From: Xie Yongji <xieyongji@bytedance.com> stable inclusion from linux-4.19.198 commit b5fba782ccd3d12a14f884cd20f255fc9c0eec0c -------------------------------- [ 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@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210525125622.1203-1-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.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 b353a5e5f8b1c..46188d0a54b8a 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -488,7 +488,7 @@ 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; } @@ -1738,7 +1738,7 @@ 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); -- 2.25.1