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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 E054CC433ED for ; Mon, 12 Apr 2021 09:08:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B583661388 for ; Mon, 12 Apr 2021 09:08:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237933AbhDLJIo (ORCPT ); Mon, 12 Apr 2021 05:08:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:47052 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238987AbhDLIzR (ORCPT ); Mon, 12 Apr 2021 04:55:17 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8804761263; Mon, 12 Apr 2021 08:54:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1618217660; bh=4wbeKZkoyAOU2fztr/DIcBWidLILZA3OAF2I2RO21SY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bTmfxq7gifUutQUa+jY1MoVgwlPKbYhY82mtNBesVTTRl05g5OaNlTTltlnKXEnUy DLJB1t0I+JsHjI0linET62xx1gKQ84KReEOD5yppMAeQOJLlVagjNZSgS8EtjC/Ouu R9sO+MD3TvMrynhijYyFDBdR18k6NZZN3K5pRb4g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Johannes Berg , syzbot+72b99dcf4607e8c770f3@syzkaller.appspotmail.com Subject: [PATCH 5.10 063/188] nl80211: fix beacon head validation Date: Mon, 12 Apr 2021 10:39:37 +0200 Message-Id: <20210412084015.753371404@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210412084013.643370347@linuxfoundation.org> References: <20210412084013.643370347@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johannes Berg commit 9a6847ba1747858ccac53c5aba3e25c54fbdf846 upstream. If the beacon head attribute (NL80211_ATTR_BEACON_HEAD) is too short to even contain the frame control field, we access uninitialized data beyond the buffer. Fix this by checking the minimal required size first. We used to do this until S1G support was added, where the fixed data portion has a different size. Reported-and-tested-by: syzbot+72b99dcf4607e8c770f3@syzkaller.appspotmail.com Suggested-by: Eric Dumazet Fixes: 1d47f1198d58 ("nl80211: correctly validate S1G beacon head") Signed-off-by: Johannes Berg Link: https://lore.kernel.org/r/20210408154518.d9b06d39b4ee.Iff908997b2a4067e8d456b3cb96cab9771d252b8@changeid Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/wireless/nl80211.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -209,9 +209,13 @@ static int validate_beacon_head(const st unsigned int len = nla_len(attr); const struct element *elem; const struct ieee80211_mgmt *mgmt = (void *)data; - bool s1g_bcn = ieee80211_is_s1g_beacon(mgmt->frame_control); unsigned int fixedlen, hdrlen; + bool s1g_bcn; + if (len < offsetofend(typeof(*mgmt), frame_control)) + goto err; + + s1g_bcn = ieee80211_is_s1g_beacon(mgmt->frame_control); if (s1g_bcn) { fixedlen = offsetof(struct ieee80211_ext, u.s1g_beacon.variable);