[PATCH 3.10 099/104] virtio-scsi: Fix hotcpu_notifier use-after-free with virtscsi_freeze

Greg Kroah-Hartman
2014-02-04T22:36:42Z

From: Asias He <asias.hejun@gmail.com>

commit f466f75385369a181409e46da272db3de6f5c5cb upstream.

vqs are freed in virtscsi_freeze but the hotcpu_notifier is not
unregistered. We will have a use-after-free usage when the notifier
callback is called after virtscsi_freeze.

Fixes: 285e71ea6f3583a85e27cb2b9a7d8c35d4c0d558
("virtio-scsi: reset virtqueue affinity when doing cpu hotplug")

Signed-off-by: Asias He <asias.hejun@gmail.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/scsi/virtio_scsi.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)

--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -957,6 +957,10 @@ static void virtscsi_remove(struct virti
#ifdef CONFIG_PM
static int virtscsi_freeze(struct virtio_device *vdev)
{
+ struct Scsi_Host *sh = virtio_scsi_host(vdev);
+ struct virtio_scsi *vscsi = shost_priv(sh);
+
+ unregister_hotcpu_notifier(&vscsi->nb);
virtscsi_remove_vqs(vdev);
return 0;
}
@@ -965,8 +969,17 @@ static int virtscsi_restore(struct virti
{
struct Scsi_Host *sh = virtio_scsi_host(vdev);
struct virtio_scsi *vscsi = shost_priv(sh);
+ int err;
+
+ err = virtscsi_init(vdev, vscsi);
+ if (err)
+ return err;
+
+ err = register_hotcpu_notifier(&vscsi->nb);
+ if (err)
+ vdev->config->del_vqs(vdev);

- return virtscsi_init(vdev, vscsi);
+ return err;
}
#endif