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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 833A0C169C4 for ; Thu, 31 Jan 2019 17:20:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E9A32086C for ; Thu, 31 Jan 2019 17:20:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726164AbfAaRUh (ORCPT ); Thu, 31 Jan 2019 12:20:37 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:33274 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725298AbfAaRUh (ORCPT ); Thu, 31 Jan 2019 12:20:37 -0500 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::bf5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 8BEB014F75C9D; Thu, 31 Jan 2019 09:20:36 -0800 (PST) Date: Thu, 31 Jan 2019 09:20:34 -0800 (PST) Message-Id: <20190131.092034.604580592356896496.davem@davemloft.net> To: jian.w.wen@oracle.com Cc: netdev@vger.kernel.org, gnault@redhat.com Subject: Re: [PATCH net] l2tp: copy 4 more bytes to linear part if necessary From: David Miller In-Reply-To: <20190131071856.22120-1-jian.w.wen@oracle.com> References: <20190131071856.22120-1-jian.w.wen@oracle.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 31 Jan 2019 09:20:36 -0800 (PST) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Jacob Wen Date: Thu, 31 Jan 2019 15:18:56 +0800 > 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 Applied and queued up for -stable, thanks.