From patchwork Mon May 31 20:31:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Berg X-Patchwork-Id: 450696 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 77E5EC47082 for ; Mon, 31 May 2021 20:32:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5E7496052B for ; Mon, 31 May 2021 20:32:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232144AbhEaUdj (ORCPT ); Mon, 31 May 2021 16:33:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232351AbhEaUdV (ORCPT ); Mon, 31 May 2021 16:33:21 -0400 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4D42C061760; Mon, 31 May 2021 13:31:40 -0700 (PDT) Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94.2) (envelope-from ) id 1lnoZX-000FBv-2C; Mon, 31 May 2021 22:31:39 +0200 From: Johannes Berg To: linux-wireless@vger.kernel.org Cc: stable@vger.kernel.org, Mathy Vanhoef Subject: [PATCH v4.14 03/10] mac80211: properly handle A-MSDUs that start with an RFC 1042 header Date: Mon, 31 May 2021 22:31:28 +0200 Message-Id: <20210531203135.180427-4-johannes@sipsolutions.net> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210531203135.180427-1-johannes@sipsolutions.net> References: <20210531203135.180427-1-johannes@sipsolutions.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Mathy Vanhoef commit a1d5ff5651ea592c67054233b14b30bf4452999c upstream. Properly parse A-MSDUs whose first 6 bytes happen to equal a rfc1042 header. This can occur in practice when the destination MAC address equals AA:AA:03:00:00:00. More importantly, this simplifies the next patch to mitigate A-MSDU injection attacks. Cc: stable@vger.kernel.org Signed-off-by: Mathy Vanhoef Link: https://lore.kernel.org/r/20210511200110.0b2b886492f0.I23dd5d685fe16d3b0ec8106e8f01b59f499dffed@changeid Signed-off-by: Johannes Berg --- include/net/cfg80211.h | 5 +++-- net/mac80211/rx.c | 3 ++- net/wireless/util.c | 5 +++-- 3 files changed, 8 insertions(+), 5 deletions(-) diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 030eea38f258..be161f82abc6 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -4338,7 +4338,8 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr); * Return: 0 on success. Non-zero on error. */ int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr, - const u8 *addr, enum nl80211_iftype iftype); + const u8 *addr, enum nl80211_iftype iftype, + bool is_amsdu); /** * ieee80211_data_to_8023 - convert an 802.11 data frame to 802.3 @@ -4350,7 +4351,7 @@ int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr, static inline int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr, enum nl80211_iftype iftype) { - return ieee80211_data_to_8023_exthdr(skb, NULL, addr, iftype); + return ieee80211_data_to_8023_exthdr(skb, NULL, addr, iftype, false); } /** diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 8c126854aa06..be7e37edad12 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -2451,7 +2451,8 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx) if (ieee80211_data_to_8023_exthdr(skb, ðhdr, rx->sdata->vif.addr, - rx->sdata->vif.type)) + rx->sdata->vif.type, + true)) return RX_DROP_UNUSABLE; ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr, diff --git a/net/wireless/util.c b/net/wireless/util.c index 935929b45411..2aef1c487be6 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -422,7 +422,8 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr) EXPORT_SYMBOL(ieee80211_get_mesh_hdrlen); int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr, - const u8 *addr, enum nl80211_iftype iftype) + const u8 *addr, enum nl80211_iftype iftype, + bool is_amsdu) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; struct { @@ -510,7 +511,7 @@ int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr, skb_copy_bits(skb, hdrlen, &payload, sizeof(payload)); tmp.h_proto = payload.proto; - if (likely((ether_addr_equal(payload.hdr, rfc1042_header) && + if (likely((!is_amsdu && ether_addr_equal(payload.hdr, rfc1042_header) && tmp.h_proto != htons(ETH_P_AARP) && tmp.h_proto != htons(ETH_P_IPX)) || ether_addr_equal(payload.hdr, bridge_tunnel_header)))