[Spice-devel] [PATCH spice-server v2 1/3] Dispatcher: validate received message types

[Frediano Ziglio]

> 
> Although dispatcher_send_message() does not allow you to send a message
> type that is invalid for a dispatcher, it still makes sense to verify
> that the type is valid in the receiver. This should only be possible in
> the case of some severe problem such as memory corruption, so if it is
> invalid, we simply abort.
> 
> Signed-off-by: Jonathon Jongsma <jjongsma at redhat.com>

Acked-by: Frediano Ziglio <fziglio at redhat.com>

> ---
>  server/dispatcher.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/server/dispatcher.c b/server/dispatcher.c
> index 4e03ea046..6f2c4d85e 100644
> --- a/server/dispatcher.c
> +++ b/server/dispatcher.c
> @@ -285,6 +285,10 @@ static int dispatcher_handle_single_read(Dispatcher
> *dispatcher)
>          /* no messsage */
>          return 0;
>      }
> +    if (type >= dispatcher->priv->max_message_type) {
> +        spice_error("Invalid message type for this dispatcher: %u", type);
> +        return 0;
> +    }
>      msg = &dispatcher->priv->messages[type];
>      if (read_safe(dispatcher->priv->recv_fd, payload, msg->size, 1) == -1) {
>          spice_printerr("error reading from dispatcher: %d", errno);