From patchwork Mon May 31 20:30:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Berg X-Patchwork-Id: 450703 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 1E364C47098 for ; Mon, 31 May 2021 20:31:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EEC1E61159 for ; Mon, 31 May 2021 20:31:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232345AbhEaUdA (ORCPT ); Mon, 31 May 2021 16:33:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232182AbhEaUcs (ORCPT ); Mon, 31 May 2021 16:32:48 -0400 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CE703C06174A; Mon, 31 May 2021 13:30:30 -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 1lnoYP-000F87-0d; Mon, 31 May 2021 22:30:29 +0200 From: Johannes Berg To: linux-wireless@vger.kernel.org Cc: stable@vger.kernel.org, Mathy Vanhoef Subject: [PATCH v4.9 01/10] mac80211: assure all fragments are encrypted Date: Mon, 31 May 2021 22:30:12 +0200 Message-Id: <20210531203021.180010-2-johannes@sipsolutions.net> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210531203021.180010-1-johannes@sipsolutions.net> References: <20210531203021.180010-1-johannes@sipsolutions.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Mathy Vanhoef commit 965a7d72e798eb7af0aa67210e37cf7ecd1c9cad upstream. Do not mix plaintext and encrypted fragments in protected Wi-Fi networks. This fixes CVE-2020-26147. Previously, an attacker was able to first forward a legitimate encrypted fragment towards a victim, followed by a plaintext fragment. The encrypted and plaintext fragment would then be reassembled. For further details see Section 6.3 and Appendix D in the paper "Fragment and Forge: Breaking Wi-Fi Through Frame Aggregation and Fragmentation". Because of this change there are now two equivalent conditions in the code to determine if a received fragment requires sequential PNs, so we also move this test to a separate function to make the code easier to maintain. Cc: stable@vger.kernel.org Signed-off-by: Mathy Vanhoef Link: https://lore.kernel.org/r/20210511200110.30c4394bb835.I5acfdb552cc1d20c339c262315950b3eac491397@changeid Signed-off-by: Johannes Berg --- net/mac80211/rx.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index c38d68131d02..e5760492c27d 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -1942,6 +1942,16 @@ ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata, return NULL; } +static bool requires_sequential_pn(struct ieee80211_rx_data *rx, __le16 fc) +{ + return rx->key && + (rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP || + rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP_256 || + rx->key->conf.cipher == WLAN_CIPHER_SUITE_GCMP || + rx->key->conf.cipher == WLAN_CIPHER_SUITE_GCMP_256) && + ieee80211_has_protected(fc); +} + static ieee80211_rx_result debug_noinline ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx) { @@ -1987,12 +1997,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx) /* This is the first fragment of a new frame. */ entry = ieee80211_reassemble_add(rx->sdata, frag, seq, rx->seqno_idx, &(rx->skb)); - if (rx->key && - (rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP || - rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP_256 || - rx->key->conf.cipher == WLAN_CIPHER_SUITE_GCMP || - rx->key->conf.cipher == WLAN_CIPHER_SUITE_GCMP_256) && - ieee80211_has_protected(fc)) { + if (requires_sequential_pn(rx, fc)) { int queue = rx->security_idx; /* Store CCMP/GCMP PN so that we can verify that the @@ -2034,11 +2039,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx) u8 pn[IEEE80211_CCMP_PN_LEN], *rpn; int queue; - if (!rx->key || - (rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP && - rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP_256 && - rx->key->conf.cipher != WLAN_CIPHER_SUITE_GCMP && - rx->key->conf.cipher != WLAN_CIPHER_SUITE_GCMP_256)) + if (!requires_sequential_pn(rx, fc)) return RX_DROP_UNUSABLE; memcpy(pn, entry->last_pn, IEEE80211_CCMP_PN_LEN); for (i = IEEE80211_CCMP_PN_LEN - 1; i >= 0; i--) {