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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 EF48DC7618B for ; Mon, 29 Jul 2019 08:03:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D225B20693 for ; Mon, 29 Jul 2019 08:03:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727442AbfG2IDo (ORCPT ); Mon, 29 Jul 2019 04:03:44 -0400 Received: from a.mx.secunet.com ([62.96.220.36]:51364 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727257AbfG2IDn (ORCPT ); Mon, 29 Jul 2019 04:03:43 -0400 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id A91E620251; Mon, 29 Jul 2019 10:03:42 +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 z3XHQg18Gcm1; Mon, 29 Jul 2019 10:03:42 +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 43F7220082; Mon, 29 Jul 2019 10:03:42 +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; Mon, 29 Jul 2019 10:03:41 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id D9F5231805DA; Mon, 29 Jul 2019 10:03:41 +0200 (CEST) Date: Mon, 29 Jul 2019 10:03:41 +0200 From: Steffen Klassert To: Jia-Ju Bai CC: , , , Subject: Re: [BUG] net: xfrm: possible null-pointer dereferences in xfrm_policy() Message-ID: <20190729080341.GJ2879@gauss3.secunet.de> References: <464bb93d-75b2-c21b-ee32-25a10ff61622@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <464bb93d-75b2-c21b-ee32-25a10ff61622@gmail.com> 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 Mon, Jul 29, 2019 at 11:43:49AM +0800, Jia-Ju Bai wrote: > In xfrm_policy(), the while loop on lines 3802-3830 ends when dst->xfrm is > NULL. We don't have a xfrm_policy() function, and as said already the line numbers does not help much as long as you don't say which tree/branch this is and which commit is the head commit. > Then, dst->xfrm is used on line 3840: >     xfrm_state_mtu(dst->xfrm, mtu); >         if (x->km.state != XFRM_STATE_VALID...) >         aead = x->data; > > Thus, possible null-pointer dereferences may occur. I guess you refer to xfrm_bundle_ok(). The dst pointer is reoaded after the loop, so the dereferenced pointer is not the one that had NULL at dst->xfrm. > > These bugs are found by a static analysis tool STCheck written by us. > > I do not know how to correctly fix these bugs, so I only report them. I'd suggest you to manually review the reports of your tool and to fix the tool accordingly.