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authorAmit Shah <amit.shah@redhat.com>2011-03-14 17:45:02 +0530
committerRusty Russell <rusty@rustcorp.com.au>2011-04-21 22:57:00 +0930
commit31a3ddda166cda86d2b5111e09ba4bda5239fae6 (patch)
tree9cd6af0a5a7b59b4452db2fa84545ce782c4006b /drivers/virtio/virtio_pci.c
parentb3258ff1d6086bd2b9eeb556844a868ad7d49bc8 (diff)
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op-kernel-dev-31a3ddda166cda86d2b5111e09ba4bda5239fae6.tar.gz
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>
Diffstat (limited to 'drivers/virtio/virtio_pci.c')
-rw-r--r--drivers/virtio/virtio_pci.c15
1 files changed, 8 insertions, 7 deletions
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 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_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 @@ static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
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
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