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 3FCCFC433EF for ; Mon, 11 Jul 2022 08:16:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229478AbiGKIQo (ORCPT ); Mon, 11 Jul 2022 04:16:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54328 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229463AbiGKIQn (ORCPT ); Mon, 11 Jul 2022 04:16:43 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 752B61D32B; Mon, 11 Jul 2022 01:16:41 -0700 (PDT) Received: from fraeml715-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4LhGnv6hPCz67xNM; Mon, 11 Jul 2022 16:12:19 +0800 (CST) Received: from lhreml745-chm.china.huawei.com (10.201.108.195) by fraeml715-chm.china.huawei.com (10.206.15.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 11 Jul 2022 10:16:39 +0200 Received: from [10.122.132.241] (10.122.132.241) by lhreml745-chm.china.huawei.com (10.201.108.195) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 11 Jul 2022 09:16:38 +0100 Message-ID: <88cd33f2-8c6c-bfff-7271-7508b1ebac17@huawei.com> Date: Mon, 11 Jul 2022 11:16:37 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.4.1 Subject: Re: [PATCH v6 02/17] landlock: refactors landlock_find/insert_rule Content-Language: ru To: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= CC: , , , , , References: <20220621082313.3330667-1-konstantin.meskhidze@huawei.com> <20220621082313.3330667-3-konstantin.meskhidze@huawei.com> <0bbbcf21-1e7d-5585-545f-bf89d8ebd527@digikod.net> <9d0c8780-6648-404f-7e51-b62a36617121@huawei.com> <72375435-94d4-e3aa-c27b-b44382dde6ad@digikod.net> <76c7c92e-3377-0bb8-14d5-e5c286c67dc3@huawei.com> <7d72fc3e-bdeb-14b8-1e6c-a99c2d052e3f@digikod.net> From: "Konstantin Meskhidze (A)" In-Reply-To: <7d72fc3e-bdeb-14b8-1e6c-a99c2d052e3f@digikod.net> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.122.132.241] X-ClientProxiedBy: lhreml752-chm.china.huawei.com (10.201.108.202) To lhreml745-chm.china.huawei.com (10.201.108.195) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 7/8/2022 7:57 PM, Mickaël Salaün пишет: > > On 08/07/2022 16:20, Konstantin Meskhidze (A) wrote: >> >> >> 7/8/2022 4:56 PM, Mickaël Salaün пишет: >>> >>> On 08/07/2022 14:53, Konstantin Meskhidze (A) wrote: >>>> >>>> >>>> 7/7/2022 7:44 PM, Mickaël Salaün пишет: >>>>> >>>>> On 21/06/2022 10:22, Konstantin Meskhidze wrote: >>>>>> Adds a new object union to support a socket port >>>>>> rule type. Refactors landlock_insert_rule() and >>>>>> landlock_find_rule() to support coming network >>>>>> modifications. Now adding or searching a rule >>>>>> in a ruleset depends on a rule_type argument >>>>>> provided in refactored functions mentioned above. >>>>>> >>>>>> Signed-off-by: Konstantin Meskhidze >>>>>> --- >>>>>> >>>>>> Changes since v5: >>>>>> * Formats code with clang-format-14. >>>>>> >>>>>> Changes since v4: >>>>>> * Refactors insert_rule() and create_rule() functions by deleting >>>>>> rule_type from their arguments list, it helps to reduce useless code. >>>>>> >>>>>> Changes since v3: >>>>>> * Splits commit. >>>>>> * Refactors landlock_insert_rule and landlock_find_rule functions. >>>>>> * Rename new_ruleset->root_inode. >>>>>> >>>>>> --- >>>>>>   security/landlock/fs.c      |   7 ++- >>>>>>   security/landlock/ruleset.c | 105 >>>>>> ++++++++++++++++++++++++++---------- >>>>>>   security/landlock/ruleset.h |  27 +++++----- >>>>>>   3 files changed, 96 insertions(+), 43 deletions(-) >>>>>> >>>>>> diff --git a/security/landlock/fs.c b/security/landlock/fs.c >>>>>> index e6da08ed99d1..46aedc2a05a8 100644 >>>>>> --- a/security/landlock/fs.c >>>>>> +++ b/security/landlock/fs.c >>>>>> @@ -173,7 +173,8 @@ int landlock_append_fs_rule(struct >>>>>> landlock_ruleset *const ruleset, >>>>>>       if (IS_ERR(object)) >>>>>>           return PTR_ERR(object); >>>>>>       mutex_lock(&ruleset->lock); >>>>>> -    err = landlock_insert_rule(ruleset, object, access_rights); >>>>>> +    err = landlock_insert_rule(ruleset, object, 