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 407FBC678D5 for ; Tue, 21 Feb 2023 18:07:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229867AbjBUSH2 (ORCPT ); Tue, 21 Feb 2023 13:07:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230175AbjBUSHZ (ORCPT ); Tue, 21 Feb 2023 13:07:25 -0500 Received: from smtp-bc0d.mail.infomaniak.ch (smtp-bc0d.mail.infomaniak.ch [IPv6:2001:1600:3:17::bc0d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D489301A6 for ; Tue, 21 Feb 2023 10:07:20 -0800 (PST) Received: from smtp-3-0000.mail.infomaniak.ch (unknown [10.4.36.107]) by smtp-2-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4PLnLZ4wkwzMrDZH; Tue, 21 Feb 2023 19:07:18 +0100 (CET) Received: from unknown by smtp-3-0000.mail.infomaniak.ch (Postfix) with ESMTPA id 4PLnLY70qyz1c9S; Tue, 21 Feb 2023 19:07:17 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=digikod.net; s=20191114; t=1677002838; bh=zXJIin2CHxFo9lK7CQ2jXmL3VUqX/fQEaz+z1MwBk38=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ogncoP81p7OvYpG5VwzasszV13hStgg5LIhSdMh6BP3WvCelY5iUubUU/7hLnSb0s U/iWUR0WjR7u/cupuwtt0zt9IuJXMQo/2j3ye8+f2YJffmsB/AxjSQr0mdLdLoRu22 AvUkSaR2g7h1xg8nLUsx8EeOHxL20qPN77s6uZ7c= Message-ID: <3e9ef23b-c599-6ba1-1d18-a615f53b6e7b@digikod.net> Date: Tue, 21 Feb 2023 19:07:17 +0100 MIME-Version: 1.0 User-Agent: Subject: Re: [PATCH v9 06/12] landlock: Refactor _unmask_layers() and _init_layer_masks() Content-Language: en-US To: Konstantin Meskhidze Cc: willemdebruijn.kernel@gmail.com, gnoack3000@gmail.com, linux-security-module@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, yusongping@huawei.com, artem.kuzin@huawei.com References: <20230116085818.165539-1-konstantin.meskhidze@huawei.com> <20230116085818.165539-7-konstantin.meskhidze@huawei.com> From: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= In-Reply-To: <20230116085818.165539-7-konstantin.meskhidze@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Infomaniak-Routing: alpha Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org It's not "_unmask_layers() and _init_layer_masks()": there is no "_" prefixes. Using "landlock_unmask_layers()" in the subject would be too long, so you can replace it with "landlock: Refactor layer helpers". For consistency, you can change the previous patch's subject to "landlock: Move and rename layer helpers" Anyway, please send a new patch series. Most of the kernel code should be good and I could then push it to -next for testing while reviewing the last parts. On 16/01/2023 09:58, Konstantin Meskhidze wrote: > Add new key_type argument to the landlock_init_layer_masks() helper. > Add a masks_array_size argument to the landlock_unmask_layers() helper. > These modifications support implementing new rule types in the next > Landlock versions. > > Signed-off-by: Mickaël Salaün > Signed-off-by: Konstantin Meskhidze > --- > > Changes since v8: > * None. > > Changes since v7: > * Refactors commit message, adds a co-developer. > * Minor fixes. > > Changes since v6: > * Removes masks_size attribute from init_layer_masks(). > * Refactors init_layer_masks() with new landlock_key_type. > > Changes since v5: > * Splits commit. > * Formats code with clang-format-14. > > Changes since v4: > * Refactors init_layer_masks(), get_handled_accesses() > and unmask_layers() functions to support multiple rule types. > * Refactors landlock_get_fs_access_mask() function with > LANDLOCK_MASK_ACCESS_FS mask. > > Changes since v3: > * Splits commit. > * Refactors landlock_unmask_layers functions. > > --- > security/landlock/fs.c | 43 ++++++++++++++++-------------- > security/landlock/ruleset.c | 52 ++++++++++++++++++++++++++----------- > security/landlock/ruleset.h | 17 ++++++------ > 3 files changed, 70 insertions(+), 42 deletions(-) > > diff --git a/security/landlock/fs.c b/security/landlock/fs.c > index 73a7399f93ba..a73dbd3f9ddb 100644 > --- a/security/landlock/fs.c > +++ b/security/landlock/fs.c > @@ -441,20 +441,22 @@ static bool is_access_to_paths_allowed( > } > > if (unlikely(dentry_child1)) { > - landlock_unmask_layers(find_rule(domain, dentry_child1), > - landlock_init_layer_masks( > - domain, LANDLOCK_MASK_ACCESS_FS, > - &_layer_masks_child1), > - &_layer_masks_child1); > + landlock_unmask_layers( > + find_rule(domain, dentry_child1), > + landlock_init_layer_masks( > + domain, LANDLOCK_MASK_ACCESS_FS, > + &_layer_masks_child1, LANDLOCK_KEY_INODE), > + &_layer_masks_child1, ARRAY_SIZE(_layer_masks_child1)); > layer_masks_child1 = &_layer_masks_child1; > child1_is_directory = d_is_dir(dentry_child1); > } > if (unlikely(dentry_child2)) { > - landlock_unmask_layers(find_rule(domain, dentry_child2), > - landlock_init_layer_masks( > - domain, LANDLOCK_MASK_ACCESS_FS, > - &_layer_masks_child2), > - &_layer_masks_child2); > + landlock_unmask_layers( > + find_rule(domain, dentry_child2), > + landlock_init_layer_masks( > + domain, LANDLOCK_MASK_ACCESS_FS, > + &_layer_masks_child2, LANDLOCK_KEY_INODE), > + &_layer_masks_child2, ARRAY_SIZE(_layer_masks_child2)); > layer_masks_child2 = &_layer_masks_child2; > child2_is_directory = d_is_dir(dentry_child2); > } > @@ -507,14 +509,15 @@ static bool is_access_to_paths_allowed( > > rule = find_rule(domain, walker_path.dentry); > allowed_parent1 = landlock_unmask_layers( > - rule, access_masked_parent1, layer_masks_parent1); > + rule, access_masked_parent1, layer_masks_parent1, > + ARRAY_SIZE(*layer_masks_parent1)); > allowed_parent2 = landlock_unmask_layers( > - rule, access_masked_parent2, layer_masks_parent2); > + rule, access_masked_parent2, layer_masks_parent2, > + ARRAY_SIZE(*layer_masks_parent2)); > > /* Stops when a rule from each layer grants access. */ > if (allowed_parent1 && allowed_parent2) > break; > - > jump_up: > if (walker_path.dentry == walker_path.mnt->mnt_root) { > if (follow_up(&walker_path)) { > @@ -553,8 +556,8 @@ static int check_access_path(const struct landlock_ruleset *const domain, > { > layer_mask_t layer_masks[LANDLOCK_NUM_ACCESS_FS] = {}; > > - access_request = > - landlock_init_layer_masks(domain, access_request, &layer_masks); > + access_request = landlock_init_layer_masks( > + domain, access_request, &layer_masks, LANDLOCK_KEY_INODE); > if (is_access_to_paths_allowed(domain, path, access_request, > &layer_masks, NULL, 0, NULL, NULL)) > return 0; > @@ -640,7 +643,8 @@ static bool collect_domain_accesses( > return true; > > access_dom = landlock_init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS, > - layer_masks_dom); > + layer_masks_dom, > + LANDLOCK_KEY_INODE); > > dget(dir); > while (true) { > @@ -648,7 +652,8 @@ static bool collect_domain_accesses( > > /* Gets all layers allowing all domain accesses. */ > if (landlock_unmask_layers(find_rule(domain, dir), access_dom, > - layer_masks_dom)) { > + layer_masks_dom, > + ARRAY_SIZE(*layer_masks_dom))) { > /* > * Stops when all handled accesses are allowed by at > * least one rule in each layer. > @@ -763,7 +768,7 @@ static int current_check_refer_path(struct dentry *const old_dentry, > */ > access_request_parent1 = landlock_init_layer_masks( > dom, access_request_parent1 | access_request_parent2, > - &layer_masks_parent1); > + &layer_masks_parent1, LANDLOCK_KEY_INODE); > if (is_access_to_paths_allowed( > dom, new_dir, access_request_parent1, > &layer_masks_parent1, NULL, 0, NULL, NULL)) > @@ -1139,7 +1144,7 @@ static int hook_file_open(struct file *const file) > if (is_access_to_paths_allowed( > dom, &file->f_path, > landlock_init_layer_masks(dom, full_access_request, > - &layer_masks), > + &layer_masks, LANDLOCK_KEY_INODE), > &layer_masks, NULL, 0, NULL, NULL)) { > allowed_access = full_access_request; > } else { > diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c > index 22590cac3d56..9748b54b42fe 100644 > --- a/security/landlock/ruleset.c > +++ b/security/landlock/ruleset.c > @@ -576,14 +576,15 @@ landlock_find_rule(const struct landlock_ruleset *const ruleset, > /* > * @layer_masks is read and may be updated according to the access request and > * the matching rule. > + * @masks_array_size must be equal to ARRAY_SIZE(*layer_masks). > * > * Returns true if the request is allowed (i.e. relevant layer masks for the > * request are empty). > */ > -bool landlock_unmask_layers( > - const struct landlock_rule *const rule, > - const access_mask_t