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 0260FC001E0 for ; Mon, 31 Jul 2023 01:46:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229661AbjGaBqr (ORCPT ); Sun, 30 Jul 2023 21:46:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229478AbjGaBqp (ORCPT ); Sun, 30 Jul 2023 21:46:45 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61D9BE57; Sun, 30 Jul 2023 18:46:43 -0700 (PDT) Received: from dggpemm500016.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4RDgxJ1NhKzNmNT; Mon, 31 Jul 2023 09:43:16 +0800 (CST) Received: from [10.67.110.48] (10.67.110.48) by dggpemm500016.china.huawei.com (7.185.36.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Mon, 31 Jul 2023 09:46:40 +0800 Message-ID: Date: Mon, 31 Jul 2023 09:46:34 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH v2 5/9] selinux: services: update type for number of class permissions To: =?UTF-8?Q?Christian_G=c3=b6ttsche?= , CC: Paul Moore , Stephen Smalley , Eric Paris , Ondrej Mosnacek , References: <20230728155501.39632-1-cgzones@googlemail.com> <20230728155501.39632-4-cgzones@googlemail.com> Content-Language: en-US From: Gong Ruiqi In-Reply-To: <20230728155501.39632-4-cgzones@googlemail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.110.48] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500016.china.huawei.com (7.185.36.25) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/07/28 23:54, Christian Göttsche wrote: > Security classes have only up to 32 permissions, hence using an u16 is > sufficient (while improving padding in struct selinux_mapping). > > Also use a fixed sized cast in a bit shift to avoid (well defined) > overflows on architectures where sizeof(unsigned int) != sizeof(u32) > resulting in no bits set. > > Signed-off-by: Christian Göttsche Reviewed-by: GONG, Ruiqi > --- > v2: > update commit description: > - mention struct selinux_mapping in the padding argument > (currently between the first and second member there are 2 bytes > padding) > - mention overflow in the cast argument and the result of setting > no bits due to it > --- > security/selinux/ss/services.c | 6 +++--- > security/selinux/ss/services.h | 2 +- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c > index 2c5be06fbada..cf4b87ec4a0e 100644 > --- a/security/selinux/ss/services.c > +++ b/security/selinux/ss/services.c > @@ -97,7 +97,6 @@ static int selinux_set_mapping(struct policydb *pol, > struct selinux_map *out_map) > { > u16 i, j; > - unsigned k; > bool print_unknown_handle = false; > > /* Find number of classes in the input mapping */ > @@ -117,6 +116,7 @@ static int selinux_set_mapping(struct policydb *pol, > while (map[j].name) { > const struct security_class_mapping *p_in = map + (j++); > struct selinux_mapping *p_out = out_map->mapping + j; > + u16 k; > > /* An empty class string skips ahead */ > if (!strcmp(p_in->name, "")) { > @@ -202,7 +202,7 @@ static void map_decision(struct selinux_map *map, > { > if (tclass < map->size) { > struct selinux_mapping *mapping = &map->mapping[tclass]; > - unsigned int i, n = mapping->num_perms; > + u16 i, n = mapping->num_perms; > u32 result; > > for (i = 0, result = 0; i < n; i++) { > @@ -230,7 +230,7 @@ static void map_decision(struct selinux_map *map, > * should audit that denial > */ > for (; i < (sizeof(u32)*8); i++) > - result |= 1< + result |= 1<<((u32)i); > avd->auditdeny = result; > } > } > diff --git a/security/selinux/ss/services.h b/security/selinux/ss/services.h > index ed2ee6600467..d24b0a3d198e 100644 > --- a/security/selinux/ss/services.h > +++ b/security/selinux/ss/services.h > @@ -12,7 +12,7 @@ > /* Mapping for a single class */ > struct selinux_mapping { > u16 value; /* policy value for class */ > - unsigned int num_perms; /* number of permissions in class */ > + u16 num_perms; /* number of permissions in class */ > u32 perms[sizeof(u32) * 8]; /* policy values for permissions */ > }; >