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 531A4C47088 for ; Fri, 2 Dec 2022 02:49:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231631AbiLBCtu (ORCPT ); Thu, 1 Dec 2022 21:49:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230328AbiLBCts (ORCPT ); Thu, 1 Dec 2022 21:49:48 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD0C6A65B1; Thu, 1 Dec 2022 18:49:47 -0800 (PST) Received: from frapeml100003.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4NNcld4Psqz67L71; Fri, 2 Dec 2022 10:46:37 +0800 (CST) Received: from lhrpeml500004.china.huawei.com (7.191.163.9) by frapeml100003.china.huawei.com (7.182.85.60) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 2 Dec 2022 03:49:45 +0100 Received: from [10.122.132.241] (10.122.132.241) by lhrpeml500004.china.huawei.com (7.191.163.9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Fri, 2 Dec 2022 02:49:44 +0000 Message-ID: Date: Fri, 2 Dec 2022 05:49:43 +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 v8 01/12] landlock: Make ruleset's access masks more generic Content-Language: ru To: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= CC: , , , , , References: <20221021152644.155136-1-konstantin.meskhidze@huawei.com> <20221021152644.155136-2-konstantin.meskhidze@huawei.com> <94ed4212-c093-9c5c-089f-e9e4097e5bd6@digikod.net> <3f9fc69d-1604-d879-d341-8a831beabeea@huawei.com> <700956d7-9831-da1d-c397-d1fb45aaf5d7@digikod.net> From: "Konstantin Meskhidze (A)" In-Reply-To: <700956d7-9831-da1d-c397-d1fb45aaf5d7@digikod.net> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.122.132.241] X-ClientProxiedBy: lhrpeml500004.china.huawei.com (7.191.163.9) To lhrpeml500004.china.huawei.com (7.191.163.9) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 11/28/2022 11:22 PM, Mickaël Salaün пишет: > > On 28/11/2022 03:53, Konstantin Meskhidze (A) wrote: >> >> >> 11/17/2022 9:41 PM, Mickaël Salaün пишет: >>> >>> On 21/10/2022 17:26, Konstantin Meskhidze wrote: >>>> To support network type rules, this modification renames ruleset's >>>> access masks and modifies it's type to access_masks_t. This patch >>>> adds filesystem helper functions to add and get filesystem mask. >>>> >>>> Signed-off-by: Konstantin Meskhidze >>>> --- >>>> >>>> Changes since v7: >>>> * Refactors commit message. >>>> >>>> Changes since v6: >>>> * Adds a new access_masks_t for struct ruleset. >>>> * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() >>>> because it OR values. >>>> * Makes landlock_add_fs_access_mask() more resilient incorrect values. >>>> * Refactors landlock_get_fs_access_mask(). >>>> >>>> Changes since v6: >>>> * Adds a new access_masks_t for struct ruleset. >>>> * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() >>>> because it OR values. >>>> * Makes landlock_add_fs_access_mask() more resilient incorrect values. >>>> * Refactors landlock_get_fs_access_mask(). >>>> >>>> Changes since v5: >>>> * Changes access_mask_t to u32. >>>> * Formats code with clang-format-14. >>>> >>>> Changes since v4: >>>> * Deletes struct landlock_access_mask. >>>> >>>> Changes since v3: >>>> * Splits commit. >>>> * Adds get_mask, set_mask helpers for filesystem. >>>> * Adds new struct landlock_access_mask. >>>> >>>> --- >>>> security/landlock/fs.c | 10 +++++----- >>>> security/landlock/limits.h | 1 + >>>> security/landlock/ruleset.c | 17 +++++++++-------- >>>> security/landlock/ruleset.h | 35 +++++++++++++++++++++++++++++++---- >>>> security/landlock/syscalls.c | 7 ++++--- >>>> 5 files changed, 50 insertions(+), 20 deletions(-) >>>> >>>> diff --git a/security/landlock/fs.c b/security/landlock/fs.c >>>> index adcea0fe7e68..0d57c6479d29 100644 >>>> --- a/security/landlock/fs.c >>>> +++ b/security/landlock/fs.c >>>> @@ -178,9 +178,9 @@ int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, >>>> return -EINVAL; >>>> >>>> /* Transforms relative access rights to absolute ones. */ >>>> - access_rights |= >>>> - LANDLOCK_MASK_ACCESS_FS & >>>> - ~(ruleset->fs_access_masks[0] | ACCESS_INITIALLY_DENIED); >>>> + access_rights |= LANDLOCK_MASK_ACCESS_FS & >>>> + ~(landlock_get_fs_access_mask(ruleset, 0) | >>>> + ACCESS_INITIALLY_DENIED); >>>> object = get_inode_object(d_backing_inode(path->dentry)); >>>> if (IS_ERR(object)) >>>> return PTR_ERR(object); >>>> @@ -294,7 +294,7 @@ get_handled_accesses(const struct landlock_ruleset *const domain) >>>> size_t layer_level; >>>> >>>> for (layer_level = 0; layer_level < domain->num_layers; layer_level++) >>>> - access_dom |= domain->fs_access_masks[layer_level]; >>>> + access_dom |= landlock_get_fs_access_mask(domain, layer_level); >>>> return access_dom & LANDLOCK_MASK_ACCESS_FS; >>> >>> You can remove `& LANDLOCK_MASK_ACCESS_FS` here because it is now part >>> of landlock_get_fs_access_mask(). >> >> Ok. I got it. Thanks. >>> >>> >>>> } >>>> >>>> @@ -336,7 +336,7 @@ init_layer_masks(const struct landlock_ruleset *const domain, >>>> * access rights. >>>> */ >>>> if (BIT_ULL(access_bit) & >>>> - (domain->fs_access_masks[layer_level] | >>>> + (landlock_get_fs_access_mask(domain, layer_level) | >>>> ACCESS_INITIALLY_DENIED)) { >>>> (*layer_masks)[access_bit] |= >>>> BIT_ULL(layer_level); >>>> diff --git a/security/landlock/limits.h b/security/landlock/limits.h >>>> index 82288f0e9e5e..bafb3b8dc677 100644 >>>> --- a/security/landlock/limits.h >>>> +++ b/security/landlock/limits.h >>>> @@ -21,6 +21,7 @@ >>>> #define LANDLOCK_LAST_ACCESS_FS LANDLOCK_ACCESS_FS_TRUNCATE >>>> #define LANDLOCK_MASK_ACCESS_FS ((LANDLOCK_LAST_ACCESS_FS << 1) - 1) >>>> #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) >>>> +#define LANDLOCK_SHIFT_ACCESS_FS 0 >>>> >>>> /* clang-format on */ >>>> >>>> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c >>>> index 996484f98bfd..1f3188b4e313 100644 >>>> --- a/security/landlock/ruleset.c >>>> +++ b/security/landlock/ruleset.c >>>> @@ -29,7 +29,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >>>> struct landlock_ruleset *new_ruleset; >>>> >>>> new_ruleset = >>>> - kzalloc(struct_size(new_ruleset, fs_access_masks, num_layers), >>>> + kzalloc(struct_size(new_ruleset, access_masks, num_layers), >>>> GFP_KERNEL_ACCOUNT); >>>> if (!new_ruleset) >>>> return ERR_PTR(-ENOMEM); >>>> @@ -40,7 +40,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >>>> /* >>>> * hierarchy = NULL >>>> * num_rules = 0 >>>> - * fs_access_masks[] = 0 >>>> + * access_masks[] = 0 >>>> */ >>>> return new_ruleset; >>>> } >>>> @@ -55,7 +55,7 @@ landlock_create_ruleset(const access_mask_t fs_access_mask) >>>> return ERR_PTR(-ENOMSG); >>>> new_ruleset = create_ruleset(1); >>>> if (!IS_ERR(new_ruleset)) >>>> - new_ruleset->fs_access_masks[0] = fs_access_mask; >>>> + landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); >>>> return new_ruleset; >>>> } >>>> >>>> @@ -117,11 +117,12 @@ static void build_check_ruleset(void) >>>> .num_rules = ~0, >>>> .num_layers = ~0, >>>> }; >>>> - typeof(ruleset.fs_access_masks[0]) fs_access_mask = ~0; >>>> + typeof(ruleset.access_masks[0]) access_masks = ~0; >>>> >>>> BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); >>>> BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); >>>> - BUILD_BUG_ON(fs_access_mask < LANDLOCK_MASK_ACCESS_FS); >>>> + BUILD_BUG_ON(access_masks < >>>> + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); >>>> } >>>> >>>> /** >>>> @@ -281,7 +282,7 @@ static int merge_ruleset(struct