0, access_rights, >>>>>> +                   LANDLOCK_RULE_PATH_BENEATH); >>>>>>       mutex_unlock(&ruleset->lock); >>>>>>       /* >>>>>>        * No need to check for an error because landlock_insert_rule() >>>>>> @@ -204,7 +205,9 @@ find_rule(const struct landlock_ruleset *const >>>>>> domain, >>>>>>       inode = d_backing_inode(dentry); >>>>>>       rcu_read_lock(); >>>>>>       rule = landlock_find_rule( >>>>>> -        domain, rcu_dereference(landlock_inode(inode)->object)); >>>>>> +        domain, >>>>>> +        (uintptr_t)rcu_dereference(landlock_inode(inode)->object), >>>>>> +        LANDLOCK_RULE_PATH_BENEATH); >>>>>>       rcu_read_unlock(); >>>>>>       return rule; >>>>>>   } >>>>>> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c >>>>>> index a3fd58d01f09..5f13f8a12aee 100644 >>>>>> --- a/security/landlock/ruleset.c >>>>>> +++ b/security/landlock/ruleset.c >>>>>> @@ -35,7 +35,7 @@ static struct landlock_ruleset >>>>>> *create_ruleset(const u32 num_layers) >>>>>>           return ERR_PTR(-ENOMEM); >>>>>>       refcount_set(&new_ruleset->usage, 1); >>>>>>       mutex_init(&new_ruleset->lock); >>>>>> -    new_ruleset->root = RB_ROOT; >>>>>> +    new_ruleset->root_inode = RB_ROOT; >>>>>>       new_ruleset->num_layers = num_layers; >>>>>>       /* >>>>>>        * hierarchy = NULL >>>>>> @@ -69,7 +69,8 @@ static void build_check_rule(void) >>>>>>   } >>>>>> >>>>>>   static struct landlock_rule * >>>>>> -create_rule(struct landlock_object *const object, >>>>>> +create_rule(struct landlock_object *const object_ptr, >>>>>> +        const uintptr_t object_data, >>>>>>           const struct landlock_layer (*const layers)[], const u32 >>>>>> num_layers, >>>>>>           const struct landlock_layer *const new_layer) >>>>>>   { >>>>>> @@ -90,8 +91,15 @@ create_rule(struct landlock_object *const object, >>>>>>       if (!new_rule) >>>>>>           return ERR_PTR(-ENOMEM); >>>>>>       RB_CLEAR_NODE(&new_rule->node); >>>>>> -    landlock_get_object(object); >>>>>> -    new_rule->object = object; >>>>>> + >>>>>> +    if (object_ptr) { >>>>>> +        landlock_get_object(object_ptr); >>>>>> +        new_rule->object.ptr = object_ptr; >>>>>> +    } else if (object_ptr && object_data) { >>>>> >>>>> Something is wrong with this second check: else + object_ptr? >>>> >>>> It was your suggestion to use it like this: >>>> " ....You can also add a WARN_ON_ONCE(object_ptr && object_data)." >>>> >>>> Please check it here: >>>> https://lore.kernel.org/linux-security-module/bc44f11f-0eaa-a5f6-c5dc-1d36570f1be1@digikod.net/ >>> >>> >>> Yes, but the error is in the "else", you should write: >>> if (WARN_ON_ONCE(object_ptr && object_data)) >>>     return ERR_PTR(-EINVAL); >>> >>> …and this should be before the `if (object_ptr) {` line (to avoid >>> erronous landlock_get_object() call), just after the `if (!new_rule)` >>> check. Ok. I got it. >> >>   Maybe we could delete this check here cause we have it in the upper >> insert_rule() function?? >> >> ... >>     if (WARN_ON_ONCE(!layers)) >>         return -ENOENT; >> ------>    if (WARN_ON_ONCE(object_ptr && object_data)) >>         return -EINVAL; >>     /* Chooses rb_tree structure depending on a rule type. */ >>     switch (rule_type) { >>     case LANDLOCK_RULE_PATH_BENEATH: >>         if (WARN_ON_ONCE(!object_ptr)) >>             return -ENOENT; >>         object_data = (uintptr_t)object_ptr; >>         root = &ruleset->root_inode; >>         break; >>     default: >>         WARN_ON_ONCE(1); >>         return -EINVAL; >>     } >> ... >> >> This is double check here. What do you think? > > This check is indeed done twice, and for now create_rule() is only > called from insert_rule(), but I prefer to keep it in both location to > not get bitten in the future were it could be called from other > locations. The compiler may be smart enough to remove the redundant > checks though. > > I'll send a patch to improve this part. Ok. thanks!!! > .