From nobody Fri Dec 19 20:51:21 2025 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 0EFDFC4321E for ; Thu, 13 Oct 2022 18:06:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231440AbiJMSGG (ORCPT ); Thu, 13 Oct 2022 14:06:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231239AbiJMSDv (ORCPT ); Thu, 13 Oct 2022 14:03:51 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E294B15B334; Thu, 13 Oct 2022 11:03:36 -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 dfw.source.kernel.org (Postfix) with ESMTPS id C0AE66194D; Thu, 13 Oct 2022 18:00:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8211BC433B5; Thu, 13 Oct 2022 18:00:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1665684032; bh=IxQ0xOPd/CgxYSCw3RHLoSKvbRbv71Q5pnfxySmwIXg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HDi832MrhVajrwc/qZQstyp4UhkTSjpSDJg3gIvzuRECDxhKeZEJEKf6QHR32lYxw UzUp4XZJaC63j7ugcf0AS7StpnCfWiWoG9wa9vQAbNc1OqCOHA9/s1vnL5EiS99QkU 2UUkbNA1JJE9CNTvrYYmufHbwoJdtA0swRYFCYtg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kees Cook , Johannes Berg Subject: [PATCH 5.19 21/33] wifi: cfg80211/mac80211: reject bad MBSSID elements Date: Thu, 13 Oct 2022 19:52:53 +0200 Message-Id: <20221013175145.987965400@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221013175145.236739253@linuxfoundation.org> References: <20221013175145.236739253@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Johannes Berg commit 8f033d2becc24aa6bfd2a5c104407963560caabc upstream. Per spec, the maximum value for the MaxBSSID ('n') indicator is 8, and the minimum is 1 since a multiple BSSID set with just one BSSID doesn't make sense (the # of BSSIDs is limited by 2^n). Limit this in the parsing in both cfg80211 and mac80211, rejecting any elements with an invalid value. This fixes potentially bad shifts in the processing of these inside the cfg80211_gen_new_bssid() function later. I found this during the investigation of CVE-2022-41674 fixed by the previous patch. Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in sc= anning") Fixes: 78ac51f81532 ("mac80211: support multi-bssid") Reviewed-by: Kees Cook Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/mac80211/util.c | 2 ++ net/wireless/scan.c | 2 ++ 2 files changed, 4 insertions(+) --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -1439,6 +1439,8 @@ static size_t ieee802_11_find_bssid_prof for_each_element_id(elem, WLAN_EID_MULTIPLE_BSSID, start, len) { if (elem->datalen < 2) continue; + if (elem->data[0] < 1 || elem->data[0] > 8) + continue; =20 for_each_element(sub, elem->data + 1, elem->datalen - 1) { u8 new_bssid[ETH_ALEN]; --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -2143,6 +2143,8 @@ static void cfg80211_parse_mbssid_data(s for_each_element_id(elem, WLAN_EID_MULTIPLE_BSSID, ie, ielen) { if (elem->datalen < 4) continue; + if (elem->data[0] < 1 || (int)elem->data[0] > 8) + continue; for_each_element(sub, elem->data + 1, elem->datalen - 1) { u8 profile_len;