From: Szymon Heidrich Date: Tue, 3 Jan 2023 09:17:09 +0000 (+0100) Subject: usb: rndis_host: Secure rndis_query check against int overflow X-Git-Tag: v5.15.92~481 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=11cd4ec6359d90b13ffb8f85a9df8637f0cf8d95;p=platform%2Fkernel%2Flinux-rpi.git 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: ddda08624013 ("USB: rndis_host, various cleanups") Signed-off-by: Szymon Heidrich Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- diff --git a/drivers/net/usb/rndis_host.c b/drivers/net/usb/rndis_host.c index bedd36a..e5f6614 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)