From patchwork Tue Jun 21 08:22:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Konstantin Meskhidze (A)" X-Patchwork-Id: 12888824 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 1C5F5C43334 for ; Tue, 21 Jun 2022 08:23:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229829AbiFUIX2 (ORCPT ); Tue, 21 Jun 2022 04:23:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229468AbiFUIXX (ORCPT ); Tue, 21 Jun 2022 04:23:23 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E204CA444; Tue, 21 Jun 2022 01:23:21 -0700 (PDT) Received: from fraeml715-chm.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4LRzvP0xZsz6H7Dt; Tue, 21 Jun 2022 16:19:29 +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; Tue, 21 Jun 2022 10:23:19 +0200 Received: from mscphis00759.huawei.com (10.123.66.134) 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; Tue, 21 Jun 2022 09:23:19 +0100 From: Konstantin Meskhidze To: CC: , , , , , Subject: [PATCH v6 01/17] landlock: renames access mask Date: Tue, 21 Jun 2022 16:22:57 +0800 Message-ID: <20220621082313.3330667-2-konstantin.meskhidze@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220621082313.3330667-1-konstantin.meskhidze@huawei.com> References: <20220621082313.3330667-1-konstantin.meskhidze@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.123.66.134] X-ClientProxiedBy: mscpeml500001.china.huawei.com (7.188.26.142) To lhreml745-chm.china.huawei.com (10.201.108.195) X-CFilter-Loop: Reflected Precedence: bulk List-ID: To support network type rules, this modification extends and renames ruleset's access masks. This patch adds filesystem helper functions to set and get filesystem mask. Also the modification adds a helper structure landlock_access_mask to support managing multiple access mask. Signed-off-by: Konstantin Meskhidze --- 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 | 7 ++++--- security/landlock/ruleset.c | 18 +++++++++--------- security/landlock/ruleset.h | 25 ++++++++++++++++++++----- security/landlock/syscalls.c | 7 ++++--- 4 files changed, 37 insertions(+), 20 deletions(-) -- 2.25.1 diff --git a/security/landlock/fs.c b/security/landlock/fs.c index ec5a6247cd3e..e6da08ed99d1 100644 --- a/security/landlock/fs.c +++ b/security/landlock/fs.c @@ -167,7 +167,8 @@ 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_rights |= LANDLOCK_MASK_ACCESS_FS & + ~landlock_get_fs_access_mask(ruleset, 0); object = get_inode_object(d_backing_inode(path->dentry)); if (IS_ERR(object)) return PTR_ERR(object); @@ -286,7 +287,7 @@ get_handled_accesses(const struct landlock_ruleset *const domain) for (layer_level = 0; layer_level < domain->num_layers; layer_level++) { - if (domain->fs_access_masks[layer_level] & + if (landlock_get_fs_access_mask(domain, layer_level) & BIT_ULL(access_bit)) { access_dom |= BIT_ULL(access_bit); break; @@ -316,7 +317,7 @@ init_layer_masks(const struct landlock_ruleset *const domain, for_each_set_bit(access_bit, &access_req, ARRAY_SIZE(*layer_masks)) { - if (domain->fs_access_masks[layer_level] & + if (landlock_get_fs_access_mask(domain, layer_level) & BIT_ULL(access_bit)) { (*layer_masks)[access_bit] |= BIT_ULL(layer_level); diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c index 996484f98bfd..a3fd58d01f09 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); @@ -40,22 +40,22 @@ 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; } struct landlock_ruleset * -landlock_create_ruleset(const access_mask_t fs_access_mask) +landlock_create_ruleset(const access_mask_t access_mask) { struct landlock_ruleset *new_ruleset; /* Informs about useless ruleset. */ - if (!fs_access_mask) + if (!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_set_fs_access_mask(new_ruleset, access_mask, 0); return new_ruleset; } @@ -117,7 +117,7 @@ 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]) fs_access_mask = ~0; BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); @@ -281,7 +281,7 @@ 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 +340,8 @@ 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..bd7ab39859bf 100644 --- a/security/landlock/ruleset.h +++ b/security/landlock/ruleset.h @@ -19,7 +19,7 @@ #include "limits.h" #include "object.h" -typedef u16 access_mask_t; +typedef u32 access_mask_t; /* Makes sure all filesystem access rights can be stored. */ 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. */ @@ -110,7 +110,7 @@ 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 +137,7 @@ 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 +148,13 @@ struct landlock_ruleset { * layers are set once and never changed for the * lifetime of the ruleset. */ - access_mask_t fs_access_masks[]; + access_mask_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 +177,19 @@ static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) refcount_inc(&ruleset->usage); } +/* A helper function to set a filesystem mask. */ +static inline void +landlock_set_fs_access_mask(struct landlock_ruleset *ruleset, + const access_mask_t access_maskset, u16 mask_level) +{ + ruleset->access_masks[mask_level] = access_maskset; +} + +/* A helper function to get a filesystem mask. */ +static inline u32 +landlock_get_fs_access_mask(const struct landlock_ruleset *ruleset, + u16 mask_level) +{ + return ruleset->access_masks[mask_level]; +} #endif /* _SECURITY_LANDLOCK_RULESET_H */ diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c index 735a0865ea11..5836736ce9d7 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; }