virtio_pci: fix use after free on release

KASan detected a use-after-free error in virtio-pci remove code. In virtio_pci_remove(), vp_dev is still used after being freed in unregister_virtio_device() (in virtio_pci_release_dev() more precisely). To fix, keep a reference until cleanup is done. Fixes: 63bd62a ("virtio_pci: defer kfree until release callback") Reported-by: Jerome Marchand <[email protected]> Cc: [email protected] Cc: Sasha Levin <[email protected]> Signed-off-by: Michael S. Tsirkin <[email protected]> Tested-by: Jerome Marchand <[email protected]>
KangDroid · Jan 26, 2016 · 2989be0 · 2989be0
1 parent 92e963f
commit 2989be0
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
@@ -545,6 +545,7 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
 static void virtio_pci_remove(struct pci_dev *pci_dev)
 {
 	struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+	struct device *dev = get_device(&vp_dev->vdev.dev);
 
 	unregister_virtio_device(&vp_dev->vdev);
 
@@ -554,6 +555,7 @@ static void virtio_pci_remove(struct pci_dev *pci_dev)
 		virtio_pci_modern_remove(vp_dev);
 
 	pci_disable_device(pci_dev);
+	put_device(dev);
 }
 
 static struct pci_driver virtio_pci_driver = {