Messages in this thread Patch in this message | | | From | Xie Yongji <> | Subject | [PATCH] virtio_console: Assure used length from device is limited | Date | Tue, 25 May 2021 12:53:04 +0800 |
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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> --- 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); -- 2.11.0
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