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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 5AACAC43381 for ; Thu, 21 Feb 2019 08:22:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2F6D120818 for ; Thu, 21 Feb 2019 08:22:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727321AbfBUIWN (ORCPT ); Thu, 21 Feb 2019 03:22:13 -0500 Received: from a.mx.secunet.com ([62.96.220.36]:59190 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725978AbfBUIWL (ORCPT ); Thu, 21 Feb 2019 03:22:11 -0500 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id D56C120279; Thu, 21 Feb 2019 09:22:09 +0100 (CET) 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 OsEHGUbBtSIZ; Thu, 21 Feb 2019 09:22:09 +0100 (CET) Received: from mail-essen-01.secunet.de (mail-essen-01.secunet.de [10.53.40.204]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id 3AEFA2025C; Thu, 21 Feb 2019 09:22:08 +0100 (CET) Received: from gauss2.secunet.de (10.182.7.193) by mail-essen-01.secunet.de (10.53.40.204) with Microsoft SMTP Server id 14.3.439.0; Thu, 21 Feb 2019 09:22:07 +0100 Received: by gauss2.secunet.de (Postfix, from userid 1000) id C85D43182607; Thu, 21 Feb 2019 09:22:06 +0100 (CET) From: Steffen Klassert To: David Miller CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 1/4] esp: Skip TX bytes accounting when sending from a request socket Date: Thu, 21 Feb 2019 09:22:01 +0100 Message-ID: <20190221082204.10134-2-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190221082204.10134-1-steffen.klassert@secunet.com> References: <20190221082204.10134-1-steffen.klassert@secunet.com> MIME-Version: 1.0 Content-Type: text/plain X-G-Data-MailSecurity-for-Exchange-State: 0 X-G-Data-MailSecurity-for-Exchange-Error: 0 X-G-Data-MailSecurity-for-Exchange-Sender: 23 X-G-Data-MailSecurity-for-Exchange-Server: d65e63f7-5c15-413f-8f63-c0d707471c93 X-EXCLAIMER-MD-CONFIG: 2c86f778-e09b-4440-8b15-867914633a10 X-G-Data-MailSecurity-for-Exchange-Guid: 7C74EE2C-2A23-43CC-A879-2D9E2350E89D X-G-Data-MailSecurity-for-Exchange-ProcessedOnRouted: True Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Martin Willi On ESP output, sk_wmem_alloc is incremented for the added padding if a socket is associated to the skb. When replying with TCP SYNACKs over IPsec, the associated sk is a casted request socket, only. Increasing sk_wmem_alloc on a request socket results in a write at an arbitrary struct offset. In the best case, this produces the following WARNING: WARNING: CPU: 1 PID: 0 at lib/refcount.c:102 esp_output_head+0x2e4/0x308 [esp4] refcount_t: addition on 0; use-after-free. CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.0.0-rc3 #2 Hardware name: Marvell Armada 380/385 (Device Tree) [...] [] (esp_output_head [esp4]) from [] (esp_output+0xb8/0x180 [esp4]) [] (esp_output [esp4]) from [] (xfrm_output_resume+0x558/0x664) [] (xfrm_output_resume) from [] (xfrm4_output+0x44/0xc4) [] (xfrm4_output) from [] (tcp_v4_send_synack+0xa8/0xe8) [] (tcp_v4_send_synack) from [] (tcp_conn_request+0x7f4/0x948) [] (tcp_conn_request) from [] (tcp_rcv_state_process+0x2a0/0xe64) [] (tcp_rcv_state_process) from [] (tcp_v4_do_rcv+0xf0/0x1f4) [] (tcp_v4_do_rcv) from [] (tcp_v4_rcv+0xdb8/0xe20) [] (tcp_v4_rcv) from [] (ip_protocol_deliver_rcu+0x2c/0x2dc) [] (ip_protocol_deliver_rcu) from [] (ip_local_deliver_finish+0x48/0x54) [] (ip_local_deliver_finish) from [] (ip_local_deliver+0x54/0xec) [] (ip_local_deliver) from [] (ip_rcv+0x48/0xb8) [] (ip_rcv) from [] (__netif_receive_skb_one_core+0x50/0x6c) [...] The issue triggers only when not using TCP syncookies, as for syncookies no socket is associated. Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible") Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible") Signed-off-by: Martin Willi Signed-off-by: Steffen Klassert --- net/ipv4/esp4.c | 2 +- net/ipv6/esp6.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index 5459f41fc26f..10e809b296ec 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -328,7 +328,7 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info * skb->len += tailen; skb->data_len += tailen; skb->truesize += tailen; - if (sk) + if (sk && sk_fullsock(sk)) refcount_add(tailen, &sk->sk_wmem_alloc); goto out; diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index 5afe9f83374d..239d4a65ad6e 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -296,7 +296,7 @@ int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info skb->len += tailen; skb->data_len += tailen; skb->truesize += tailen; - if (sk) + if (sk && sk_fullsock(sk)) refcount_add(tailen, &sk->sk_wmem_alloc); goto out; -- 2.17.1