From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59560C4167B for ; Tue, 29 Nov 2022 22:49:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236752AbiK2WtQ (ORCPT ); Tue, 29 Nov 2022 17:49:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236589AbiK2WtP (ORCPT ); Tue, 29 Nov 2022 17:49:15 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B7091F9DA for ; Tue, 29 Nov 2022 14:48:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1669762105; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HGikrnX364rCVWywnwVxKwVfVWGtIZ6vltliqWh6T0Y=; b=QkbtcaUs6jofWqyQNxcPhO8cZdTiY4ArBcOcNAxY26K8HCUwrR8vNg4FD+tUxj+aRFAxw8 Xe66iKljN4Ehpmm9PcW8kRIuu0fvub0ZjgfXk1RAKhsd+AmSeURnpdlrMBN7msB9WEGmfu Ip2fTNLVXqsAed8aPO71iJGxhEoHvK0= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-624-jPivghd9PsO6geSKUF7Vmw-1; Tue, 29 Nov 2022 17:48:19 -0500 X-MC-Unique: jPivghd9PsO6geSKUF7Vmw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CBC1A84ACA0; Tue, 29 Nov 2022 22:48:12 +0000 (UTC) Received: from localhost.localdomain (unknown [10.22.50.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id BC26F140EBF5; Tue, 29 Nov 2022 22:48:09 +0000 (UTC) Message-ID: <8b11568a8022cdb759a43f34fdcddf33d9abc37c.camel@redhat.com> Subject: Re: [PATCH] USB: disable all RNDIS protocol drivers From: Dan Williams To: Nicolas Cavallari , Greg Kroah-Hartman , linux-kernel@vger.kernel.org Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Kalle Valo , Oleksij Rempel , Maciej =?UTF-8?Q?=C5=BBenczykowski?= , Neil Armstrong , Mauro Carvalho Chehab , Andrzej Pietrasiewicz , Jacopo Mondi , =?UTF-8?Q?=C5=81ukasz?= Stelmach , Laurent Pinchart , linux-usb@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, Ilja Van Sprundel , Joseph Tartaro Date: Tue, 29 Nov 2022 16:48:07 -0600 In-Reply-To: <04ea37cc-d97a-3e00-8a99-135ab38860f2@green-communications.fr> References: <04ea37cc-d97a-3e00-8a99-135ab38860f2@green-communications.fr> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.4 (3.42.4-2.fc35) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 2022-11-23 at 16:40 +0100, Nicolas Cavallari wrote: > On 23/11/2022 13:46, Greg Kroah-Hartman wrote: > > The Microsoft RNDIS protocol is, as designed, insecure and > > vulnerable on > > any system that uses it with untrusted hosts or devices.  Because > > the > > protocol is impossible to make secure, just disable all rndis > > drivers to > > prevent anyone from using them again. > > > > Windows only needed this for XP and newer systems, Windows systems > > older > > than that can use the normal USB class protocols instead, which do > > not > > have these problems. > > > > Android has had this disabled for many years so there should not be > > any > > real systems that still need this. > > I kind of disagree here. I have seen plenty of android devices that > only > support rndis for connection sharing, including my android 11 phone > released in Q3 2020. I suspect the qualcomm's BSP still enable it by > default. > > There are also probably cellular dongles that uses rndis by default. > Maybe ask the ModemManager people ? Yes, there are. Another class of WWAN dongles presented as USB RNDIS to the host, had an onboard DHCP server, and "bridged" that (for lack of a better term) to the WWAN. And like a home router exposed HTTP based management on 192.168.1.1 to control the WWAN stuff. https://openwrt.org/docs/guide-user/network/wan/wwan/ethernetoverusb_rndis RE Wifi, (echoing Johannes) there was one Broadcom chipset, but a bunch of devices used it. I have some though I don't actively use them. But they still work... Dan > > I'm also curious if reimplementing it in userspace would solve the > security problem. >