From patchwork Fri May 29 11:04:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steffen Klassert X-Patchwork-Id: 218214 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, 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 C42F2C433DF for ; Fri, 29 May 2020 11:04:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A57172075A for ; Fri, 29 May 2020 11:04:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726695AbgE2LEV (ORCPT ); Fri, 29 May 2020 07:04:21 -0400 Received: from a.mx.secunet.com ([62.96.220.36]:39492 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726549AbgE2LEP (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 A7F9F205B4; Fri, 29 May 2020 13:04:14 +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 QMxQJiLi6AbS; Fri, 29 May 2020 13:04:14 +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 D991220539; 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 32BE03180607; Fri, 29 May 2020 13:04:12 +0200 (CEST) From: Steffen Klassert To: David Miller CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 09/15] xfrm: call xfrm_output_gso when inner_protocol is set in xfrm_output Date: Fri, 29 May 2020 13:04:02 +0200 Message-ID: <20200529110408.6349-10-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 X-ClientProxiedBy: cas-essen-01.secunet.de (10.53.40.201) 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 An use-after-free crash can be triggered when sending big packets over vxlan over esp with esp offload enabled: [] BUG: KASAN: use-after-free in ipv6_gso_pull_exthdrs.part.8+0x32c/0x4e0 [] Call Trace: [] dump_stack+0x75/0xa0 [] kasan_report+0x37/0x50 [] ipv6_gso_pull_exthdrs.part.8+0x32c/0x4e0 [] ipv6_gso_segment+0x2c8/0x13c0 [] skb_mac_gso_segment+0x1cb/0x420 [] skb_udp_tunnel_segment+0x6b5/0x1c90 [] inet_gso_segment+0x440/0x1380 [] skb_mac_gso_segment+0x1cb/0x420 [] esp4_gso_segment+0xae8/0x1709 [esp4_offload] [] inet_gso_segment+0x440/0x1380 [] skb_mac_gso_segment+0x1cb/0x420 [] __skb_gso_segment+0x2d7/0x5f0 [] validate_xmit_skb+0x527/0xb10 [] __dev_queue_xmit+0x10f8/0x2320 <--- [] ip_finish_output2+0xa2e/0x1b50 [] ip_output+0x1a8/0x2f0 [] xfrm_output_resume+0x110e/0x15f0 [] __xfrm4_output+0xe1/0x1b0 [] xfrm4_output+0xa0/0x200 [] iptunnel_xmit+0x5a7/0x920 [] vxlan_xmit_one+0x1658/0x37a0 [vxlan] [] vxlan_xmit+0x5e4/0x3ec8 [vxlan] [] dev_hard_start_xmit+0x125/0x540 [] __dev_queue_xmit+0x17bd/0x2320 <--- [] ip6_finish_output2+0xb20/0x1b80 [] ip6_output+0x1b3/0x390 [] ip6_xmit+0xb82/0x17e0 [] inet6_csk_xmit+0x225/0x3d0 [] __tcp_transmit_skb+0x1763/0x3520 [] tcp_write_xmit+0xd64/0x5fe0 [] __tcp_push_pending_frames+0x8c/0x320 [] tcp_sendmsg_locked+0x2245/0x3500 [] tcp_sendmsg+0x27/0x40 As on the tx path of vxlan over esp, skb->inner_network_header would be set on vxlan_xmit() and xfrm4_tunnel_encap_add(), and the later one can overwrite the former one. It causes skb_udp_tunnel_segment() to use a wrong skb->inner_network_header, then the issue occurs. This patch is to fix it by calling xfrm_output_gso() instead when the inner_protocol is set, in which gso_segment of inner_protocol will be done first. While at it, also improve some code around. Fixes: 7862b4058b9f ("esp: Add gso handlers for esp4 and esp6") Reported-by: Xiumei Mu Signed-off-by: Xin Long Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_output.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c index 2fd3d990d992..69c33cab8f49 100644 --- a/net/xfrm/xfrm_output.c +++ b/net/xfrm/xfrm_output.c @@ -583,18 +583,20 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb) xfrm_state_hold(x); if (skb_is_gso(skb)) { - skb_shinfo(skb)->gso_type |= SKB_GSO_ESP; + if (skb->inner_protocol) + return xfrm_output_gso(net, sk, skb); - return xfrm_output2(net, sk, skb); + skb_shinfo(skb)->gso_type |= SKB_GSO_ESP; + goto out; } if (x->xso.dev && x->xso.dev->features & NETIF_F_HW_ESP_TX_CSUM) goto out; + } else { + if (skb_is_gso(skb)) + return xfrm_output_gso(net, sk, skb); } - if (skb_is_gso(skb)) - return xfrm_output_gso(net, sk, skb); - if (skb->ip_summed == CHECKSUM_PARTIAL) { err = skb_checksum_help(skb); if (err) {