From patchwork Wed Mar 9 13:44:48 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: 12775106 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 64E7CC43217 for ; Wed, 9 Mar 2022 13:45:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232756AbiCINqT (ORCPT ); Wed, 9 Mar 2022 08:46:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232717AbiCINqS (ORCPT ); Wed, 9 Mar 2022 08:46:18 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C61417B8A8; Wed, 9 Mar 2022 05:45:16 -0800 (PST) Received: from fraeml704-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4KDD2k2p0gz67bVT; Wed, 9 Mar 2022 21:44:46 +0800 (CST) Received: from mscphispre00059.huawei.com (10.123.71.64) by fraeml704-chm.china.huawei.com (10.206.15.53) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.21; Wed, 9 Mar 2022 14:45:13 +0100 From: Konstantin Meskhidze To: CC: , , , , , , Subject: [RFC PATCH v4 04/15] landlock: merge and inherit function refactoring Date: Wed, 9 Mar 2022 21:44:48 +0800 Message-ID: <20220309134459.6448-5-konstantin.meskhidze@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220309134459.6448-1-konstantin.meskhidze@huawei.com> References: <20220309134459.6448-1-konstantin.meskhidze@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.123.71.64] X-ClientProxiedBy: mscpeml500001.china.huawei.com (7.188.26.142) To fraeml704-chm.china.huawei.com (10.206.15.53) X-CFilter-Loop: Reflected Precedence: bulk List-ID: Merge_ruleset() and inherit_ruleset() functions were refactored to support new rule types. This patch adds tree_merge() and tree_copy() helpers. Each has rule_type argument to choose a particular rb_tree structure in a ruleset. Signed-off-by: Konstantin Meskhidze --- Changes since v3: * Split commit. * Refactoring functions: -insert_rule. -merge_ruleset. -tree_merge. -inherit_ruleset. -tree_copy. -free_rule. --- security/landlock/ruleset.c | 141 +++++++++++++++++++++++++----------- 1 file changed, 97 insertions(+), 44 deletions(-) -- 2.25.1 diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c index 971685c48641..f2baa1c96b16 100644 --- a/security/landlock/ruleset.c +++ b/security/landlock/ruleset.c @@ -125,12 +125,16 @@ static struct landlock_rule *create_rule( return new_rule; } -static void free_rule(struct landlock_rule *const rule) +static void free_rule(struct landlock_rule *const rule, const u16 rule_type) { might_sleep(); if (!rule) return; - landlock_put_object(rule->object.ptr); + switch (rule_type) { + case LANDLOCK_RULE_PATH_BENEATH: + landlock_put_object(rule->object.ptr); + break; + } kfree(rule); } @@ -233,12 +237,12 @@ static int insert_rule(struct landlock_ruleset *const ruleset, case LANDLOCK_RULE_PATH_BENEATH: new_rule = create_rule(object_ptr, 0, &this->layers, this->num_layers, &(*layers)[0], rule_type); + if (IS_ERR(new_rule)) + return PTR_ERR(new_rule); + rb_replace_node(&this->node, &new_rule->node, &ruleset->root_inode); + free_rule(this, rule_type); break; } - if (IS_ERR(new_rule)) - return PTR_ERR(new_rule); - rb_replace_node(&this->node, &new_rule->node, &ruleset->root_inode); - free_rule(this); return 0; } @@ -249,13 +253,13 @@ static int insert_rule(struct landlock_ruleset *const ruleset, switch (rule_type) { case LANDLOCK_RULE_PATH_BENEATH: new_rule = create_rule(object_ptr, 0, layers, num_layers, NULL, rule_type); + if (IS_ERR(new_rule)) + return PTR_ERR(new_rule); + rb_link_node(&new_rule->node, parent_node, walker_node); + rb_insert_color(&new_rule->node, &ruleset->root_inode); + ruleset->num_rules++; break; } - if (IS_ERR(new_rule)) - return PTR_ERR(new_rule); - rb_link_node(&new_rule->node, parent_node, walker_node); - rb_insert_color(&new_rule->node, &ruleset->root_inode); - ruleset->num_rules++; return 0; } @@ -303,10 +307,53 @@ static void put_hierarchy(struct landlock_hierarchy *hierarchy) } } +static int tree_merge(struct landlock_ruleset *const src, + struct landlock_ruleset *const dst, u16 rule_type) +{ + struct landlock_rule *walker_rule, *next_rule; + struct rb_root *src_root; + int err = 0; + + /* Choose rb_tree structure depending on a rule type */ + switch (rule_type) { + case LANDLOCK_RULE_PATH_BENEATH: + src_root = &src->root_inode; + break; + default: + return -EINVAL; + } + /* Merges the @src tree. */ + rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, + src_root, node) { + struct landlock_layer layers[] = {{ + .level = dst->num_layers, + }}; + + if (WARN_ON_ONCE(walker_rule->num_layers != 1)) { + err = -EINVAL; + return err; + } + if (WARN_ON_ONCE(walker_rule->layers[0].level != 0)) { + err = -EINVAL; + return err; + } + layers[0].access = walker_rule->layers[0].access; + + switch (rule_type) { + case LANDLOCK_RULE_PATH_BENEATH: + err = insert_rule(dst, walker_rule->object.ptr, 0, &layers, + ARRAY_SIZE(layers), rule_type); + break; + } + if (err) + return err; + } + return err; +} + static int merge_ruleset(struct landlock_ruleset *const dst, struct landlock_ruleset *const src) { - struct landlock_rule *walker_rule, *next_rule; int err = 0; might_sleep(); @@ -328,27 +375,10 @@ static int merge_ruleset(struct landlock_ruleset *const dst, } 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_inode, node) { - struct landlock_layer layers[] = {{ - .level = dst->num_layers, - }}; - - if (WARN_ON_ONCE(walker_rule->num_layers != 1)) { - err = -EINVAL; - goto out_unlock; - } - if (WARN_ON_ONCE(walker_rule->layers[0].level != 0)) { - err = -EINVAL; - goto out_unlock; - } - layers[0].access = walker_rule->layers[0].access; - err = insert_rule(dst, walker_rule->object.ptr, 0, &layers, - ARRAY_SIZE(layers), LANDLOCK_RULE_PATH_BENEATH); - if (err) - goto out_unlock; - } + /* Merges the @src inode tree. */ + err = tree_merge(src, dst, LANDLOCK_RULE_PATH_BENEATH); + if (err) + goto out_unlock; out_unlock: mutex_unlock(&src->lock); @@ -356,12 +386,40 @@ static int merge_ruleset(struct landlock_ruleset *const dst, return err; } +static int tree_copy(struct landlock_ruleset *const parent, + struct landlock_ruleset *const child, u16 rule_type) +{ + struct landlock_rule *walker_rule, *next_rule; + struct rb_root *parent_root; + int err = 0; + /* Choose rb_tree structure depending on a rule type */ + switch (rule_type) { + case LANDLOCK_RULE_PATH_BENEATH: + parent_root = &parent->root_inode; + break; + default: + return -EINVAL; + } + /* Copies the @parent inode tree. */ + rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, + parent_root, node) { + switch (rule_type) { + case LANDLOCK_RULE_PATH_BENEATH: + err = insert_rule(child, walker_rule->object.ptr, 0, + &walker_rule->layers, walker_rule->num_layers, + rule_type); + break; + } + if (err) + return err; + } + return err; +} static int inherit_ruleset(struct landlock_ruleset *const parent, struct landlock_ruleset *const child) { - struct landlock_rule *walker_rule, *next_rule; int err = 0; might_sleep(); @@ -372,15 +430,10 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, mutex_lock(&child->lock); mutex_lock_nested(&parent->lock, SINGLE_DEPTH_NESTING); - /* Copies the @parent tree. */ - rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, - &parent->root_inode, node) { - err = insert_rule(child, walker_rule->object.ptr, 0, - &walker_rule->layers, walker_rule->num_layers, - LANDLOCK_RULE_PATH_BENEATH); - if (err) - goto out_unlock; - } + /* Copies the @parent inode tree. */ + err = tree_copy(parent, child, LANDLOCK_RULE_PATH_BENEATH); + if (err) + goto out_unlock; if (WARN_ON_ONCE(child->num_layers <= parent->num_layers)) { err = -EINVAL; @@ -410,7 +463,7 @@ static void free_ruleset(struct landlock_ruleset *const ruleset) might_sleep(); rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root_inode, node) - free_rule(freeme); + free_rule(freeme, LANDLOCK_RULE_PATH_BENEATH); put_hierarchy(ruleset->hierarchy); kfree(ruleset); }