From patchwork Wed Mar 9 13:44:52 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: 12775093 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 B5C90C433FE for ; Wed, 9 Mar 2022 13:45:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232871AbiCINqd (ORCPT ); Wed, 9 Mar 2022 08:46:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232932AbiCINqa (ORCPT ); Wed, 9 Mar 2022 08:46:30 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A07CB17B8A5; Wed, 9 Mar 2022 05:45:21 -0800 (PST) Received: from fraeml704-chm.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4KDD1m5Dr0z67Nc8; Wed, 9 Mar 2022 21:43:56 +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 14:45:19 +0100 From: Konstantin Meskhidze To: CC: , , , , , , Subject: [RFC PATCH v4 08/15] landlock: add support network rules Date: Wed, 9 Mar 2022 21:44:52 +0800 Message-ID: <20220309134459.6448-9-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: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-State: RFC This modification adds network rules support in internal landlock functions (presented in ruleset.c) and landlock_create_ruleset syscall. Signed-off-by: Konstantin Meskhidze --- Changes since v3: * Split commit. * Add network rule support for internal landlock functions. * Add set_masks and get_masks for network. * Add rb_root root_net_port. --- security/landlock/fs.c | 2 +- security/landlock/limits.h | 6 +++ security/landlock/ruleset.c | 88 +++++++++++++++++++++++++++++++++--- security/landlock/ruleset.h | 14 +++++- security/landlock/syscalls.c | 10 +++- 5 files changed, 109 insertions(+), 11 deletions(-) -- 2.25.1 diff --git a/security/landlock/fs.c b/security/landlock/fs.c index 75ebdce5cd16..5cd339061cdb 100644 --- a/security/landlock/fs.c +++ b/security/landlock/fs.c @@ -231,7 +231,7 @@ static int check_access_path(const struct landlock_ruleset *const domain, inode = d_backing_inode(walker_path.dentry); object_ptr = landlock_inode(inode)->object; - layer_mask = landlock_unmask_layers(domain, object_ptr, + layer_mask = landlock_unmask_layers(domain, object_ptr, 0, access_request, layer_mask, LANDLOCK_RULE_PATH_BENEATH); if (layer_mask == 0) { diff --git a/security/landlock/limits.h b/security/landlock/limits.h index 2a0a1095ee27..fdbef85e4de0 100644 --- a/security/landlock/limits.h +++ b/security/landlock/limits.h @@ -18,4 +18,10 @@ #define LANDLOCK_LAST_ACCESS_FS LANDLOCK_ACCESS_FS_MAKE_SYM #define LANDLOCK_MASK_ACCESS_FS ((LANDLOCK_LAST_ACCESS_FS << 1) - 1) +#define LANDLOCK_LAST_ACCESS_NET LANDLOCK_ACCESS_NET_CONNECT_TCP +#define LANDLOCK_MASK_ACCESS_NET ((LANDLOCK_LAST_ACCESS_NET << 1) - 1) +#define LANDLOCK_MASK_SHIFT_NET 16 + +#define LANDLOCK_RULE_TYPE_NUM LANDLOCK_RULE_NET_SERVICE + #endif /* _SECURITY_LANDLOCK_LIMITS_H */ diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c index 7179b10f3538..1cecca59a942 100644 --- a/security/landlock/ruleset.c +++ b/security/landlock/ruleset.c @@ -35,6 +35,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) refcount_set(&new_ruleset->usage, 1); mutex_init(&new_ruleset->lock); new_ruleset->root_inode = RB_ROOT; + new_ruleset->root_net_port = RB_ROOT; new_ruleset->num_layers = num_layers; /* * hierarchy = NULL @@ -58,16 +59,32 @@ u32 landlock_get_fs_access_mask(const struct landlock_ruleset *ruleset, u16 mask return ruleset->access_masks[mask_level]; } +/* A helper function to set a network mask */ +void landlock_set_net_access_mask(struct landlock_ruleset *ruleset, + const struct landlock_access_mask *access_mask_set, + u16 mask_level) +{ + ruleset->access_masks[mask_level] |= (access_mask_set->net << LANDLOCK_MASK_SHIFT_NET); +} + +/* A helper function to get a network mask */ +u32 landlock_get_net_access_mask(const struct landlock_ruleset *ruleset, u16 mask_level) +{ + return (ruleset->access_masks[mask_level] >> LANDLOCK_MASK_SHIFT_NET); +} + struct landlock_ruleset *landlock_create_ruleset(const struct landlock_access_mask *access_mask_set) { struct landlock_ruleset *new_ruleset; /* Informs about useless ruleset. */ - if (!access_mask_set->fs) + if (!access_mask_set->fs && !access_mask_set->net) return ERR_PTR(-ENOMSG); new_ruleset = create_ruleset(1); - if (!IS_ERR(new_ruleset)) + if (!IS_ERR(new_ruleset) && access_mask_set->fs) landlock_set_fs_access_mask(new_ruleset, access_mask_set, 0); + if (!IS_ERR(new_ruleset) && access_mask_set->net) + landlock_set_net_access_mask(new_ruleset, access_mask_set, 0); return new_ruleset; } @@ -111,6 +128,9 @@ static struct landlock_rule *create_rule( landlock_get_object(object_ptr); new_rule->object.ptr = object_ptr; break; + case LANDLOCK_RULE_NET_SERVICE: + new_rule->object.data = object_data; + break; default: return ERR_PTR(-EINVAL); } @@ -145,10 +165,12 @@ static void build_check_ruleset(void) .num_layers = ~0, }; typeof(ruleset.access_masks[0]) fs_access_mask = ~0; + typeof(ruleset.access_masks[0]) net_access_mask = ~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(net_access_mask < LANDLOCK_MASK_ACCESS_NET); } /** @@ -191,6 +213,12 @@ static int insert_rule(struct landlock_ruleset *const ruleset, object = (uintptr_t)object_ptr; root = &ruleset->root_inode; break; + case LANDLOCK_RULE_NET_SERVICE: + if (WARN_ON_ONCE(!object_data || !layers)) + return -ENOENT; + object = object_data; + root = &ruleset->root_net_port; + break; default: return -EINVAL; } @@ -242,6 +270,14 @@ static int insert_rule(struct landlock_ruleset *const ruleset, rb_replace_node(&this->node, &new_rule->node, &ruleset->root_inode); free_rule(this, rule_type); break; + case LANDLOCK_RULE_NET_SERVICE: + new_rule = create_rule(NULL, object_data, &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_net_port); + free_rule(this, rule_type); + break; } return 0; } @@ -259,6 +295,14 @@ static int insert_rule(struct landlock_ruleset *const ruleset, rb_insert_color(&new_rule->node, &ruleset->root_inode); ruleset->num_rules++; break; + case LANDLOCK_RULE_NET_SERVICE: + new_rule = create_rule(NULL, object_data, 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_net_port); + ruleset->num_rules++; + break; } return 0; } @@ -319,6 +363,9 @@ static int tree_merge(struct landlock_ruleset *const src, case LANDLOCK_RULE_PATH_BENEATH: src_root = &src->root_inode; break; + case LANDLOCK_RULE_NET_SERVICE: + src_root = &src->root_net_port; + break; default: return -EINVAL; } @@ -338,11 +385,14 @@ static int tree_merge(struct landlock_ruleset *const src, 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); + ARRAY_SIZE(layers), rule_type); + break; + case LANDLOCK_RULE_NET_SERVICE: + err = insert_rule(dst, NULL, walker_rule->object.data, &layers, + ARRAY_SIZE(layers), rule_type); break; } if (err) @@ -379,6 +429,10 @@ static int merge_ruleset(struct landlock_ruleset *const dst, err = tree_merge(src, dst, LANDLOCK_RULE_PATH_BENEATH); if (err) goto out_unlock; + /* Merges the @src network tree. */ + err = tree_merge(src, dst, LANDLOCK_RULE_NET_SERVICE); + if (err) + goto out_unlock; out_unlock: mutex_unlock(&src->lock); @@ -398,6 +452,9 @@ static int tree_copy(struct landlock_ruleset *const parent, case LANDLOCK_RULE_PATH_BENEATH: parent_root = &parent->root_inode; break; + case LANDLOCK_RULE_NET_SERVICE: + parent_root = &parent->root_net_port; + break; default: return -EINVAL; } @@ -410,6 +467,11 @@ static int tree_copy(struct landlock_ruleset *const parent, &walker_rule->layers, walker_rule->num_layers, rule_type); break; + case LANDLOCK_RULE_NET_SERVICE: + err = insert_rule(child, NULL, walker_rule->object.data, + &walker_rule->layers, walker_rule->num_layers, + rule_type); + break; } if (err) return err; @@ -432,6 +494,10 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, /* Copies the @parent inode tree. */ err = tree_copy(parent, child, LANDLOCK_RULE_PATH_BENEATH); + if (err) + goto out_unlock; + /* Copies the @parent inode tree. */ + err = tree_copy(parent, child, LANDLOCK_RULE_NET_SERVICE); if (err) goto out_unlock; @@ -464,6 +530,9 @@ static void free_ruleset(struct landlock_ruleset *const ruleset) rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root_inode, node) free_rule(freeme, LANDLOCK_RULE_PATH_BENEATH); + rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root_net_port, + node) + free_rule(freeme, LANDLOCK_RULE_NET_SERVICE); put_hierarchy(ruleset->hierarchy); kfree(ruleset); } @@ -565,6 +634,9 @@ const struct landlock_rule *landlock_find_rule( case LANDLOCK_RULE_PATH_BENEATH: node = ruleset->root_inode.rb_node; break; + case LANDLOCK_RULE_NET_SERVICE: + node = ruleset->root_net_port.rb_node; + break; default: return ERR_PTR(-EINVAL); } @@ -586,8 +658,8 @@ const struct landlock_rule *landlock_find_rule( /* Access-control management */ u64 landlock_unmask_layers(const struct landlock_ruleset *const domain, const struct landlock_object *object_ptr, - const u32 access_request, u64 layer_mask, - const u16 rule_type) + const u16 port, const u32 access_request, + u64 layer_mask, const u16 rule_type) { const struct landlock_rule *rule; size_t i; @@ -600,6 +672,10 @@ u64 landlock_unmask_layers(const struct landlock_ruleset *const domain, LANDLOCK_RULE_PATH_BENEATH); rcu_read_unlock(); break; + case LANDLOCK_RULE_NET_SERVICE: + rule = landlock_find_rule(domain, (uintptr_t)port, + LANDLOCK_RULE_NET_SERVICE); + break; } if (!rule) diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h index 0a7d4b1f51fd..abf3e09a65cd 100644 --- a/security/landlock/ruleset.h +++ b/security/landlock/ruleset.h @@ -24,6 +24,10 @@ struct landlock_access_mask { * @fs: Filesystem access mask. */ u16 fs; + /** + * @net: Network access mask. + */ + u16 net; }; /** @@ -98,6 +102,12 @@ struct landlock_ruleset { * tree is immutable until @usage reaches zero. */ struct rb_root root_inode; + /** + * @root_net_port: Root of a red-black tree containing object nodes + * for network port. Once a ruleset is tied to a process (i.e. as a domain), + * this tree is immutable until @usage reaches zero. + */ + struct rb_root root_net_port; /** * @hierarchy: Enables hierarchy identification even when a parent * domain vanishes. This is needed for the ptrace protection. @@ -185,7 +195,7 @@ u32 landlock_get_fs_access_mask(const struct landlock_ruleset *ruleset, u16 mask u64 landlock_unmask_layers(const struct landlock_ruleset *const domain, const struct landlock_object *object_ptr, - const u32 access_request, u64 layer_mask, - const u16 rule_type); + const u16 port, const u32 access_request, + u64 layer_mask, const u16 rule_type); #endif /* _SECURITY_LANDLOCK_RULESET_H */ diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c index fcbce83d64ef..b91455a19356 100644 --- a/security/landlock/syscalls.c +++ b/security/landlock/syscalls.c @@ -160,7 +160,7 @@ SYSCALL_DEFINE3(landlock_create_ruleset, { struct landlock_ruleset_attr ruleset_attr; struct landlock_ruleset *ruleset; - struct landlock_access_mask access_mask_set = {.fs = 0}; + struct landlock_access_mask access_mask_set = {.fs = 0, .net = 0}; int err, ruleset_fd; /* Build-time checks. */ @@ -187,8 +187,14 @@ SYSCALL_DEFINE3(landlock_create_ruleset, if ((ruleset_attr.handled_access_fs | LANDLOCK_MASK_ACCESS_FS) != LANDLOCK_MASK_ACCESS_FS) return -EINVAL; - access_mask_set.fs = ruleset_attr.handled_access_fs; + /* Checks network content (and 32-bits cast). */ + if ((ruleset_attr.handled_access_net | LANDLOCK_MASK_ACCESS_NET) != + LANDLOCK_MASK_ACCESS_NET) + return -EINVAL; + + access_mask_set.fs = ruleset_attr.handled_access_fs; + access_mask_set.net = ruleset_attr.handled_access_net; /* Checks arguments and transforms to kernel struct. */ ruleset = landlock_create_ruleset(&access_mask_set); if (IS_ERR(ruleset))