From patchwork Mon Dec 7 09:39:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steffen Klassert X-Patchwork-Id: 1411950 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=secunet.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CqJcD6FmVz9sW1 for ; Mon, 7 Dec 2020 20:56:28 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726798AbgLGJ4Q (ORCPT ); Mon, 7 Dec 2020 04:56:16 -0500 Received: from a.mx.secunet.com ([62.96.220.36]:49446 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726777AbgLGJ4N (ORCPT ); Mon, 7 Dec 2020 04:56:13 -0500 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id B66E92027C; Mon, 7 Dec 2020 10:55:31 +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 jt5oPFuYOvnG; Mon, 7 Dec 2020 10:55:27 +0100 (CET) Received: from cas-essen-02.secunet.de (unknown [10.53.40.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id 5A4872049A; Mon, 7 Dec 2020 10:55:27 +0100 (CET) Received: from mbx-essen-01.secunet.de (10.53.40.197) by cas-essen-02.secunet.de (10.53.40.202) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Mon, 7 Dec 2020 10:55:27 +0100 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 15.1.2044.4; Mon, 7 Dec 2020 10:55:26 +0100 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 97C1D3182E67; Mon, 7 Dec 2020 10:39:43 +0100 (CET) From: Steffen Klassert To: David Miller , Jakub Kicinski CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 1/4] xfrm/compat: Translate by copying XFRMA_UNSPEC attribute Date: Mon, 7 Dec 2020 10:39:34 +0100 Message-ID: <20201207093937.2874932-2-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201207093937.2874932-1-steffen.klassert@secunet.com> References: <20201207093937.2874932-1-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 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Dmitry Safonov xfrm_xlate32() translates 64-bit message provided by kernel to be sent for 32-bit listener (acknowledge or monitor). Translator code doesn't expect XFRMA_UNSPEC attribute as it doesn't know its payload. Kernel never attaches such attribute, but a user can. I've searched if any opensource does it and the answer is no. Nothing on github and google finds only tfcproject that has such code commented-out. What will happen if a user sends a netlink message with XFRMA_UNSPEC attribute? Ipsec code ignores this attribute. But if there is a monitor-process or 32-bit user requested ack - kernel will try to translate such message and will hit WARN_ONCE() in xfrm_xlate64_attr(). Deal with XFRMA_UNSPEC by copying the attribute payload with xfrm_nla_cpy(). In result, the default switch-case in xfrm_xlate64_attr() becomes an unused code. Leave those 3 lines in case a new xfrm attribute will be added. Fixes: 5461fc0c8d9f ("xfrm/compat: Add 64=>32-bit messages translator") Reported-by: syzbot+a7e701c8385bd8543074@syzkaller.appspotmail.com Signed-off-by: Dmitry Safonov Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_compat.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/xfrm/xfrm_compat.c b/net/xfrm/xfrm_compat.c index e28f0c9ecd6a..17edbf935e35 100644 --- a/net/xfrm/xfrm_compat.c +++ b/net/xfrm/xfrm_compat.c @@ -234,6 +234,7 @@ static int xfrm_xlate64_attr(struct sk_buff *dst, const struct nlattr *src) case XFRMA_PAD: /* Ignore */ return 0; + case XFRMA_UNSPEC: case XFRMA_ALG_AUTH: case XFRMA_ALG_CRYPT: case XFRMA_ALG_COMP: