From patchwork Tue Mar 23 08:26:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steffen Klassert X-Patchwork-Id: 407419 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS 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 CC5CBC433E0 for ; Tue, 23 Mar 2021 08:27:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1A4B619B9 for ; Tue, 23 Mar 2021 08:27:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229920AbhCWI0y (ORCPT ); Tue, 23 Mar 2021 04:26:54 -0400 Received: from a.mx.secunet.com ([62.96.220.36]:49644 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229448AbhCWI0r (ORCPT ); Tue, 23 Mar 2021 04:26:47 -0400 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id 8D5B4201CF for ; Tue, 23 Mar 2021 09:26:45 +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 bHzqpAVuQyNz for ; Tue, 23 Mar 2021 09:26:45 +0100 (CET) Received: from cas-essen-01.secunet.de (unknown [10.53.40.201]) (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 1F00020184 for ; Tue, 23 Mar 2021 09:26:45 +0100 (CET) Received: from mbx-essen-01.secunet.de (10.53.40.197) by cas-essen-01.secunet.de (10.53.40.201) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Tue, 23 Mar 2021 09:26:45 +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 15.1.2176.2; Tue, 23 Mar 2021 09:26:44 +0100 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 470433180449; Tue, 23 Mar 2021 09:26:44 +0100 (CET) Date: Tue, 23 Mar 2021 09:26:44 +0100 From: Steffen Klassert To: Subject: [PATCH ipsec] xfrm: Fix NULL pointer dereference on policy lookup Message-ID: <20210323082644.GP62598@gauss3.secunet.de> MIME-Version: 1.0 Content-Disposition: inline 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 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When xfrm interfaces are used in combination with namespaces and ESP offload, we get a dst_entry NULL pointer dereference. This is because we don't have a dst_entry attached in the ESP offloading case and we need to do a policy lookup before the namespace transition. Fix this by expicit checking of skb_dst(skb) before accessing it. Fixes: f203b76d78092 ("xfrm: Add virtual xfrm interfaces") Signed-off-by: Steffen Klassert --- include/net/xfrm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/xfrm.h b/include/net/xfrm.h index b2a06f10b62c..fdb7e40a61e9 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -1097,7 +1097,7 @@ static inline int __xfrm_policy_check2(struct sock *sk, int dir, return __xfrm_policy_check(sk, ndir, skb, family); return (!net->xfrm.policy_count[dir] && !secpath_exists(skb)) || - (skb_dst(skb)->flags & DST_NOPOLICY) || + (skb_dst(skb) && (skb_dst(skb)->flags & DST_NOPOLICY)) || __xfrm_policy_check(sk, ndir, skb, family); }