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 E28AEC4321E for ; Mon, 28 Nov 2022 20:23:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233506AbiK1UXG (ORCPT ); Mon, 28 Nov 2022 15:23:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233485AbiK1UXB (ORCPT ); Mon, 28 Nov 2022 15:23:01 -0500 Received: from smtp-8fac.mail.infomaniak.ch (smtp-8fac.mail.infomaniak.ch [IPv6:2001:1600:4:17::8fac]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C93AB17889 for ; Mon, 28 Nov 2022 12:22:59 -0800 (PST) Received: from smtp-2-0000.mail.infomaniak.ch (unknown [10.5.36.107]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4NLcNH3mYZzMq31x; Mon, 28 Nov 2022 21:22:55 +0100 (CET) Received: from ns3096276.ip-94-23-54.eu (unknown [23.97.221.149]) by smtp-2-0000.mail.infomaniak.ch (Postfix) with ESMTPA id 4NLcNG5nn5zMpr8S; Mon, 28 Nov 2022 21:22:54 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=digikod.net; s=20191114; t=1669666975; bh=ycBcDca4fx/vos/2FxtUX6s4HweUMUxNNjrwbPanxmw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=uAk08fYF5VW7jGRTdMF6Q78dOs/SzBLpUfxUE0+SU/KEt6I8OzgA79dcufGOU9SDh efZYPp9Xkei0VzjNKGnpmOQRaLgdQJPqXYR2C3g+j0ut0Y2UTGyHFVLQU169LggIBu pQvgTjp8Ny95WvDQWgRO9Q468CXUxN3fd8pY5LF4= Message-ID: <700956d7-9831-da1d-c397-d1fb45aaf5d7@digikod.net> Date: Mon, 28 Nov 2022 21:22:54 +0100 MIME-Version: 1.0 User-Agent: Subject: Re: [PATCH v8 01/12] landlock: Make ruleset's access masks more generic Content-Language: en-US To: "Konstantin Meskhidze (A)" Cc: willemdebruijn.kernel@gmail.com, gnoack3000@gmail.com, linux-security-module@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, artem.kuzin@huawei.com 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> From: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= In-Reply-To: <3f9fc69d-1604-d879-d341-8a831beabeea@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Infomaniak-Routing: alpha Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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.