From: Jason Gunthorpe jgg@nvidia.com
[ Upstream commit 4aeec3984ddc853f7c65903bde472ffdef738bae ]
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: cc20d7999000 ("vfio/pci: Introduce VF token") Fixes: e309df5b0c9e ("vfio/pci: Parallelize device open and release") Fixes: 6eb7018705de ("vfio-pci: Move idle devices to D3hot power state") Fixes: ecaa1f6a0154 ("vfio-pci: Add VGA arbiter client") Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Max Gurtovoy mgurtovoy@nvidia.com Reviewed-by: Kevin Tian kevin.tian@intel.com Reviewed-by: Cornelia Huck cohuck@redhat.com Reviewed-by: Eric Auger eric.auger@redhat.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Message-Id: 8-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com Signed-off-by: Alex Williamson alex.williamson@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/vfio/pci/vfio_pci.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index b73144a6804a..cb7f2dc09e9d 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -2032,13 +2032,9 @@ 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; @@ -2062,15 +2058,20 @@ 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);