Re: [PATCH] xhci: check return value from usb_packet_map

[Gerd Hoffmann]

On Tue, Sep 01, 2020 at 10:19:26AM +0530, P J P wrote:
> +-- On Sun, 30 Aug 2020, Alexander Bulekov wrote --+
> | I think there is already a fix queued for this one:
> | https://www.mail-archive.com/qemu-devel@nongnu.org/msg734424.html
> 
>   Yes, it looks similar.
> 
> | > @@ -1615,7 +1615,14 @@ static int xhci_setup_packet(XHCITransfer *xfer)
> | >      xhci_xfer_create_sgl(xfer, dir == USB_TOKEN_IN); /* Also sets 
> int_req */
> | >      usb_packet_setup(&xfer->packet, dir, ep, xfer->streamid,
> | >                       xfer->trbs[0].addr, false, xfer->int_req);
> | > -    usb_packet_map(&xfer->packet, &xfer->sgl);
> | > +    if (usb_packet_map(&xfer->packet, &xfer->sgl) < 0) {
> | > +        DPRINTF("xhci: setup packet failed: pid: 0x%x addr %d ep %d\n",
> | > +                xfer->packet.pid, ep->dev->addr, ep->nr);
> | > +        usb_packet_cleanup(&xfer->packet);
> | > +        qemu_sglist_destroy(&xfer->sgl);
> | > +        return -1;
> 
> We don't need 'usb_packet_cleanup' call? (to confirm)

Oh, didn't notice the difference.  I think we need it, otherwise we leak
iov entries in case the packet has multiple segments and only the second
(or any later) fails to map.

take care,
  Gerd