Commit 72103bd1 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by Rusty Russell

virtio-pci: fix use after free

Commit 31a3ddda introduced
a use after free in virtio-pci. The main issue is
that the release method signals removal of the virtio device,
while remove signals removal of the pci device.

For example, on driver removal or hot-unplug,
virtio_pci_release_dev is called before virtio_pci_remove.
We then might get a crash as virtio_pci_remove tries to use the
device freed by virtio_pci_release_dev.

We allocate/free all resources together with the
pci device, so we can leave the release method empty.
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Acked-by: default avatarAmit Shah <amit.shah@redhat.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
parent 1ea6b8f4
...@@ -594,11 +594,11 @@ static struct virtio_config_ops virtio_pci_config_ops = { ...@@ -594,11 +594,11 @@ static struct virtio_config_ops virtio_pci_config_ops = {
static void virtio_pci_release_dev(struct device *_d) static void virtio_pci_release_dev(struct device *_d)
{ {
struct virtio_device *dev = container_of(_d, struct virtio_device, /*
dev); * No need for a release method as we allocate/free
struct virtio_pci_device *vp_dev = to_vp_device(dev); * all devices together with the pci devices.
* Provide an empty one to avoid getting a warning from core.
kfree(vp_dev); */
} }
/* the PCI probing function */ /* the PCI probing function */
...@@ -686,6 +686,7 @@ static void __devexit virtio_pci_remove(struct pci_dev *pci_dev) ...@@ -686,6 +686,7 @@ static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
pci_iounmap(pci_dev, vp_dev->ioaddr); pci_iounmap(pci_dev, vp_dev->ioaddr);
pci_release_regions(pci_dev); pci_release_regions(pci_dev);
pci_disable_device(pci_dev); pci_disable_device(pci_dev);
kfree(vp_dev);
} }
#ifdef CONFIG_PM #ifdef CONFIG_PM
......
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