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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 BB8B2C43331 for ; Tue, 12 Nov 2019 23:51:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9AF762196E for ; Tue, 12 Nov 2019 23:51:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727247AbfKLXuw (ORCPT ); Tue, 12 Nov 2019 18:50:52 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:57450 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727113AbfKLXug (ORCPT ); Tue, 12 Nov 2019 18:50:36 -0500 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iUfvf-0008JG-5d; Tue, 12 Nov 2019 23:50:35 +0000 Received: from ben by deadeye with local (Exim 4.93-RC1) (envelope-from ) id 1iUfvd-00058F-PM; Tue, 12 Nov 2019 23:50:33 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Nicolas Waisman" , "Will Deacon" , "Johannes Berg" , "Kees Cook" Date: Tue, 12 Nov 2019 23:48:21 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 24/25] cfg80211: wext: avoid copying malformed SSIDs In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.77-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon commit 4ac2813cc867ae563a1ba5a9414bfb554e5796fa upstream. Ensure the SSID element is bounds-checked prior to invoking memcpy() with its length field, when copying to userspace. Cc: Kees Cook Reported-by: Nicolas Waisman Signed-off-by: Will Deacon Link: https://lore.kernel.org/r/20191004095132.15777-2-will@kernel.org [adjust commit log a bit] Signed-off-by: Johannes Berg Signed-off-by: Ben Hutchings --- net/wireless/wext-sme.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/net/wireless/wext-sme.c +++ b/net/wireless/wext-sme.c @@ -225,6 +225,7 @@ int cfg80211_mgd_wext_giwessid(struct ne struct iw_point *data, char *ssid) { struct wireless_dev *wdev = dev->ieee80211_ptr; + int ret = 0; /* call only for station! */ if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION)) @@ -242,7 +243,10 @@ int cfg80211_mgd_wext_giwessid(struct ne if (ie) { data->flags = 1; data->length = ie[1]; - memcpy(ssid, ie + 2, data->length); + if (data->length > IW_ESSID_MAX_SIZE) + ret = -EINVAL; + else + memcpy(ssid, ie + 2, data->length); } rcu_read_unlock(); } else if (wdev->wext.connect.ssid && wdev->wext.connect.ssid_len) { @@ -252,7 +256,7 @@ int cfg80211_mgd_wext_giwessid(struct ne } wdev_unlock(wdev); - return 0; + return ret; } int cfg80211_mgd_wext_siwap(struct net_device *dev,