From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754159AbdBEUL1 (ORCPT + 2 others); Sun, 5 Feb 2017 15:11:27 -0500 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:27796 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753438AbdBETYP (ORCPT ); Sun, 5 Feb 2017 14:24:15 -0500 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: Johannes Berg , Willy Tarreau Subject: [PATCH 3.10 267/319] mac80211: discard multicast and 4-addr A-MSDUs Date: Sun, 5 Feb 2017 20:21:29 +0100 Message-Id: <1486322541-8206-168-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1486322541-8206-1-git-send-email-w@1wt.eu> References: <1486322541-8206-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Johannes Berg commit ea720935cf6686f72def9d322298bf7e9bd53377 upstream. In mac80211, multicast A-MSDUs are accepted in many cases that they shouldn't be accepted in: * drop A-MSDUs with a multicast A1 (RA), as required by the spec in 9.11 (802.11-2012 version) * drop A-MSDUs with a 4-addr header, since the fourth address can't actually be useful for them; unless 4-address frame format is actually requested, even though the fourth address is still not useful in this case, but ignored Accepting the first case, in particular, is very problematic since it allows anyone else with possession of a GTK to send unicast frames encapsulated in a multicast A-MSDU, even when the AP has client isolation enabled. Signed-off-by: Johannes Berg Signed-off-by: Willy Tarreau --- net/mac80211/rx.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index cd60be8..f8c7f46 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -1952,16 +1952,22 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx) if (!(status->rx_flags & IEEE80211_RX_AMSDU)) return RX_CONTINUE; - if (ieee80211_has_a4(hdr->frame_control) && - rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN && - !rx->sdata->u.vlan.sta) - return RX_DROP_UNUSABLE; + if (unlikely(ieee80211_has_a4(hdr->frame_control))) { + switch (rx->sdata->vif.type) { + case NL80211_IFTYPE_AP_VLAN: + if (!rx->sdata->u.vlan.sta) + return RX_DROP_UNUSABLE; + break; + case NL80211_IFTYPE_STATION: + if (!rx->sdata->u.mgd.use_4addr) + return RX_DROP_UNUSABLE; + break; + default: + return RX_DROP_UNUSABLE; + } + } - if (is_multicast_ether_addr(hdr->addr1) && - ((rx->sdata->vif.type == NL80211_IFTYPE_AP_VLAN && - rx->sdata->u.vlan.sta) || - (rx->sdata->vif.type == NL80211_IFTYPE_STATION && - rx->sdata->u.mgd.use_4addr))) + if (is_multicast_ether_addr(hdr->addr1)) return RX_DROP_UNUSABLE; skb->dev = dev; -- 2.8.0.rc2.1.gbe9624a