landlock_ruleset *const dst, >>>> err = -EINVAL; >>>> goto out_unlock; >>>> } >>>> - dst->fs_access_masks[dst->num_layers - 1] = src->fs_access_masks[0]; >>>> + dst->access_masks[dst->num_layers - 1] = src->access_masks[0]; >>>> >>>> /* Merges the @src tree. */ >>>> rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, &src->root, >>>> @@ -340,8 +341,8 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, >>>> goto out_unlock; >>>> } >>>> /* Copies the parent layer stack and leaves a space for the new layer. */ >>>> - memcpy(child->fs_access_masks, parent->fs_access_masks, >>>> - flex_array_size(parent, fs_access_masks, parent->num_layers)); >>>> + memcpy(child->access_masks, parent->access_masks, >>>> + flex_array_size(parent, access_masks, parent->num_layers)); >>>> >>>> if (WARN_ON_ONCE(!parent->hierarchy)) { >>>> err = -EINVAL; >>>> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h >>>> index d43231b783e4..f2ad932d396c 100644 >>>> --- a/security/landlock/ruleset.h >>>> +++ b/security/landlock/ruleset.h >>>> @@ -25,6 +25,11 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); >>>> /* Makes sure for_each_set_bit() and for_each_clear_bit() calls are OK. */ >>>> static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); >>>> >>>> +/* Ruleset access masks. */ >>>> +typedef u16 access_masks_t; >>>> +/* Makes sure all ruleset access rights can be stored. */ >>>> +static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); >>>> + >>>> typedef u16 layer_mask_t; >>>> /* Makes sure all layers can be checked. */ >>>> static_assert(BITS_PER_TYPE(layer_mask_t) >= LANDLOCK_MAX_NUM_LAYERS); >>>> @@ -110,7 +115,7 @@ struct landlock_ruleset { >>>> * section. This is only used by >>>> * landlock_put_ruleset_deferred() when @usage reaches zero. >>>> * The fields @lock, @usage, @num_rules, @num_layers and >>>> - * @fs_access_masks are then unused. >>>> + * @access_masks are then unused. >>>> */ >>>> struct work_struct work_free; >>>> struct { >>>> @@ -137,7 +142,7 @@ struct landlock_ruleset { >>>> */ >>>> u32 num_layers; >>>> /** >>>> - * @fs_access_masks: Contains the subset of filesystem >>>> + * @access_masks: Contains the subset of filesystem >>>> * actions that are restricted by a ruleset. A domain >>>> * saves all layers of merged rulesets in a stack >>>> * (FAM), starting from the first layer to the last >>>> @@ -148,13 +153,13 @@ struct landlock_ruleset { >>>> * layers are set once and never changed for the >>>> * lifetime of the ruleset. >>>> */ >>>> - access_mask_t fs_access_masks[]; >>>> + access_masks_t access_masks[]; >>>> }; >>>> }; >>>> }; >>>> >>>> struct landlock_ruleset * >>>> -landlock_create_ruleset(const access_mask_t fs_access_mask); >>>> +landlock_create_ruleset(const access_mask_t access_mask); >>>> >>>> void landlock_put_ruleset(struct landlock_ruleset *const ruleset); >>>> void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); >>>> @@ -177,4 +182,26 @@ static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) >>>> refcount_inc(&ruleset->usage); >>>> } >>>> >>>> +static inline void >>>> +landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, >>>> + const access_mask_t fs_access_mask, >>>> + const u16 layer_level) >>>> +{ >>>> + access_mask_t fs_mask = fs_access_mask & LANDLOCK_MASK_ACCESS_FS; >>>> + >>>> + /* Should already be checked in sys_landlock_create_ruleset(). */ >>>> + WARN_ON_ONCE(fs_access_mask != fs_mask); >>>> + // TODO: Add tests to check "|=" and not "=" >>> >>> This todo should be done and removed. No more todos must remain. >>> >> I delete it in 10/12 Patch when add network seltests. > > You can delete it in this patch then. I'm reviewing the tests. Ok. Thanks. > .