From: Philippe Mathieu-Daudé Date: Mon, 4 Jun 2018 15:14:19 +0000 (-0300) Subject: usb: correctly handle Zero Length Packets X-Git-Tag: qemu-xen-4.11.1^2~2 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=17e3fcbc51eddf06f50d59fb96a21a3298b25cd3;p=qemu-xen.git usb: correctly handle Zero Length Packets USB Specification Revision 2.0, §5.5.3: The Data stage of a control transfer from an endpoint to the host is complete when the endpoint does one of the following: • Has transferred exactly the amount of data specified during the Setup stage • Transfers a packet with a payload size less than wMaxPacketSize or transfers a zero-length packet" hw/usb/redirect.c:802:9: warning: Declared variable-length array (VLA) has zero size uint8_t buf[size]; ^~~~~~~~~~~ ~~~~ Reported-by: Clang Static Analyzer Signed-off-by: Philippe Mathieu-Daudé Message-id: 20180604151421.23385-2-f4bug@amsat.org Signed-off-by: Gerd Hoffmann (cherry picked from commit bf78fb1c1b61a819a47f7a1dbecf9934b9f32a0d) Signed-off-by: Michael Roth --- diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c index ec174309db..f4cb05bacf 100644 --- a/hw/usb/redirect.c +++ b/hw/usb/redirect.c @@ -795,7 +795,7 @@ static void usbredir_handle_bulk_data(USBRedirDevice *dev, USBPacket *p, usbredirparser_peer_has_cap(dev->parser, usb_redir_cap_32bits_bulk_length)); - if (ep & USB_DIR_IN) { + if (ep & USB_DIR_IN || size == 0) { usbredirparser_send_bulk_packet(dev->parser, p->id, &bulk_packet, NULL, 0); } else {