Commit 956b56a9 authored by Alex Williamson's avatar Alex Williamson

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: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 1a695a90
...@@ -228,9 +228,9 @@ static int vfio_intx_set_signal(struct vfio_pci_device *vdev, int fd) ...@@ -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) 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].unmask);
vfio_virqfd_disable(&vdev->ctx[0].mask); vfio_virqfd_disable(&vdev->ctx[0].mask);
vfio_intx_set_signal(vdev, -1);
vdev->irq_type = VFIO_PCI_NUM_IRQS; vdev->irq_type = VFIO_PCI_NUM_IRQS;
vdev->num_ctx = 0; vdev->num_ctx = 0;
kfree(vdev->ctx); kfree(vdev->ctx);
...@@ -401,13 +401,13 @@ static void vfio_msi_disable(struct vfio_pci_device *vdev, bool msix) ...@@ -401,13 +401,13 @@ static void vfio_msi_disable(struct vfio_pci_device *vdev, bool msix)
struct pci_dev *pdev = vdev->pdev; struct pci_dev *pdev = vdev->pdev;
int i; int i;
vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix);
for (i = 0; i < vdev->num_ctx; i++) { for (i = 0; i < vdev->num_ctx; i++) {
vfio_virqfd_disable(&vdev->ctx[i].unmask); vfio_virqfd_disable(&vdev->ctx[i].unmask);
vfio_virqfd_disable(&vdev->ctx[i].mask); vfio_virqfd_disable(&vdev->ctx[i].mask);
} }
vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix);
if (msix) { if (msix) {
pci_disable_msix(vdev->pdev); pci_disable_msix(vdev->pdev);
kfree(vdev->msix); kfree(vdev->msix);
......
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