From: Foster Snowhill <forst@xxxxxx>
commit c219427ed296f94bb4b91d08626776dc7719ee27 upstream.
Originally, it was possible for the DPE length check to overflow if
wDatagramIndex + wDatagramLength > U16_MAX. This could lead to an OoB
read.
Move the wDatagramIndex term to the other side of the inequality.
An existing condition ensures that wDatagramIndex < urb->actual_length.
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 | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/usb/ipheth.c b/drivers/net/usb/ipheth.c
index 46afb95ffabe..45daae234cb8 100644
--- a/drivers/net/usb/ipheth.c
+++ b/drivers/net/usb/ipheth.c
@@ -243,8 +243,8 @@ static int ipheth_rcvbulk_callback_ncm(struct urb *urb)
while (le16_to_cpu(dpe->wDatagramIndex) != 0 &&
le16_to_cpu(dpe->wDatagramLength) != 0) {
if (le16_to_cpu(dpe->wDatagramIndex) >= urb->actual_length ||
- le16_to_cpu(dpe->wDatagramIndex) +
- le16_to_cpu(dpe->wDatagramLength) > urb->actual_length) {
+ le16_to_cpu(dpe->wDatagramLength) > urb->actual_length -
+ le16_to_cpu(dpe->wDatagramIndex)) {
dev->net->stats.rx_length_errors++;
return retval;
}
--
2.48.1
Patches currently in stable-queue which might be from forst@xxxxxx are
queue-6.6/usbnet-ipheth-use-static-ndp16-location-in-urb.patch
queue-6.6/usbnet-ipheth-check-that-dpe-points-past-ncm-header.patch
queue-6.6/usbnet-ipheth-fix-dpe-oob-read.patch
queue-6.6/usbnet-ipheth-document-scope-of-ncm-implementation.patch
queue-6.6/usbnet-ipheth-fix-possible-overflow-in-dpe-length-check.patch
queue-6.6/usbnet-ipheth-refactor-ncm-datagram-loop.patch
queue-6.6/usbnet-ipheth-break-up-ncm-header-size-computation.patch
