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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 B0131C282C4 for ; Mon, 4 Feb 2019 10:58:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8032E2082E for ; Mon, 4 Feb 2019 10:58:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549277925; bh=oblqpb/0dJyJTWnSd+WXajv0UbPjOz3hl0jEs/SHTzE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NT2eRPbUR13q00dEbeYjyA/9/qIA8hf0RX9QHbnTSPVKFtC90YachJ7Hydyx9Fy0o fRdl08+vsSjIq0EVFcQSp4YF5HFuU6o99xg0vecL5cdbX/gWlFInXAjJmBUz0BlEW/ NwnpsYLOluP7D6eguJI6Xc4OhuLOTCVfIn7Esu+c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731865AbfBDK6n (ORCPT ); Mon, 4 Feb 2019 05:58:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:48446 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732238AbfBDKui (ORCPT ); Mon, 4 Feb 2019 05:50:38 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B5AA9217FA; Mon, 4 Feb 2019 10:50:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549277438; bh=oblqpb/0dJyJTWnSd+WXajv0UbPjOz3hl0jEs/SHTzE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mCf2y3NMEFQmxfDYB4s5ooE/PDWHhIPpq7LOCdBPTxmS3UtbNsU7YkvuiopXtDvII OCp8WC+fHsK2ha1L2x3XjnF8A+H6HYGP2FE2DZGjIH3zIzbFuoO2YXz6tVsoBfD/hN qOP4bMDEFhah296Yd2v/Q+c318DuipLaUN2YO/ws= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Guillaume Nault , Jacob Wen , "David S. Miller" Subject: [PATCH 4.20 04/80] l2tp: copy 4 more bytes to linear part if necessary Date: Mon, 4 Feb 2019 11:36:24 +0100 Message-Id: <20190204103620.744852717@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190204103620.287366543@linuxfoundation.org> References: <20190204103620.287366543@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jacob Wen [ Upstream commit 91c524708de6207f59dd3512518d8a1c7b434ee3 ] The size of L2TPv2 header with all optional fields is 14 bytes. l2tp_udp_recv_core only moves 10 bytes to the linear part of a skb. This may lead to l2tp_recv_common read data outside of a skb. This patch make sure that there is at least 14 bytes in the linear part of a skb to meet the maximum need of l2tp_udp_recv_core and l2tp_recv_common. The minimum size of both PPP HDLC-like frame and Ethernet frame is larger than 14 bytes, so we are safe to do so. Also remove L2TP_HDR_SIZE_NOSEQ, it is unused now. Fixes: fd558d186df2 ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts") Suggested-by: Guillaume Nault Signed-off-by: Jacob Wen Acked-by: Guillaume Nault Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/l2tp/l2tp_core.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -83,8 +83,7 @@ #define L2TP_SLFLAG_S 0x40000000 #define L2TP_SL_SEQ_MASK 0x00ffffff -#define L2TP_HDR_SIZE_SEQ 10 -#define L2TP_HDR_SIZE_NOSEQ 6 +#define L2TP_HDR_SIZE_MAX 14 /* Default trace flags */ #define L2TP_DEFAULT_DEBUG_FLAGS 0 @@ -808,7 +807,7 @@ static int l2tp_udp_recv_core(struct l2t __skb_pull(skb, sizeof(struct udphdr)); /* Short packet? */ - if (!pskb_may_pull(skb, L2TP_HDR_SIZE_SEQ)) { + if (!pskb_may_pull(skb, L2TP_HDR_SIZE_MAX)) { l2tp_info(tunnel, L2TP_MSG_DATA, "%s: recv short packet (len=%d)\n", tunnel->name, skb->len);