From: Xie Yongji <xieyongji@xxxxxxxxxxxxx> [ Upstream commit d00d8da5869a2608e97cfede094dfc5e11462a46 ] 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@xxxxxxxxxxxxx> Acked-by: Jason Wang <jasowang@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210525125622.1203-1-xieyongji@xxxxxxxxxxxxx Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 1836cc56e357..673522874cec 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_t(size_t, len, buf->size); buf->offset = 0; port->stats.bytes_received += len; } @@ -1712,7 +1712,7 @@ 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_t(size_t, len, buf->size); buf->offset = 0; handle_control_message(vq->vdev, portdev, buf); -- 2.30.2
