From: Szymon Heidrich szymon.heidrich@gmail.com
[ 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: ddda08624013 ("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 --- drivers/net/usb/rndis_host.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/usb/rndis_host.c b/drivers/net/usb/rndis_host.c index bedd36ab5cf0..e5f6614da5ac 100644 --- a/drivers/net/usb/rndis_host.c +++ b/drivers/net/usb/rndis_host.c @@ -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)