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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 7940DC433E0 for ; Fri, 29 May 2020 11:04:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5D61D2075A for ; Fri, 29 May 2020 11:04:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726649AbgE2LEU (ORCPT ); Fri, 29 May 2020 07:04:20 -0400 Received: from a.mx.secunet.com ([62.96.220.36]:39478 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725939AbgE2LEP (ORCPT ); Fri, 29 May 2020 07:04:15 -0400 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id F0FF5205E3; Fri, 29 May 2020 13:04:13 +0200 (CEST) X-Virus-Scanned: by secunet Received: from a.mx.secunet.com ([127.0.0.1]) by localhost (a.mx.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id TTmh8bf4upNb; Fri, 29 May 2020 13:04:13 +0200 (CEST) Received: from mail-essen-01.secunet.de (mail-essen-01.secunet.de [10.53.40.204]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id 78EDB205CF; Fri, 29 May 2020 13:04:13 +0200 (CEST) Received: from mbx-essen-01.secunet.de (10.53.40.197) by mail-essen-01.secunet.de (10.53.40.204) with Microsoft SMTP Server (TLS) id 14.3.487.0; Fri, 29 May 2020 13:04:13 +0200 Received: from gauss2.secunet.de (10.182.7.193) by mbx-essen-01.secunet.de (10.53.40.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Fri, 29 May 2020 13:04:12 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 13A2D3180266; Fri, 29 May 2020 13:04:12 +0200 (CEST) From: Steffen Klassert To: David Miller CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 02/15] xfrm: do pskb_pull properly in __xfrm_transport_prep Date: Fri, 29 May 2020 13:03:55 +0200 Message-ID: <20200529110408.6349-3-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200529110408.6349-1-steffen.klassert@secunet.com> References: <20200529110408.6349-1-steffen.klassert@secunet.com> MIME-Version: 1.0 Content-Type: text/plain X-ClientProxiedBy: cas-essen-02.secunet.de (10.53.40.202) To mbx-essen-01.secunet.de (10.53.40.197) X-EXCLAIMER-MD-CONFIG: 2c86f778-e09b-4440-8b15-867914633a10 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Xin Long For transport mode, when ipv6 nexthdr is set, the packet format might be like: ---------------------------------------------------- | | dest | | | | ESP | ESP | | IP6 hdr| opts.| ESP | TCP | Data | Trailer | ICV | ---------------------------------------------------- and in __xfrm_transport_prep(): pskb_pull(skb, skb->mac_len + sizeof(ip6hdr) + x->props.header_len); it will pull the data pointer to the wrong position, as it missed the nexthdrs/dest opts. This patch is to fix it by using: pskb_pull(skb, skb_transport_offset(skb) + x->props.header_len); as we can be sure transport_header points to ESP header at that moment. It also fixes a panic when packets with ipv6 nexthdr are sent over esp6 transport mode: [ 100.473845] kernel BUG at net/core/skbuff.c:4325! [ 100.478517] RIP: 0010:__skb_to_sgvec+0x252/0x260 [ 100.494355] Call Trace: [ 100.494829] skb_to_sgvec+0x11/0x40 [ 100.495492] esp6_output_tail+0x12e/0x550 [esp6] [ 100.496358] esp6_xmit+0x1d5/0x260 [esp6_offload] [ 100.498029] validate_xmit_xfrm+0x22f/0x2e0 [ 100.499604] __dev_queue_xmit+0x589/0x910 [ 100.502928] ip6_finish_output2+0x2a5/0x5a0 [ 100.503718] ip6_output+0x6c/0x120 [ 100.505198] xfrm_output_resume+0x4bf/0x530 [ 100.508683] xfrm6_output+0x3a/0xc0 [ 100.513446] inet6_csk_xmit+0xa1/0xf0 [ 100.517335] tcp_sendmsg+0x27/0x40 [ 100.517977] sock_sendmsg+0x3e/0x60 [ 100.518648] __sys_sendto+0xee/0x160 Fixes: c35fe4106b92 ("xfrm: Add mode handlers for IPsec on layer 2") Signed-off-by: Xin Long Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_device.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c index 6cc7f7f1dd68..f50d1f97cf8e 100644 --- a/net/xfrm/xfrm_device.c +++ b/net/xfrm/xfrm_device.c @@ -25,12 +25,10 @@ static void __xfrm_transport_prep(struct xfrm_state *x, struct sk_buff *skb, struct xfrm_offload *xo = xfrm_offload(skb); skb_reset_mac_len(skb); - pskb_pull(skb, skb->mac_len + hsize + x->props.header_len); - - if (xo->flags & XFRM_GSO_SEGMENT) { - skb_reset_transport_header(skb); + if (xo->flags & XFRM_GSO_SEGMENT) skb->transport_header -= x->props.header_len; - } + + pskb_pull(skb, skb_transport_offset(skb) + x->props.header_len); } static void __xfrm_mode_tunnel_prep(struct xfrm_state *x, struct sk_buff *skb, -- 2.17.1