Re: [PATCH] virtio_pci: fix use after free on release
From: Jerome Marchand <hidden>
Date: 2016-01-14 14:55:39
On 01/14/2016 03:04 PM, Michael S. Tsirkin wrote:
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.
That does make KASan happy.
Fixes: 63bd62a08ca4 ("virtio_pci: defer kfree until release callback")
Reported-by: Jerome Marchand <redacted>
Cc: stable@vger.kernel.org
Cc: Sasha Levin <redacted>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>Tested-by: Jerome Marchand <redacted> Thanks, Jerome
quoted hunk
--- drivers/virtio/virtio_pci_common.c | 2 ++ 1 file changed, 2 insertions(+)diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c index 36205c2..f6bed86 100644 --- a/drivers/virtio/virtio_pci_common.c +++ b/drivers/virtio/virtio_pci_common.c@@ -545,6 +545,7 @@ err_enable_device: 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 = {