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 44307C6FA82 for ; Mon, 12 Sep 2022 17:18:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230118AbiILRSX (ORCPT ); Mon, 12 Sep 2022 13:18:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230121AbiILRSU (ORCPT ); Mon, 12 Sep 2022 13:18:20 -0400 Received: from smtp-bc09.mail.infomaniak.ch (smtp-bc09.mail.infomaniak.ch [45.157.188.9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E33C63ED75 for ; Mon, 12 Sep 2022 10:18:17 -0700 (PDT) Received: from smtp-2-0001.mail.infomaniak.ch (unknown [10.5.36.108]) by smtp-2-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4MRCwm3XmZzMppNZ; Mon, 12 Sep 2022 19:18:16 +0200 (CEST) Received: from ns3096276.ip-94-23-54.eu (unknown [23.97.221.149]) by smtp-2-0001.mail.infomaniak.ch (Postfix) with ESMTPA id 4MRCwm02GDzMpq1Z; Mon, 12 Sep 2022 19:18:15 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=digikod.net; s=20191114; t=1663003096; bh=PM3uytveGpTRTp6GYYaV8/MPibYRWnOFb4ge4C09rWg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=cKaZPJkvJppVR2KLKVuu7iH3VJzwk4FSvXA5HWUWaJCo3s7nf2ScG+YsektjIvDIk MquKSl2wT3+ncv9odYySX0RVnKyp04ZJKZQQUyWLVO+V6YWJpULFcLirgdO0hVYgeI rtwSZM/ZapSMh6PbyG7+ZA96hljEHPRhQt7A9QrQ= Message-ID: <369537f3-78e1-2a4e-c010-d56e29c2f315@digikod.net> Date: Mon, 12 Sep 2022 19:18:15 +0200 MIME-Version: 1.0 User-Agent: Subject: Re: [PATCH v7 08/18] landlock: add network rules support 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, anton.sirazetdinov@huawei.com References: <20220829170401.834298-1-konstantin.meskhidze@huawei.com> <20220829170401.834298-9-konstantin.meskhidze@huawei.com> <9cf95acb-14a0-0900-c5af-c910de80e289@digikod.net> <1563a50e-e345-4abb-1c4d-45284102ca6b@huawei.com> From: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= In-Reply-To: <1563a50e-e345-4abb-1c4d-45284102ca6b@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On 10/09/2022 20:27, Konstantin Meskhidze (A) wrote: > > > 9/6/2022 11:08 AM, Mickaël Salaün пишет: >> >> On 29/08/2022 19:03, Konstantin Meskhidze wrote: >>> This commit adds network rules support in internal landlock functions >>> (presented in ruleset.c) and landlock_create_ruleset syscall. >>> >>> Signed-off-by: Konstantin Meskhidze >>> --- >>> >>> Changes since v6: >>> * Renames landlock_set_net_access_mask() to landlock_add_net_access_mask() >>> because it OR values. >>> * Makes landlock_add_net_access_mask() more resilient incorrect values. >>> * Refactors landlock_get_net_access_mask(). >>> * Renames LANDLOCK_MASK_SHIFT_NET to LANDLOCK_SHIFT_ACCESS_NET and use >>> LANDLOCK_NUM_ACCESS_FS as value. >>> * Updates access_masks_t to u32 to support network access actions. >>> * Refactors landlock internal functions to support network actions with >>> landlock_key/key_type/id types. >>> >>> Changes since v5: >>> * Gets rid of partial revert from landlock_add_rule >>> syscall. >>> * Formats code with clang-format-14. >>> >>> Changes since v4: >>> * Refactors landlock_create_ruleset() - splits ruleset and >>> masks checks. >>> * Refactors landlock_create_ruleset() and landlock mask >>> setters/getters to support two rule types. >>> * Refactors landlock_add_rule syscall add_rule_path_beneath >>> function by factoring out get_ruleset_from_fd() and >>> landlock_put_ruleset(). >>> >>> Changes since v3: >>> * Splits commit. >>> * Adds network rule support for internal landlock functions. >>> * Adds set_mask and get_mask for network. >>> * Adds rb_root root_net_port. >>> >>> --- >>> security/landlock/limits.h | 6 +++++- >>> security/landlock/ruleset.c | 38 +++++++++++++++++++++++++++++---- >>> security/landlock/ruleset.h | 41 ++++++++++++++++++++++++++++++++++-- >>> security/landlock/syscalls.c | 8 ++++++- >>> 4 files changed, 85 insertions(+), 8 deletions(-) >>> >>> diff --git a/security/landlock/limits.h b/security/landlock/limits.h >>> index bafb3b8dc677..8a1a6463c64e 100644 >>> --- a/security/landlock/limits.h >>> +++ b/security/landlock/limits.h >>> @@ -23,6 +23,10 @@ >>> #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) >>> #define LANDLOCK_SHIFT_ACCESS_FS 0 >>> >>> -/* 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_SHIFT_ACCESS_NET LANDLOCK_NUM_ACCESS_FS >>> >>> +/* clang-format on */ >>> #endif /* _SECURITY_LANDLOCK_LIMITS_H */ >>> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c >>> index 84fcd8eb30d4..442f212039df 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 >>> @@ -46,16 +47,21 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >>> } >>> >>> struct landlock_ruleset * >>> -landlock_create_ruleset(const access_mask_t fs_access_mask) >>> +landlock_create_ruleset(const access_mask_t fs_access_mask, >>> + const access_mask_t net_access_mask) >>> { >>> struct landlock_ruleset *new_ruleset; >>> >>> /* Informs about useless ruleset. */ >>> - if (!fs_access_mask) >>> + if (!fs_access_mask && !net_access_mask) >>> return ERR_PTR(-ENOMSG); >>> new_ruleset = create_ruleset(1); >>> - if (!IS_ERR(new_ruleset)) >>> + if (IS_ERR(new_ruleset)) >>> + return new_ruleset; >>> + if (fs_access_mask) >>> landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); >>> + if (net_access_mask) >>> + landlock_add_net_access_mask(new_ruleset, net_access_mask, 0); >>> return new_ruleset; >>> } >>> >>> @@ -73,6 +79,8 @@ static inline bool is_object_pointer(const enum landlock_key_type key_type) >>> switch (key_type) { >>> case LANDLOCK_KEY_INODE: >>> return true; >>> + case LANDLOCK_KEY_NET_PORT: >>> + return false; >>> } >>> WARN_ON_ONCE(1); >>> return false; >>> @@ -126,6 +134,9 @@ static inline struct rb_root *get_root(struct landlock_ruleset *const ruleset, >>> case LANDLOCK_KEY_INODE: >>> root = &ruleset->root_inode; >>> break; >>> + case LANDLOCK_KEY_NET_PORT: >>> + root = &ruleset->root_net_port; >>> + break; >>> } >>> if (WARN_ON_ONCE(!root)) >>> return ERR_PTR(-EINVAL); >>> @@ -154,7 +165,9 @@ static void build_check_ruleset(void) >>> BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); >>> BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); >>> BUILD_BUG_ON(access_masks < >>> - (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); >>> + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS) + >>> + (LANDLOCK_MASK_ACCESS_NET >>> + << LANDLOCK_SHIFT_ACCESS_NET)); >>> } >>> >>> /** >>> @@ -367,6 +380,11 @@ static int merge_ruleset(struct landlock_ruleset *const dst, >>> if (err) >>> goto out_unlock; >>> >>> + /* Merges the @src network port tree. */ >>> + err = merge_tree(dst, src, LANDLOCK_KEY_NET_PORT); >>> + if (err) >>> + goto out_unlock; >>> + >>> out_unlock: >>> mutex_unlock(&src->lock); >>> mutex_unlock(&dst->lock); >>> @@ -419,6 +437,11 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, >>> if (err) >>> goto out_unlock; >>> >>> + /* Copies the @parent network port tree. */ >>> + err = inherit_tree(parent, child, LANDLOCK_KEY_NET_PORT); >>> + if (err) >>> + goto out_unlock; >>> + >>> if (WARN_ON_ONCE(child->num_layers <= parent->num_layers)) { >>> err = -EINVAL; >>> goto out_unlock; >>> @@ -451,6 +474,9 @@ 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_KEY_INODE); >>> + rbtree_postorder_for_each_entry_safe(freeme, next, >>> + &ruleset->root_net_port, node) >>> + free_rule(freeme, LANDLOCK_KEY_NET_PORT); >>> put_hierarchy(ruleset->hierarchy); >>> kfree(ruleset); >>> } >>> @@ -640,6 +666,10 @@ access_mask_t init_layer_masks(const struct landlock_ruleset *const domain, >>> get_access_mask = landlock_get_fs_access_mask; >>> num_access = LANDLOCK_NUM_ACCESS_FS; >>> break; >>> + case LANDLOCK_KEY_NET_PORT: >>> + get_access_mask = landlock_get_net_access_mask; >>> + num_access = LANDLOCK_NUM_ACCESS_NET; >>> + break; >>> default: >>> WARN_ON_ONCE(1); >>> return 0; >>> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h >>> index 2083855bf42d..d456ee90b648 100644 >>> --- a/security/landlock/ruleset.h >>> +++ b/security/landlock/ruleset.h >>> @@ -26,7 +26,7 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); >>> static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); >>> >>> /* Ruleset access masks. */ >>> -typedef u16 access_masks_t; >>> +typedef u32 access_masks_t; >>> /* Makes sure all ruleset access rights can be stored. */ >>> static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); >> >> There is some fixes missing from my patch. >> >> >>> >>> @@ -66,6 +66,11 @@ enum landlock_key_type { >>> * keys. >>> */ >>> LANDLOCK_KEY_INODE = 1, >> >> >> #if IS_ENABLED(CONFIG_INET) >> >>> + /** >>> + * @LANDLOCK_KEY_NET_PORT: Type of &landlock_ruleset.root_net_port's >>> + * node keys. >>> + */ >>> + LANDLOCK_KEY_NET_PORT = 2, >> >> #endif /* IS_ENABLED(CONFIG_INET) */ >> >> And then all use of LANDLOCK_KEY_NET_PORT should be surrounded by the >> same check (but not directly in the net.c file). > > I checked the branch with your patches: tmp-net > (7d6cf40a6f81adf607ad3cc17aaa11e256beeea4), but I did not find #if > IS_ENABLED(CONFIG_INET) surrounding LANDLOCK_KEY_NET_PORT. You need to write that yourself. >> >> >>> }; >>> >>> /** >>> @@ -133,6 +138,12 @@ struct landlock_ruleset { >>> * reaches zero. >>> */ >>> struct rb_root root_inode; >> >> #if IS_ENABLED(CONFIG_INET) >> >>> + /** >>> + * @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. >>> + */ >> >> There is some fixes missing from my patch. Please explain everything >> that you didn't take. > > Sorry. I did merge your patch manually and did not tell the > difference here. Will be fixed You can use git diff to be sure to not miss some parts. BTW, tools such as git cherry-pick, read-tree, diff and "add -p" can save you some time. >> >> >>> + struct rb_root root_net_port; >> >> >> #endif /* IS_ENABLED(CONFIG_INET) */ >> >> And then all use of root_net_port should be surrounded by the same check. > > The same - I did not find #if IS_ENABLED(CONFIG_INET) surrounding > root_net_port in tmp-net (7d6cf40a6f81adf607ad3cc17aaa11e256beeea4) >> >> I think it should be OK to keep all other remaining network references >> though (e.g. access_masks and the ). > > Ok. Thanks. >> >> >>> /** >>> * @hierarchy: Enables hierarchy identification even when a parent >>> * domain vanishes. This is needed for the ptrace protection. >>> @@ -188,7 +199,8 @@ struct landlock_ruleset { >>> }; >>> >>> struct landlock_ruleset * >>> -landlock_create_ruleset(const access_mask_t access_mask); >>> +landlock_create_ruleset(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); >>> @@ -226,6 +238,21 @@ landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, >>> (fs_mask << LANDLOCK_SHIFT_ACCESS_FS); >>> } >>> >>> +/* A helper function to set a network mask. */ >> >> I already said that this comment is useless, and I removed it in my >> patch. Please take a closer look at reviews. > > Sorry. I missed that in your patch. Will be fixed. >> >> >>> +static inline void >>> +landlock_add_net_access_mask(struct landlock_ruleset *const ruleset, >>> + const access_mask_t net_access_mask, >>> + const u16 layer_level) >>> +{ >>> + access_mask_t net_mask = net_access_mask & LANDLOCK_MASK_ACCESS_NET; >>> + >>> + /* Should already be checked in sys_landlock_create_ruleset(). */ >>> + WARN_ON_ONCE(net_access_mask != net_mask); >>> + // TODO: Add tests to check "|=" and not "=" >>> + ruleset->access_masks[layer_level] |= >>> + (net_mask << LANDLOCK_SHIFT_ACCESS_NET); >>> +} >>> + >>> /* A helper function to get a filesystem mask. */ >>> static inline access_mask_t >>> landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, >>> @@ -236,6 +263,16 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, >>> LANDLOCK_MASK_ACCESS_FS; >>> } >>> >>> +/* A helper function to get a network mask. */ >>> +static inline access_mask_t >>> +landlock_get_net_access_mask(const struct landlock_ruleset *const ruleset, >>> + const u16 layer_level) >>> +{ >>> + return (ruleset->access_masks[layer_level] >> >>> + LANDLOCK_SHIFT_ACCESS_NET) & >>> + LANDLOCK_MASK_ACCESS_NET; >>> +} >>> + >> >> This hunk doesn't match my patch. > > Do you mean landlock_get_net_access_mask? If yes, there is no diff > with your patch here. I removed useless comments, please do a diff (and look at the changes in the commit messages). Some code also moved. >> >> >>> bool unmask_layers(const struct landlock_rule *const rule, >>> const access_mask_t access_request, >>> layer_mask_t (*const layer_masks)[], >>> diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c >>> index ffd5805eddd9..641155f6f6f8 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); >>> >>> -- >>> 2.25.1 >>> >> .