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 BFC6FC352A1 for ; Mon, 28 Nov 2022 02:54:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229509AbiK1CyA (ORCPT ); Sun, 27 Nov 2022 21:54:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54046 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229529AbiK1Cx5 (ORCPT ); Sun, 27 Nov 2022 21:53:57 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4CF5B115C; Sun, 27 Nov 2022 18:53:56 -0800 (PST) Received: from fraeml701-chm.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4NL95Z0ySSz67Mrg; Mon, 28 Nov 2022 10:53:38 +0800 (CST) Received: from lhrpeml500004.china.huawei.com (7.191.163.9) by fraeml701-chm.china.huawei.com (10.206.15.50) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2375.31; Mon, 28 Nov 2022 03:53:54 +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; Mon, 28 Nov 2022 02:53:53 +0000 Message-ID: <3f9fc69d-1604-d879-d341-8a831beabeea@huawei.com> Date: Mon, 28 Nov 2022 05:53:52 +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> From: "Konstantin Meskhidze (A)" In-Reply-To: <94ed4212-c093-9c5c-089f-e9e4097e5bd6@digikod.net> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.122.132.241] X-ClientProxiedBy: lhrpeml500006.china.huawei.com (7.191.161.198) To lhrpeml500004.china.huawei.com (7.191.163.9) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 11/17/2022 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. > >> + ruleset->access_masks[layer_level] |= >> + (fs_mask << LANDLOCK_SHIFT_ACCESS_FS); >> +} >> + >> +static inline access_mask_t >> +landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, >> + const u16 layer_level) >> +{ >> + return (ruleset->access_masks[layer_level] >> >> + LANDLOCK_SHIFT_ACCESS_FS) & >> + LANDLOCK_MASK_ACCESS_FS; >> +} >> #endif /* _SECURITY_LANDLOCK_RULESET_H */ >> diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c >> index 245cc650a4dc..71aca7f990bc 100644 >> --- a/security/landlock/syscalls.c >> +++ b/security/landlock/syscalls.c >> @@ -346,10 +346,11 @@ SYSCALL_DEFINE4(landlock_add_rule, const int, ruleset_fd, >> } >> /* >> * Checks that allowed_access matches the @ruleset constraints >> - * (ruleset->fs_access_masks[0] is automatically upgraded to 64-bits). >> + * (ruleset->access_masks[0] is automatically upgraded to 64-bits). >> */ >> - if ((path_beneath_attr.allowed_access | ruleset->fs_access_masks[0]) != >> - ruleset->fs_access_masks[0]) { >> + if ((path_beneath_attr.allowed_access | >> + landlock_get_fs_access_mask(ruleset, 0)) != >> + landlock_get_fs_access_mask(ruleset, 0)) { >> err = -EINVAL; >> goto out_put_ruleset; >> } >> -- >> 2.25.1 >> > > I'll send a patch to be applied after this one. > .