diff options
| author | Alex Williamson <alex.williamson@redhat.com> | 2016-05-30 15:50:10 +0200 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2016-05-30 15:50:10 +0200 |
| commit | 956b56a984ddf10aa69b25318dc04430101beed6 (patch) | |
| tree | 5d698890a0f6ab87af4c647908395f51d30e8356 | |
| parent | Linux 4.7-rc1 (diff) | |
| download | linux-956b56a984ddf10aa69b25318dc04430101beed6.tar.xz linux-956b56a984ddf10aa69b25318dc04430101beed6.zip | |
vfio/pci: Fix ordering of eventfd vs virqfd shutdown
Both the INTx and MSI/X disable paths do an eventfd_ctx_put() for the
trigger eventfd before calling vfio_virqfd_disable() any potential
mask and unmask eventfds. This opens a use-after-free race where an
inopportune irqfd can reference the freed signalling eventfd. Reorder
to avoid this possibility.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| -rw-r--r-- | drivers/vfio/pci/vfio_pci_intrs.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c index e9ea3fef144a..15ecfc9c5f6c 100644 --- a/drivers/vfio/pci/vfio_pci_intrs.c +++ b/drivers/vfio/pci/vfio_pci_intrs.c @@ -228,9 +228,9 @@ static int vfio_intx_set_signal(struct vfio_pci_device *vdev, int fd) static void vfio_intx_disable(struct vfio_pci_device *vdev) { - vfio_intx_set_signal(vdev, -1); vfio_virqfd_disable(&vdev->ctx[0].unmask); vfio_virqfd_disable(&vdev->ctx[0].mask); + vfio_intx_set_signal(vdev, -1); vdev->irq_type = VFIO_PCI_NUM_IRQS; vdev->num_ctx = 0; kfree(vdev->ctx); @@ -401,13 +401,13 @@ static void vfio_msi_disable(struct vfio_pci_device *vdev, bool msix) struct pci_dev *pdev = vdev->pdev; int i; - vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix); - 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); + if (msix) { pci_disable_msix(vdev->pdev); kfree(vdev->msix); |