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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55956C433EF for ; Sat, 4 Jun 2022 07:40:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233114AbiFDHkK (ORCPT ); Sat, 4 Jun 2022 03:40:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230074AbiFDHkG (ORCPT ); Sat, 4 Jun 2022 03:40:06 -0400 Received: from a.mx.secunet.com (a.mx.secunet.com [62.96.220.36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21DE9275E6; Sat, 4 Jun 2022 00:40:05 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id 1989B2055E; Sat, 4 Jun 2022 09:40:03 +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 jHU0zutdV4mI; Sat, 4 Jun 2022 09:40:02 +0200 (CEST) Received: from mailout2.secunet.com (mailout2.secunet.com [62.96.220.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id 9E1D120322; Sat, 4 Jun 2022 09:40:02 +0200 (CEST) Received: from cas-essen-01.secunet.de (unknown [10.53.40.201]) by mailout2.secunet.com (Postfix) with ESMTP id 8DF3D80004A; Sat, 4 Jun 2022 09:40:02 +0200 (CEST) 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 15.1.2375.24; Sat, 4 Jun 2022 09:40:02 +0200 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 15.1.2375.24; Sat, 4 Jun 2022 09:40:02 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id D343B3182D6B; Sat, 4 Jun 2022 09:40:01 +0200 (CEST) Date: Sat, 4 Jun 2022 09:40:01 +0200 From: Steffen Klassert To: Hangyu Hua CC: , , , , , , , Subject: Re: [PATCH v2] xfrm: xfrm_policy: fix a possible double xfrm_pols_put() in xfrm_bundle_lookup() Message-ID: <20220604074001.GL680067@gauss3.secunet.de> References: <20220601064625.26414-1-hbh25y@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20220601064625.26414-1-hbh25y@gmail.com> 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: linux-kernel@vger.kernel.org On Wed, Jun 01, 2022 at 02:46:25PM +0800, Hangyu Hua wrote: > xfrm_policy_lookup() will call xfrm_pol_hold_rcu() to get a refcount of > pols[0]. This refcount can be dropped in xfrm_expand_policies() when > xfrm_expand_policies() return error. pols[0]'s refcount is balanced in > here. But xfrm_bundle_lookup() will also call xfrm_pols_put() with > num_pols == 1 to drop this refcount when xfrm_expand_policies() return > error. > > This patch also fix an illegal address access. pols[0] will save a error > point when xfrm_policy_lookup fails. This lead to xfrm_pols_put to resolve > an illegal address in xfrm_bundle_lookup's error path. > > Fix these by setting num_pols = 0 in xfrm_expand_policies()'s error path. > > Fixes: 80c802f3073e ("xfrm: cache bundles instead of policies for outgoing flows") > Signed-off-by: Hangyu Hua Applied, thanks!