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 71F28C6FD19 for ; Mon, 6 Mar 2023 07:52:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229693AbjCFHwn (ORCPT ); Mon, 6 Mar 2023 02:52:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229519AbjCFHwn (ORCPT ); Mon, 6 Mar 2023 02:52:43 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C3A81F483; Sun, 5 Mar 2023 23:52:41 -0800 (PST) Received: from lhrpeml500004.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4PVW2M0V5cz682sK; Mon, 6 Mar 2023 15:50:03 +0800 (CST) Received: from [10.123.123.126] (10.123.123.126) by lhrpeml500004.china.huawei.com (7.191.163.9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Mon, 6 Mar 2023 07:52:38 +0000 Message-ID: <25ffc506-82cc-848c-6288-ae3955220edb@huawei.com> Date: Mon, 6 Mar 2023 10:52:37 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.4.1 Subject: Re: [PATCH v9 06/12] landlock: Refactor _unmask_layers() and _init_layer_masks() Content-Language: ru To: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= CC: , , , , , , References: <20230116085818.165539-1-konstantin.meskhidze@huawei.com> <20230116085818.165539-7-konstantin.meskhidze@huawei.com> <3e9ef23b-c599-6ba1-1d18-a615f53b6e7b@digikod.net> From: "Konstantin Meskhidze (A)" In-Reply-To: <3e9ef23b-c599-6ba1-1d18-a615f53b6e7b@digikod.net> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.123.123.126] X-ClientProxiedBy: lhrpeml500003.china.huawei.com (7.191.162.67) To lhrpeml500004.china.huawei.com (7.191.163.9) X-CFilter-Loop: Reflected Precedence: bulk List-ID: 2/21/2023 9:07 PM, Mickaël Salaün пишет: > 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. Hi, Mickaël. I was on a short vacation. Sorry for late reply. I will reply your review and send a new patch ASAP. Regards, Konstantin > > > 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 */ > .