From patchwork Mon May 16 15:20:30 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: 12850954 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 B704FC43217 for ; Mon, 16 May 2022 15:21:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245268AbiEPPVg (ORCPT ); Mon, 16 May 2022 11:21:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245232AbiEPPVG (ORCPT ); Mon, 16 May 2022 11:21:06 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C4F4D3BF94; Mon, 16 May 2022 08:20:59 -0700 (PDT) Received: from fraeml704-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4L22t44nJjz67Zm5; Mon, 16 May 2022 23:17:16 +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 15.1.2375.24; Mon, 16 May 2022 17:20:56 +0200 From: Konstantin Meskhidze To: CC: , , , , , Subject: [PATCH v5 07/15] landlock: add support network rules Date: Mon, 16 May 2022 23:20:30 +0800 Message-ID: <20220516152038.39594-8-konstantin.meskhidze@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220516152038.39594-1-konstantin.meskhidze@huawei.com> References: <20220516152038.39594-1-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 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_mask and get_mask for network. * Add rb_root root_net_port. Changes since v4: * Refactoring landlock_create_ruleset() - splits ruleset and masks checks. * Refactoring landlock_create_ruleset() and landlock mask setters/getters to support two rule types. * Refactoring landlock_add_rule syscall add_rule_path_beneath function by factoring out get_ruleset_from_fd() and landlock_put_ruleset(). --- security/landlock/limits.h | 8 +++- security/landlock/ruleset.c | 82 +++++++++++++++++++++++++++++++----- security/landlock/ruleset.h | 34 +++++++++++++-- security/landlock/syscalls.c | 45 +++++++++++--------- 4 files changed, 132 insertions(+), 37 deletions(-) -- 2.25.1 diff --git a/security/landlock/limits.h b/security/landlock/limits.h index b54184ab9439..23694bf05cb7 100644 --- a/security/landlock/limits.h +++ b/security/landlock/limits.h @@ -22,6 +22,12 @@ #define LANDLOCK_MASK_ACCESS_FS ((LANDLOCK_LAST_ACCESS_FS << 1) - 1) #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) -/* clang-format on */ +#define LANDLOCK_LAST_ACCESS_NET LANDLOCK_ACCESS_NET_CONNECT_TCP +#define LANDLOCK_MASK_ACCESS_NET ((LANDLOCK_LAST_ACCESS_NET << 1) - 1) +#define LANDLOCK_NUM_ACCESS_NET __const_hweight64(LANDLOCK_MASK_ACCESS_NET) +#define LANDLOCK_MASK_SHIFT_NET 16 + +#define LANDLOCK_RULE_TYPE_NUM LANDLOCK_RULE_NET_SERVICE +/* clang-format on */ #endif /* _SECURITY_LANDLOCK_LIMITS_H */ diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c index c4ed783d655b..ea9ecb3f471a 100644 --- a/security/landlock/ruleset.c +++ b/security/landlock/ruleset.c @@ -36,6 +36,7 @@ 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 @@ -46,17 +47,21 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) } struct landlock_ruleset *landlock_create_ruleset( - const access_mask_t access_mask) + const access_mask_t access_mask_fs, + const access_mask_t access_mask_net) { struct landlock_ruleset *new_ruleset; /* Informs about useless ruleset. */ - if (!access_mask) + if (!access_mask_fs && !access_mask_net) return ERR_PTR(-ENOMSG); new_ruleset = create_ruleset(1); - if (!IS_ERR(new_ruleset)) - landlock_set_fs_access_mask(new_ruleset, access_mask, 0); - + if (IS_ERR(new_ruleset)) + return new_ruleset; + if (access_mask_fs) + landlock_set_fs_access_mask(new_ruleset, access_mask_fs, 0); + if (access_mask_net) + landlock_set_net_access_mask(new_ruleset, access_mask_net, 0); return new_ruleset; } @@ -94,9 +99,11 @@ static struct landlock_rule *create_rule( return ERR_PTR(-ENOMEM); RB_CLEAR_NODE(&new_rule->node); - if (object_ptr) { + if (object_ptr && !object_data) { landlock_get_object(object_ptr); new_rule->object.ptr = object_ptr; + } else if (object_data && !object_ptr) { + new_rule->object.data = object_data; } else if (object_ptr && object_data) { WARN_ON_ONCE(1); return ERR_PTR(-EINVAL); @@ -132,10 +139,12 @@ 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); } /** @@ -183,6 +192,11 @@ static int insert_rule(struct landlock_ruleset *const ruleset, object_data = (uintptr_t)object_ptr; root = &ruleset->root_inode; break; + case LANDLOCK_RULE_NET_SERVICE: + if (WARN_ON_ONCE(object_ptr)) + return -EINVAL; + root = &ruleset->root_net_port; + break; default: WARN_ON_ONCE(1); return -EINVAL; @@ -237,6 +251,16 @@ static int insert_rule(struct landlock_ruleset *const ruleset, &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]); + 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; } @@ -254,6 +278,15 @@ static int insert_rule(struct landlock_ruleset *const ruleset, rb_link_node(&new_rule->node, parent_node, walker_node); rb_insert_color(&new_rule->node, &ruleset->root_inode); break; + case LANDLOCK_RULE_NET_SERVICE: + new_rule = create_rule(NULL, object_data, layers, + num_layers, NULL); + 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; } @@ -315,6 +348,9 @@ 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; } @@ -341,6 +377,11 @@ static int tree_merge(struct landlock_ruleset *const src, rule_type, &layers, ARRAY_SIZE(layers)); break; + case LANDLOCK_RULE_NET_SERVICE: + err = insert_rule(dst, NULL, walker_rule->object.data, + rule_type, &layers, + ARRAY_SIZE(layers)); + break; } if (err) return err; @@ -376,6 +417,10 @@ 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); @@ -395,6 +440,9 @@ 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; } @@ -407,6 +455,12 @@ static int tree_copy(struct landlock_ruleset *const parent, rule_type, &walker_rule->layers, walker_rule->num_layers); break; + case LANDLOCK_RULE_NET_SERVICE: + err = insert_rule(child, NULL, + walker_rule->object.data, rule_type, + &walker_rule->layers, + walker_rule->num_layers); + break; } if (err) return err; @@ -429,6 +483,10 @@ 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; @@ -463,9 +521,11 @@ static void free_ruleset(struct landlock_ruleset *const ruleset) might_sleep(); rbtree_postorder_for_each_entry_safe(freeme, next, - &ruleset->root_inode, - node) + &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); } @@ -560,13 +620,13 @@ const struct landlock_rule *landlock_find_rule( { const struct rb_node *node; - if (!object_data) - return NULL; - switch (rule_type) { 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: WARN_ON_ONCE(1); return NULL; diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h index f3cd890d0348..916b30b31c06 100644 --- a/security/landlock/ruleset.h +++ b/security/landlock/ruleset.h @@ -102,6 +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. @@ -157,7 +163,8 @@ struct landlock_ruleset { }; struct landlock_ruleset *landlock_create_ruleset( - const access_mask_t access_mask); + const access_mask_t access_mask_fs, + const access_mask_t access_mask_net); void landlock_put_ruleset(struct landlock_ruleset *const ruleset); void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); @@ -183,11 +190,12 @@ static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) } /* 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, +static inline void landlock_set_fs_access_mask( + struct landlock_ruleset *ruleset, + const access_mask_t access_mask_fs, u16 mask_level) { - ruleset->access_masks[mask_level] = access_maskset; + ruleset->access_masks[mask_level] = access_mask_fs; } /* A helper function to get a filesystem mask */ @@ -198,6 +206,24 @@ static inline u32 landlock_get_fs_access_mask( return (ruleset->access_masks[mask_level] & LANDLOCK_MASK_ACCESS_FS); } +/* A