Commit 429fa68b authored by Foster Snowhill's avatar Foster Snowhill Committed by Paolo Abeni
Browse files

usbnet: ipheth: check that DPE points past NCM header 



By definition, a DPE points at the start of a network frame/datagram.
Thus it makes no sense for it to point at anything that's part of the
NCM header. It is not a security issue, but merely an indication of
a malformed DPE.

Enforce that all DPEs point at the data portion of the URB, past the
NCM header.

Fixes: a2d274c6 ("usbnet: ipheth: add CDC NCM support")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarFoster Snowhill <forst@pen.gy>
Reviewed-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent c219427e

drivers/net/usb/ipheth.c

+2 −1
Original line number Diff line number Diff line
@@ -242,7 +242,8 @@ static int ipheth_rcvbulk_callback_ncm(struct urb *urb) 
	dpe = ncm0->dpe16;

	while (le16_to_cpu(dpe->wDatagramIndex) != 0 &&

	       le16_to_cpu(dpe->wDatagramLength) != 0) {

		if (le16_to_cpu(dpe->wDatagramIndex) >= urb->actual_length ||

		if (le16_to_cpu(dpe->wDatagramIndex) < IPHETH_NCM_HEADER_SIZE ||

		    le16_to_cpu(dpe->wDatagramIndex) >= urb->actual_length ||

		    le16_to_cpu(dpe->wDatagramLength) > urb->actual_length -

		    le16_to_cpu(dpe->wDatagramIndex)) {

			dev->net->stats.rx_length_errors++;