6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Foster Snowhill forst@pen.gy
commit 429fa68b58cefb9aa9de27e4089637298b46b757 upstream.
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: a2d274c62e44 ("usbnet: ipheth: add CDC NCM support") Cc: stable@vger.kernel.org Signed-off-by: Foster Snowhill forst@pen.gy Reviewed-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/usb/ipheth.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/net/usb/ipheth.c +++ b/drivers/net/usb/ipheth.c @@ -241,7 +241,8 @@ static int ipheth_rcvbulk_callback_ncm(s 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++;