Re: [Qemu-devel] [PATCH RESEND 1/3] usb-ccid: make ccid_write_data_block() cope with null buffers

[Marc-André Lureau]

Hi

On Thu, Mar 23, 2017 at 11:44 AM Gerd Hoffmann <address@hidden> wrote:

>   Hi,
>
> > > +    if (len == 0) {
> > > +        return;
> >
> > Correct only if messages without data always have the same meaning as no
> > message.  Gerd?
>
> Not a ccid expert, but looking through the code it seems writing a
> (reply) data block with status and without payload (data = NULL and len
> = 0) is perfectly fine and can happen in case no (virtual) smartcard is
> inserted into the card reader.  Which this patch breaks.  So,
>
> NACK.
>

 oops, there are hard-coded calls with NULL/0. I suppose to fix clang
warning, it would need to check if data != null for memcpy.
-- 
Marc-André Lureau