From patchwork Thu Apr 8 12:28:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Berg X-Patchwork-Id: 418632 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=-16.7 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=ham 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 C6880C433B4 for ; Thu, 8 Apr 2021 12:28:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9926961041 for ; Thu, 8 Apr 2021 12:28:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231370AbhDHM2o (ORCPT ); Thu, 8 Apr 2021 08:28:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53428 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231314AbhDHM2n (ORCPT ); Thu, 8 Apr 2021 08:28:43 -0400 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43F4FC061760 for ; Thu, 8 Apr 2021 05:28:32 -0700 (PDT) Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94) (envelope-from ) id 1lUTlu-008ztO-An; Thu, 08 Apr 2021 14:28:30 +0200 From: Johannes Berg To: linux-wireless@vger.kernel.org Cc: Johannes Berg Subject: [PATCH] cfg80211: check S1G beacon compat element length Date: Thu, 8 Apr 2021 14:28:27 +0200 Message-Id: <20210408142826.f6f4525012de.I9fdeff0afdc683a6024e5ea49d2daa3cd2459d11@changeid> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Johannes Berg We need to check the length of this element so that we don't access data beyond its end. Fix that. Fixes: 9eaffe5078ca ("cfg80211: convert S1G beacon to scan results") Signed-off-by: Johannes Berg --- net/wireless/scan.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 019952d4fc7d..758eb7d2a706 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -2352,14 +2352,16 @@ cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy, return NULL; if (ext) { - struct ieee80211_s1g_bcn_compat_ie *compat; - u8 *ie; + const struct ieee80211_s1g_bcn_compat_ie *compat; + const struct element *elem; - ie = (void *)cfg80211_find_ie(WLAN_EID_S1G_BCN_COMPAT, - variable, ielen); - if (!ie) + elem = cfg80211_find_elem(WLAN_EID_S1G_BCN_COMPAT, + variable, ielen); + if (!elem) + return NULL; + if (elem->datalen < sizeof(*compat)) return NULL; - compat = (void *)(ie + 2); + compat = (void *)elem->data; bssid = ext->u.s1g_beacon.sa; capability = le16_to_cpu(compat->compat_info); beacon_int = le16_to_cpu(compat->beacon_int);