflags = IRQF_SHARED;
	struct eventfd_ctx *trigger;
	unsigned long flags;
	int ret;

	if (vdev->ctx[0].trigger) {
		free_irq(pdev->irq, vdev);
		kfree(vdev->ctx[0].name);
		eventfd_ctx_put(vdev->ctx[0].trigger);
		vdev->ctx[0].trigger = NULL;
	}

	if (fd < 0) /* Disable only */
		return 0;

	vdev->ctx[0].name = kasprintf(GFP_KERNEL, "vfio-intx(%s)",
				      pci_name(pdev));
	if (!vdev->ctx[0].name)
		return -ENOMEM;

	trigger = eventfd_ctx_fdget(fd);
	if (IS_ERR(trigger)) {
		kfree(vdev->ctx[0].name);
		return PTR_ERR(trigger);
	}

	vdev->ctx[0].trigger = trigger;

	if (!vdev->pci_2_3)
		irqflags = 0;

	ret = request_irq(pdev->irq, vfio_intx_handler,
			  irqflags, vdev->ctx[0].name, vdev);
	if (ret) {
		vdev->ctx[0].trigger = NULL;
		kfree(vdev->ctx[0].name);
		eventfd_ctx_put(trigger);
		return ret;
	}

	/*
	 * INTx disable will stick across the new irq setup,
	 * disable_irq won't.
	 */
	spin_lock_irqsave(&vdev->irqlock, flags);
	if (!vdev->pci_2_3 && vdev->ctx[0].masked)
		disable_irq_nosync(pdev->irq);
	spin_unlock_irqrestore(&vdev->irqlock, flags);

	return 0;
}

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.