access_request, > - layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]) > +bool landlock_unmask_layers(const struct landlock_rule *const rule, > + const access_mask_t access_request, > + layer_mask_t (*const layer_masks)[], > + const size_t masks_array_size) > { > size_t layer_level; > > @@ -615,8 +616,7 @@ bool landlock_unmask_layers( > * requested access. > */ > is_empty = true; > - for_each_set_bit(access_bit, &access_req, > - ARRAY_SIZE(*layer_masks)) { > + for_each_set_bit(access_bit, &access_req, masks_array_size) { > if (layer->access & BIT_ULL(access_bit)) > (*layer_masks)[access_bit] &= ~layer_bit; > is_empty = is_empty && !(*layer_masks)[access_bit]; > @@ -627,6 +627,10 @@ bool landlock_unmask_layers( > return false; > } > > +typedef access_mask_t > +get_access_mask_t(const struct landlock_ruleset *const ruleset, > + const u16 layer_level); > + > /* > * init_layer_masks - Initialize layer masks from an access request > * > @@ -636,19 +640,34 @@ bool landlock_unmask_layers( > * @domain: The domain that defines the current restrictions. > * @access_request: The requested access rights to check. > * @layer_masks: The layer masks to populate. > + * @key_type: The key type to switch between access masks of different types. > * > * Returns: An access mask where each access right bit is set which is handled > * in any of the active layers in @domain. > */ > -access_mask_t landlock_init_layer_masks( > - const struct landlock_ruleset *const domain, > - const access_mask_t access_request, > - layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]) > +access_mask_t > +landlock_init_layer_masks(const struct landlock_ruleset *const domain, > + const access_mask_t access_request, > + layer_mask_t (*const layer_masks)[], > + const enum landlock_key_type key_type) > { > access_mask_t handled_accesses = 0; > - size_t layer_level; > + size_t layer_level, num_access; > + get_access_mask_t *get_access_mask; > + > + switch (key_type) { > + case LANDLOCK_KEY_INODE: > + get_access_mask = landlock_get_fs_access_mask; > + num_access = LANDLOCK_NUM_ACCESS_FS; > + break; > + default: > + WARN_ON_ONCE(1); > + return 0; > + } > + > + memset(layer_masks, 0, > + array_size(sizeof((*layer_masks)[0]), num_access)); > > - memset(layer_masks, 0, sizeof(*layer_masks)); > /* An empty access request can happen because of O_WRONLY | O_RDWR. */ > if (!access_request) > return 0; > @@ -658,10 +677,13 @@ access_mask_t landlock_init_layer_masks( > const unsigned long access_req = access_request; > unsigned long access_bit; > > - for_each_set_bit(access_bit, &access_req, > - ARRAY_SIZE(*layer_masks)) { > + for_each_set_bit(access_bit, &access_req, num_access) { > + /* > + * Artificially handles all initially denied by default > + * access rights. > + */ > if (BIT_ULL(access_bit) & > - landlock_get_fs_access_mask(domain, layer_level)) { > + get_access_mask(domain, layer_level)) { > (*layer_masks)[access_bit] |= > BIT_ULL(layer_level); > handled_accesses |= BIT_ULL(access_bit); > diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h > index 60a3c4d4d961..77349764e111 100644 > --- a/security/landlock/ruleset.h > +++ b/security/landlock/ruleset.h > @@ -266,14 +266,15 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, > return landlock_get_raw_fs_access_mask(ruleset, layer_level) | > ACCESS_FS_INITIALLY_DENIED; > } > -bool landlock_unmask_layers( > - const struct landlock_rule *const rule, > - const access_mask_t access_request, > - layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]); > +bool landlock_unmask_layers(const struct landlock_rule *const rule, > + const access_mask_t access_request, > + layer_mask_t (*const layer_masks)[], > + const size_t masks_array_size); > > -access_mask_t landlock_init_layer_masks( > - const struct landlock_ruleset *const domain, > - const access_mask_t access_request, > - layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]); > +access_mask_t > +landlock_init_layer_masks(const struct landlock_ruleset *const domain, > + const access_mask_t access_request, > + layer_mask_t (*const layer_masks)[], > + const enum landlock_key_type key_type); > > #endif /* _SECURITY_LANDLOCK_RULESET_H */