usb: rndis_host: Secure rndis_query check against int overflow

[ Upstream commit c7dd13805f8b8fc1ce3b6d40f6aff47e66b72ad2 ]

Variables off and len typed as uint32 in rndis_query function
are controlled by incoming RNDIS response message thus their
value may be manipulated. Setting off to a unexpectetly large
value will cause the sum with len and 8 to overflow and pass
the implemented validation step. Consequently the response
pointer will be referring to a location past the expected
buffer boundaries allowing information leakage e.g. via
RNDIS_OID_802_3_PERMANENT_ADDRESS OID.

Fixes: ddda086240 ("USB: rndis_host, various cleanups")
Signed-off-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Szymon Heidrich 2023-01-03 10:17:09 +01:00 committed by Greg Kroah-Hartman
parent a07b4895b9
commit ebe6d2fcf7

View File

@ -255,7 +255,8 @@ static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
off = le32_to_cpu(u.get_c->offset);
len = le32_to_cpu(u.get_c->len);
if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
if (unlikely((off > CONTROL_BUFFER_SIZE - 8) ||
(len > CONTROL_BUFFER_SIZE - 8 - off)))
goto response_error;
if (*reply_len != -1 && len != *reply_len)