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 X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 08D70C5ACAE for ; Wed, 11 Sep 2019 13:06:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D271D206A1 for ; Wed, 11 Sep 2019 13:06:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727919AbfIKNGK (ORCPT ); Wed, 11 Sep 2019 09:06:10 -0400 Received: from s3.sipsolutions.net ([144.76.43.62]:39898 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727837AbfIKNGJ (ORCPT ); Wed, 11 Sep 2019 09:06:09 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1i82Jw-0007pA-9M; Wed, 11 Sep 2019 15:06:04 +0200 Message-ID: Subject: Re: [PATCH] mac80211: Do not send Layer 2 Update frame before authorization From: Johannes Berg To: Jouni Malinen Cc: linux-wireless@vger.kernel.org, David Miller , netdev@vger.kernel.org Date: Wed, 11 Sep 2019 15:06:03 +0200 In-Reply-To: <20190911130305.23704-1-jouni@codeaurora.org> References: <20190911130305.23704-1-jouni@codeaurora.org> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5 (3.30.5-1.fc29) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 2019-09-11 at 16:03 +0300, Jouni Malinen wrote: > The Layer 2 Update frame is used to update bridges when a station roams > to another AP even if that STA does not transmit any frames after the > reassociation. This behavior was described in IEEE Std 802.11F-2003 as > something that would happen based on MLME-ASSOCIATE.indication, i.e., > before completing 4-way handshake. However, this IEEE trial-use > recommended practice document was published before RSN (IEEE Std > 802.11i-2004) and as such, did not consider RSN use cases. Furthermore, > IEEE Std 802.11F-2003 was withdrawn in 2006 and as such, has not been > maintained amd should not be used anymore. > > Sending out the Layer 2 Update frame immediately after association is > fine for open networks (and also when using SAE, FT protocol, or FILS > authentication when the station is actually authenticated by the time > association completes). However, it is not appropriate for cases where > RSN is used with PSK or EAP authentication since the station is actually > fully authenticated only once the 4-way handshake completes after > authentication and attackers might be able to use the unauthenticated > triggering of Layer 2 Update frame transmission to disrupt bridge > behavior. > > Fix this by postponing transmission of the Layer 2 Update frame from > station entry addition to the point when the station entry is marked > authorized. Similarly, send out the VLAN binding update only if the STA > entry has already been authorized. Reviewed-by: Johannes Berg Dave, if you were still planning to send a pull request to Linus before he closes the tree on Sunday this would be good to include (and we should also backport it to stable later). If not, I can pick it up afterwards, let me know. Thanks, johannes