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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 28049C282D7 for ; Wed, 30 Jan 2019 11:33:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0068820989 for ; Wed, 30 Jan 2019 11:33:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730631AbfA3Lda (ORCPT ); Wed, 30 Jan 2019 06:33:30 -0500 Received: from a.mx.secunet.com ([62.96.220.36]:56690 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727136AbfA3Lda (ORCPT ); Wed, 30 Jan 2019 06:33:30 -0500 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id 40E87201BB; Wed, 30 Jan 2019 12:33:29 +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 kSEjxASE4bTr; Wed, 30 Jan 2019 12:33:28 +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 D4613200BD; Wed, 30 Jan 2019 12:33:28 +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 14.3.435.0; Wed, 30 Jan 2019 12:33:28 +0100 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 5EB0C318056A; Wed, 30 Jan 2019 12:33:28 +0100 (CET) Date: Wed, 30 Jan 2019 12:33:28 +0100 From: Steffen Klassert To: Martin Willi CC: Subject: Re: [PATCH] esp: Skip TX bytes accounting when sending from a request socket Message-ID: <20190130113328.GJ3581@gauss3.secunet.de> References: <20190128083535.18006-1-martin@strongswan.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20190128083535.18006-1-martin@strongswan.org> User-Agent: Mutt/1.9.4 (2018-02-28) 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: CFA41C85-C8D9-49EB-A7EC-AB12C9021B55 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 On Mon, Jan 28, 2019 at 09:35:35AM +0100, Martin Willi wrote: > 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 Applied, thanks Martin!