virtio_pci: Prevent double-free of pci regions after device hot-unplug
In the case where a virtio-console port is in use (opened by a program)
and a virtio-console device is removed, the port is kept around but all
the virtio-related state is assumed to be gone.
When the port is finally released (close() called), we call
device_destroy() on the port's device. This results in the parent
device's structures to be freed as well. This includes the PCI regions
for the virtio-console PCI device.
Once this is done, however, virtio_pci_release_dev() kicks in, as the
last ref to the virtio device is now gone, and attempts to do
pci_iounmap(pci_dev, vp_dev->ioaddr);
pci_release_regions(pci_dev);
pci_disable_device(pci_dev);
which results in a double-free warning.
Move the code that releases regions, etc., to the virtio_pci_remove()
function, and all that's now left in release_dev is the final freeing of
the vp_dev.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 4fb5b2b..4bcc8b8 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -590,15 +590,10 @@
static void virtio_pci_release_dev(struct device *_d)
{
- struct virtio_device *dev = container_of(_d, struct virtio_device, dev);
+ struct virtio_device *dev = container_of(_d, struct virtio_device,
+ dev);
struct virtio_pci_device *vp_dev = to_vp_device(dev);
- struct pci_dev *pci_dev = vp_dev->pci_dev;
- vp_del_vqs(dev);
- pci_set_drvdata(pci_dev, NULL);
- pci_iounmap(pci_dev, vp_dev->ioaddr);
- pci_release_regions(pci_dev);
- pci_disable_device(pci_dev);
kfree(vp_dev);
}
@@ -681,6 +676,12 @@
struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
unregister_virtio_device(&vp_dev->vdev);
+
+ vp_del_vqs(&vp_dev->vdev);
+ pci_set_drvdata(pci_dev, NULL);
+ pci_iounmap(pci_dev, vp_dev->ioaddr);
+ pci_release_regions(pci_dev);
+ pci_disable_device(pci_dev);
}
#ifdef CONFIG_PM