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authorMichael S. Tsirkin <mst@redhat.com>2011-11-07 18:37:05 +0200
committerRusty Russell <rusty@rustcorp.com.au>2011-11-14 11:16:26 +1030
commit72103bd1285211440621f2c46f4fce377584de54 (patch)
tree5bde795c7150c0802fb5a9c9e8603580e6febeae
parent1ea6b8f48918282bdca0b32a34095504ee65bab5 (diff)
downloadlinux-linaro-stable-72103bd1285211440621f2c46f4fce377584de54.tar.gz
virtio-pci: fix use after free
Commit 31a3ddda166cda86d2b5111e09ba4bda5239fae6 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: Michael S. Tsirkin <mst@redhat.com> Acked-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
-rw-r--r--drivers/virtio/virtio_pci.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 79a31e5b4b68..3d1bf41e8892 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -594,11 +594,11 @@ static struct virtio_config_ops virtio_pci_config_ops = {
static void virtio_pci_release_dev(struct device *_d)
{
- struct virtio_device *dev = container_of(_d, struct virtio_device,
- dev);
- struct virtio_pci_device *vp_dev = to_vp_device(dev);
-
- kfree(vp_dev);
+ /*
+ * No need for a release method as we allocate/free
+ * all devices together with the pci devices.
+ * Provide an empty one to avoid getting a warning from core.
+ */
}
/* the PCI probing function */
@@ -686,6 +686,7 @@ static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
pci_iounmap(pci_dev, vp_dev->ioaddr);
pci_release_regions(pci_dev);
pci_disable_device(pci_dev);
+ kfree(vp_dev);
}
#ifdef CONFIG_PM