Jason Wang
2021-May-25 06:23 UTC
[PATCH] virtio_console: Assure used length from device is limited
? 2021/5/25 ??12:53, Xie Yongji ??:> The buf->len might come from an untrusted device. This > ensures the value would not exceed the size of the buffer > to avoid data corruption or loss. > > Signed-off-by: Xie Yongji <xieyongji at bytedance.com>Acked-by: Jason Wang <jasowang at redhat.com>> --- > drivers/char/virtio_console.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > index 1c40ca6d76ba..598863e6daf8 100644 > --- a/drivers/char/virtio_console.c > +++ b/drivers/char/virtio_console.c > @@ -475,7 +475,7 @@ static struct port_buffer *get_inbuf(struct port *port) > > buf = virtqueue_get_buf(port->in_vq, &len); > if (buf) { > - buf->len = len; > + buf->len = min(len, buf->size); > buf->offset = 0; > port->stats.bytes_received += len; > } > @@ -1709,7 +1709,7 @@ static void control_work_handler(struct work_struct *work) > while ((buf = virtqueue_get_buf(vq, &len))) { > spin_unlock(&portdev->c_ivq_lock); > > - buf->len = len; > + buf->len = min(len, buf->size); > buf->offset = 0; > > handle_control_message(vq->vdev, portdev, buf);