Commit 4aeec398 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Alex Williamson
Browse files

vfio/pci: Re-order vfio_pci_probe() 



vfio_add_group_dev() must be called only after all of the private data in
vdev is fully setup and ready, otherwise there could be races with user
space instantiating a device file descriptor and starting to call ops.

For instance vfio_pci_reflck_attach() sets vdev->reflck and
vfio_pci_open(), called by fops open, unconditionally derefs it, which
will crash if things get out of order.

Fixes: cc20d799 ("vfio/pci: Introduce VF token")
Fixes: e309df5b ("vfio/pci: Parallelize device open and release")
Fixes: 6eb70187 ("vfio-pci: Move idle devices to D3hot power state")
Fixes: ecaa1f6a ("vfio-pci: Add VGA arbiter client")
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMax Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Message-Id: <8-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com>
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 61e90817

drivers/vfio/pci/vfio_pci.c

+9 −8
Original line number Diff line number Diff line
@@ -2030,13 +2030,9 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
	INIT_LIST_HEAD(&vdev->vma_list);

	init_rwsem(&vdev->memory_lock);



	ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);

	if (ret)

		goto out_free;



	ret = vfio_pci_reflck_attach(vdev);

	if (ret)

		goto out_del_group_dev;

		goto out_free;

	ret = vfio_pci_vf_init(vdev);

	if (ret)

		goto out_reflck;
@@ -2060,15 +2056,20 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
		vfio_pci_set_power_state(vdev, PCI_D3hot);

	}



	return ret;

	ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);

	if (ret)

		goto out_power;

	return 0;



out_power:

	if (!disable_idle_d3)

		vfio_pci_set_power_state(vdev, PCI_D0);

out_vf:

	vfio_pci_vf_uninit(vdev);

out_reflck:

	vfio_pci_reflck_put(vdev->reflck);

out_del_group_dev:

	vfio_del_group_dev(&pdev->dev);

out_free:

	kfree(vdev->pm_save);

	kfree(vdev);

out_group_put:

	vfio_iommu_group_put(group, &pdev->dev);