From patchwork Wed Jun 17 08:26:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Markus Theil X-Patchwork-Id: 11609407 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3742014DD for ; Wed, 17 Jun 2020 08:27:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B17E20C09 for ; Wed, 17 Jun 2020 08:27:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726625AbgFQI1G (ORCPT ); Wed, 17 Jun 2020 04:27:06 -0400 Received: from smail.rz.tu-ilmenau.de ([141.24.186.67]:49908 "EHLO smail.rz.tu-ilmenau.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725967AbgFQI1F (ORCPT ); Wed, 17 Jun 2020 04:27:05 -0400 Received: from legolas.fritz.box (unknown [87.147.49.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smail.rz.tu-ilmenau.de (Postfix) with ESMTPSA id 449E5580075; Wed, 17 Jun 2020 10:27:03 +0200 (CEST) From: Markus Theil To: johannes@sipsolutions.net Cc: linux-wireless@vger.kernel.org, Markus Theil , kernel test robot Subject: [PATCH v3 2/2] mac80211: allow rx of mesh eapol frames with default rx key Date: Wed, 17 Jun 2020 10:26:37 +0200 Message-Id: <20200617082637.22670-3-markus.theil@tu-ilmenau.de> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200617082637.22670-1-markus.theil@tu-ilmenau.de> References: <20200617082637.22670-1-markus.theil@tu-ilmenau.de> MIME-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Without this patch, eapol frames cannot be received in mesh mode, when 802.1X should be used. Initially only a MGTK is defined, which is found and set as rx->key, when there are no other keys set. ieee80211_drop_unencrypted would then drop these eapol frames, as they are data frames without encryption and there exists some rx->key. Fix this by differentiating between mesh eapol frames and other data frames with existing rx->key. Allow mesh mesh eapol frames only if they are for our vif address. If a check for eapol frames fails, the previous drop check is executed (thanks to a kernel test bot, which found an issue in a previous patch version here). With this patch in-place, ieee80211_rx_h_mesh_fwding continues after the ieee80211_drop_unencrypted check and notices, that these eapol frames have to be delivered locally, as they should. Reported-by: kernel test robot Signed-off-by: Markus Theil --- net/mac80211/rx.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 21854a61a2b7..60293a9fa3dc 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -2396,6 +2396,7 @@ static int ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx) static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc) { + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data; struct sk_buff *skb = rx->skb; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); @@ -2406,12 +2407,37 @@ static int ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx, __le16 fc) if (status->flag & RX_FLAG_DECRYPTED) return 0; + /* check mesh EAPOL frames first */ + if (unlikely(rx->sta && ieee80211_vif_is_mesh(&rx->sdata->vif) && ieee80211_is_data(fc))) { + struct ieee80211s_hdr *mesh_hdr; + u16 hdr_len = ieee80211_hdrlen(fc); + u16 ethertype_offset; + __be16 ethertype; + + /* make sure fixed part of mesh header is there, also checks skb len */ + if (!pskb_may_pull(rx->skb, hdr_len + 6)) + goto drop_check; + + mesh_hdr = (struct ieee80211s_hdr *)(skb->data + hdr_len); + ethertype_offset = hdr_len + ieee80211_get_mesh_hdrlen(mesh_hdr) + + sizeof(rfc1042_header); + if (!pskb_may_pull(rx->skb, ethertype_offset + sizeof(ethertype)) || + !ether_addr_equal(hdr->addr1, rx->sdata->vif.addr)) + goto drop_check; + + skb_copy_bits(rx->skb, ethertype_offset, ðertype, 2); + if (ethertype == rx->sdata->control_port_protocol) + goto pass_frame; + } + +drop_check: /* Drop unencrypted frames if key is set. */ if (unlikely(!ieee80211_has_protected(fc) && !ieee80211_is_any_nullfunc(fc) && ieee80211_is_data(fc) && rx->key)) return -EACCES; +pass_frame: return 0; }