vhost: ensure vhost_ops are set before calling iotlb callback

This patch fixes a crash that happens when vhost-user iommu
support is enabled and vhost-user socket is closed.

When it happens, if an IOTLB invalidation notification is sent
by the IOMMU, vhost_ops's NULL pointer is dereferenced.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Maxime Coquelin 2017-06-30 18:04:21 +02:00 committed by Michael S. Tsirkin
parent 552a1e01a4
commit 384b557da1

View File

@ -309,7 +309,10 @@ int vhost_backend_update_device_iotlb(struct vhost_dev *dev,
return -EINVAL;
}
return dev->vhost_ops->vhost_send_device_iotlb_msg(dev, &imsg);
if (dev->vhost_ops && dev->vhost_ops->vhost_send_device_iotlb_msg)
return dev->vhost_ops->vhost_send_device_iotlb_msg(dev, &imsg);
return -ENODEV;
}
int vhost_backend_invalidate_device_iotlb(struct vhost_dev *dev,
@ -321,7 +324,10 @@ int vhost_backend_invalidate_device_iotlb(struct vhost_dev *dev,
imsg.size = len;
imsg.type = VHOST_IOTLB_INVALIDATE;
return dev->vhost_ops->vhost_send_device_iotlb_msg(dev, &imsg);
if (dev->vhost_ops && dev->vhost_ops->vhost_send_device_iotlb_msg)
return dev->vhost_ops->vhost_send_device_iotlb_msg(dev, &imsg);
return -ENODEV;
}
int vhost_backend_handle_iotlb_msg(struct vhost_dev *dev,