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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D27FC4332F for ; Sun, 16 Oct 2022 06:46:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229948AbiJPGqa (ORCPT ); Sun, 16 Oct 2022 02:46:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229849AbiJPGqU (ORCPT ); Sun, 16 Oct 2022 02:46:20 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47CAF3B71B; Sat, 15 Oct 2022 23:46:00 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 0E43AB80B65; Sun, 16 Oct 2022 06:45:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6585CC4314A; Sun, 16 Oct 2022 06:45:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1665902756; bh=M6vEigbkIMDybP7BCXxNZ0YbyifLUWjivpBzJbcRlhQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V1H07BliPDOux2/fxBQr+qy/cmkDBuFdRNE3UnJpCZbgnTIueY0b67vrKw3lLUo8f u10oQk92fvdlJlcTLvpIfqgAWyU78cHkiGBntopDPfEBjEIwec8qbz4BbkizefNEGh 1aNpLfcVVlxmIdlyub4t0LrZBG6fzU6IUKBIih1E= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ilan Peer , Kees Cook , Johannes Berg Subject: [PATCH 5.4 4/4] wifi: mac80211: fix MBSSID parsing use-after-free Date: Sun, 16 Oct 2022 08:46:26 +0200 Message-Id: <20221016064454.478100196@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221016064454.327821011@linuxfoundation.org> References: <20221016064454.327821011@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Johannes Berg Commit ff05d4b45dd89b922578dac497dcabf57cf771c6 upstream. This is a different version of the commit, changed to store the non-transmitted profile in the elems, and freeing it in the few places where it's relevant, since that is only the case when the last argument for parsing (the non-tx BSSID) is non-NULL. When we parse a multi-BSSID element, we might point some element pointers into the allocated nontransmitted_profile. However, we free this before returning, causing UAF when the relevant pointers in the parsed elements are accessed. Fix this by not allocating the scratch buffer separately but as part of the returned structure instead, that way, there are no lifetime issues with it. The scratch buffer introduction as part of the returned data here is taken from MLO feature work done by Ilan. This fixes CVE-2022-42719. Fixes: 5023b14cf4df ("mac80211: support profile split between elements") Co-developed-by: Ilan Peer Signed-off-by: Ilan Peer Reviewed-by: Kees Cook Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/mac80211/ieee80211_i.h | 2 ++ net/mac80211/mlme.c | 6 +++++- net/mac80211/scan.c | 2 ++ net/mac80211/util.c | 7 ++++++- 4 files changed, 15 insertions(+), 2 deletions(-) --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1519,6 +1519,8 @@ struct ieee802_11_elems { u8 country_elem_len; u8 bssid_index_len; + void *nontx_profile; + /* whether a parse error occurred while retrieving these elements */ bool parse_error; }; --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -3299,6 +3299,7 @@ static bool ieee80211_assoc_success(stru sdata_info(sdata, "AP bug: VHT operation missing from AssocResp\n"); } + kfree(bss_elems.nontx_profile); } /* @@ -3883,6 +3884,7 @@ static void ieee80211_rx_mgmt_beacon(str ifmgd->assoc_data->timeout = jiffies; ifmgd->assoc_data->timeout_started = true; run_again(sdata, ifmgd->assoc_data->timeout); + kfree(elems.nontx_profile); return; } @@ -4050,7 +4052,7 @@ static void ieee80211_rx_mgmt_beacon(str ieee80211_report_disconnect(sdata, deauth_buf, sizeof(deauth_buf), true, WLAN_REASON_DEAUTH_LEAVING); - return; + goto free; } if (sta && elems.opmode_notif) @@ -4065,6 +4067,8 @@ static void ieee80211_rx_mgmt_beacon(str elems.cisco_dtpc_elem); ieee80211_bss_info_change_notify(sdata, changed); +free: + kfree(elems.nontx_profile); } void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -216,6 +216,8 @@ ieee80211_bss_info_update(struct ieee802 rx_status, beacon); } + kfree(elems.nontx_profile); + return bss; } --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -1363,6 +1363,11 @@ u32 ieee802_11_parse_elems_crc(const u8 cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE, nontransmitted_profile, nontransmitted_profile_len); + if (!nontransmitted_profile_len) { + nontransmitted_profile_len = 0; + kfree(nontransmitted_profile); + nontransmitted_profile = NULL; + } } crc = _ieee802_11_parse_elems_crc(start, len, action, elems, filter, @@ -1392,7 +1397,7 @@ u32 ieee802_11_parse_elems_crc(const u8 offsetofend(struct ieee80211_bssid_index, dtim_count)) elems->dtim_count = elems->bssid_index->dtim_count; - kfree(nontransmitted_profile); + elems->nontx_profile = nontransmitted_profile; return crc; }