helper function to set a network mask */ +static inline void landlock_set_net_access_mask( + struct landlock_ruleset *ruleset, + const access_mask_t access_mask_net, + u16 mask_level) +{ + ruleset->access_masks[mask_level] |= (access_mask_net << + LANDLOCK_MASK_SHIFT_NET); +} + +/* A helper function to get a network mask */ +static inline u32 landlock_get_net_access_mask( + const struct landlock_ruleset *ruleset, + u16 mask_level) +{ + return (ruleset->access_masks[mask_level] >> LANDLOCK_MASK_SHIFT_NET); +} + access_mask_t get_handled_accesses( const struct landlock_ruleset *const domain, u16 rule_type, u16 num_access); diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c index 31f9facec123..812541f4e155 100644 --- a/security/landlock/syscalls.c +++ b/security/landlock/syscalls.c @@ -189,8 +189,14 @@ SYSCALL_DEFINE3(landlock_create_ruleset, LANDLOCK_MASK_ACCESS_FS) return -EINVAL; + /* Checks network content (and 32-bits cast). */ + if ((ruleset_attr.handled_access_net | LANDLOCK_MASK_ACCESS_NET) != + LANDLOCK_MASK_ACCESS_NET) + return -EINVAL; + /* Checks arguments and transforms to kernel struct. */ - ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs); + ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs, + ruleset_attr.handled_access_net); if (IS_ERR(ruleset)) return PTR_ERR(ruleset); @@ -275,21 +281,17 @@ static int get_path_from_fd(const s32 fd, struct path *const path) return err; } -static int add_rule_path_beneath(const int ruleset_fd, const void *const rule_attr) +static int add_rule_path_beneath(struct landlock_ruleset *const ruleset, + const void *const rule_attr) { struct landlock_path_beneath_attr path_beneath_attr; struct path path; - struct landlock_ruleset *ruleset; int res, err; - - /* Gets and checks the ruleset. */ - ruleset = get_ruleset_from_fd(ruleset_fd, FMODE_CAN_WRITE); - if (IS_ERR(ruleset)) - return PTR_ERR(ruleset); + u32 mask; /* Copies raw user space buffer, only one type for now. */ res = copy_from_user(&path_beneath_attr, rule_attr, - sizeof(path_beneath_attr)); + sizeof(path_beneath_attr)); if (res) return -EFAULT; @@ -298,32 +300,26 @@ static int add_rule_path_beneath(const int ruleset_fd, const void *const rule_at * are ignored in path walks. */ if (!path_beneath_attr.allowed_access) { - err = -ENOMSG; - goto out_put_ruleset; + return -ENOMSG; } /* * Checks that allowed_access matches the @ruleset constraints * (ruleset->access_masks[0] is automatically upgraded to 64-bits). */ - 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; - } + mask = landlock_get_fs_access_mask(ruleset, 0); + if ((path_beneath_attr.allowed_access | mask) != mask) + return -EINVAL; /* Gets and checks the new rule. */ err = get_path_from_fd(path_beneath_attr.parent_fd, &path); if (err) - goto out_put_ruleset; + return err; /* Imports the new rule. */ err = landlock_append_fs_rule(ruleset, &path, path_beneath_attr.allowed_access); path_put(&path); -out_put_ruleset: - landlock_put_ruleset(ruleset); return err; } @@ -360,6 +356,7 @@ SYSCALL_DEFINE4(landlock_add_rule, const int, ruleset_fd, const enum landlock_rule_type, rule_type, const void __user *const, rule_attr, const __u32, flags) { + struct landlock_ruleset *ruleset; int err; if (!landlock_initialized) @@ -369,14 +366,20 @@ SYSCALL_DEFINE4(landlock_add_rule, if (flags) return -EINVAL; + /* Gets and checks the ruleset. */ + ruleset = get_ruleset_from_fd(ruleset_fd, FMODE_CAN_WRITE); + if (IS_ERR(ruleset)) + return PTR_ERR(ruleset); + switch (rule_type) { case LANDLOCK_RULE_PATH_BENEATH: - err = add_rule_path_beneath(ruleset_fd, rule_attr); + err = add_rule_path_beneath(ruleset, rule_attr); break; default: err = -EINVAL; break; } + landlock_put_ruleset(ruleset); return err; }