6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Foster Snowhill <forst@xxxxxx>
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@xxxxxxxxxxxxxxx
Signed-off-by: Foster Snowhill <forst@xxxxxx>
Reviewed-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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++;
