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=-10.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY,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 D0404C282C3 for ; Wed, 23 Jan 2019 02:34:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A66221726 for ; Wed, 23 Jan 2019 02:34:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="vSxLMy0y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726953AbfAWCew (ORCPT ); Tue, 22 Jan 2019 21:34:52 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:54976 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726933AbfAWCew (ORCPT ); Tue, 22 Jan 2019 21:34:52 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id x0N2Tsiv116353; Wed, 23 Jan 2019 02:31:22 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id; s=corp-2018-07-02; bh=fTSVxdrf8OhIbrziogVAwdGdw8F8G71uMVxS1m6mgHc=; b=vSxLMy0yATglfyW/UXTFZg8TjbEtm32qKvnLF/nl5cNibhzwIb3Xid9Fla7SGEkr7Toz ubRJ//JuOI1tL/IIsM15z7yFcq4OHlEW21YXHOnM/E5eCH/KXIL57mtdM6XMeEl4Qm7l xTqcHhGGM8EZff0XmfBVLybQH7eNXtVaL88/rXPcYgg1ndepc5l20LHsZzVO8ScF+UbK ZNn9Xx782LsFK8SGpbCdacyijLI+owdqFOkOvmciMLhlBfQMpeMlVRUO6uXBR9Hi44DJ 9q5kTJNKX/ZLbIF8zaNsgFbvIPsMIQJ37O9Z5NJwD8Zb0kmH1N7j7X8o42d2IvLormNh 1g== Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by userp2120.oracle.com with ESMTP id 2q3vhrq2y6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 23 Jan 2019 02:31:22 +0000 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id x0N2VKSS021764 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 23 Jan 2019 02:31:21 GMT Received: from abhmp0008.oracle.com (abhmp0008.oracle.com [141.146.116.14]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x0N2VJjA007417; Wed, 23 Jan 2019 02:31:20 GMT Received: from jw-M900.cn.oracle.com (/10.182.69.163) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 22 Jan 2019 18:31:19 -0800 From: Jacob Wen To: netdev@vger.kernel.org Cc: jchapman@katalix.com Subject: [PATCH net-next v1] l2tp: fix reading optional fields Date: Wed, 23 Jan 2019 10:30:50 +0800 Message-Id: <20190123023050.29062-1-jian.w.wen@oracle.com> X-Mailer: git-send-email 2.17.1 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9144 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1901230017 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Use pskb_may_pull() to make sure the optional fields are in skb linear parts. Signed-off-by: Jacob Wen --- v1: fix warning: ISO C90 forbids mixed declarations and code --- net/l2tp/l2tp_core.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 26f1d435696a..c0dfa2bcd218 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -627,6 +627,8 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, /* Parse and check optional cookie */ if (session->peer_cookie_len > 0) { + if (!pskb_may_pull(skb, ptr - optr + session->peer_cookie_len)) + goto discard; if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { l2tp_info(tunnel, L2TP_MSG_DATA, "%s: cookie mismatch (%u/%u). Discarding.\n", @@ -649,6 +651,8 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, L2TP_SKB_CB(skb)->has_seq = 0; if (tunnel->version == L2TP_HDR_VER_2) { if (hdrflags & L2TP_HDRFLAG_S) { + if (!pskb_may_pull(skb, ptr - optr + 4)) + goto discard; ns = ntohs(*(__be16 *) ptr); ptr += 2; nr = ntohs(*(__be16 *) ptr); @@ -663,8 +667,12 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, session->name, ns, nr, session->nr); } } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { - u32 l2h = ntohl(*(__be32 *) ptr); + u32 l2h; + + if (!pskb_may_pull(skb, ptr - optr + 4)) + goto discard; + l2h = ntohl(*(__be32 *) ptr); if (l2h & 0x40000000) { ns = l2h & 0x00ffffff; @@ -729,6 +737,8 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, if (tunnel->version == L2TP_HDR_VER_2) { /* If offset bit set, skip it. */ if (hdrflags & L2TP_HDRFLAG_O) { + if (!pskb_may_pull(skb, ptr - optr + 2)) + goto discard; offset = ntohs(*(__be16 *)ptr); ptr += 2 + offset; } -- 2.17.1