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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 41182C76194 for ; Sat, 27 Jul 2019 08:32:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 14D6F2085A for ; Sat, 27 Jul 2019 08:32:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728390AbfG0IcE (ORCPT ); Sat, 27 Jul 2019 04:32:04 -0400 Received: from a.mx.secunet.com ([62.96.220.36]:56232 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727466AbfG0IcD (ORCPT ); Sat, 27 Jul 2019 04:32:03 -0400 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id 776282019C; Sat, 27 Jul 2019 10:32:01 +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 fdzAf7cXfU0y; Sat, 27 Jul 2019 10:32:01 +0200 (CEST) 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 125E42018D; Sat, 27 Jul 2019 10:32:01 +0200 (CEST) Received: from gauss2.secunet.de (10.182.7.193) by mail-essen-01.secunet.de (10.53.40.204) with Microsoft SMTP Server id 14.3.468.0; Sat, 27 Jul 2019 10:32:00 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id ADF4D31803E0; Sat, 27 Jul 2019 10:32:00 +0200 (CEST) Date: Sat, 27 Jul 2019 10:32:00 +0200 From: Steffen Klassert To: Jeremy Sowden CC: Jia-Ju Bai , , , , Subject: Re: [PATCH] net: key: af_key: Fix possible null-pointer dereferences in pfkey_send_policy_notify() Message-ID: <20190727083200.GE14601@gauss3.secunet.de> References: <20190724093509.1676-1-baijiaju1990@gmail.com> <20190726094514.GD14601@gauss3.secunet.de> <20190726201555.GA4745@azazel.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20190726201555.GA4745@azazel.net> User-Agent: Mutt/1.9.4 (2018-02-28) 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 On Fri, Jul 26, 2019 at 09:15:55PM +0100, Jeremy Sowden wrote: > On 2019-07-26, at 11:45:14 +0200, Steffen Klassert wrote: > > On Wed, Jul 24, 2019 at 05:35:09PM +0800, Jia-Ju Bai wrote: > > > > > > diff --git a/net/key/af_key.c b/net/key/af_key.c > > > index b67ed3a8486c..ced54144d5fd 100644 > > > --- a/net/key/af_key.c > > > +++ b/net/key/af_key.c > > > @@ -3087,6 +3087,8 @@ static int pfkey_send_policy_notify(struct xfrm_policy *xp, int dir, const struc > > > case XFRM_MSG_DELPOLICY: > > > case XFRM_MSG_NEWPOLICY: > > > case XFRM_MSG_UPDPOLICY: > > > + if (!xp) > > > + break; > > > > I think this can not happen. Who sends one of these notifications > > without a pointer to the policy? > > I had a quick grep and found two places where km_policy_notify is passed > NULL as the policy: > > $ grep -rn '\ net/xfrm/xfrm_user.c:2154: km_policy_notify(NULL, 0, &c); > net/key/af_key.c:2788: km_policy_notify(NULL, 0, &c); > > They occur in xfrm_flush_policy() and pfkey_spdflush() respectively. Yes, but these two send a XFRM_MSG_FLUSHPOLICY notify. This does not trigger the code that is changed here.