| From 1b69caa8e84259b82dd15658fae6dd739a6bd3fc Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 25 May 2021 20:56:22 +0800 |
| Subject: virtio_console: Assure used length from device is limited |
| |
| From: Xie Yongji <xieyongji@bytedance.com> |
| |
| [ 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> |
| --- |
| 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 |
| |
