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 5EE84C46467 for ; Mon, 28 Nov 2022 03:30:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229873AbiK1Daj (ORCPT ); Sun, 27 Nov 2022 22:30:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229671AbiK1Dai (ORCPT ); Sun, 27 Nov 2022 22:30:38 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7BC99C740; Sun, 27 Nov 2022 19:30:37 -0800 (PST) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4NL9vv1x6Jz67NRr; Mon, 28 Nov 2022 11:30:19 +0800 (CST) Received: from lhrpeml500004.china.huawei.com (7.191.163.9) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Mon, 28 Nov 2022 04:30:35 +0100 Received: from [10.122.132.241] (10.122.132.241) 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 15.1.2375.34; Mon, 28 Nov 2022 03:30:34 +0000 Message-ID: Date: Mon, 28 Nov 2022 06:30:33 +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 v8 05/12] landlock: Refactor unmask_layers() and init_layer_masks() Content-Language: ru To: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= CC: , , , , , References: <20221021152644.155136-1-konstantin.meskhidze@huawei.com> <20221021152644.155136-6-konstantin.meskhidze@huawei.com> From: "Konstantin Meskhidze (A)" In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.122.132.241] X-ClientProxiedBy: lhrpeml100003.china.huawei.com (7.191.160.210) To lhrpeml500004.china.huawei.com (7.191.163.9) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 11/17/2022 9:42 PM, Mickaël Salaün пишет: > > On 21/10/2022 17:26, Konstantin Meskhidze wrote: >> Adds new key_type argument to init_layer_masks() helper. > > Add a new key_type argument to the… > >> Adds masks_array_size argument to unmask_layers() helper. > > Add a masks_array_size argument to the… > > > The name of these helpers need to be prefixed with "landlock_". > > Thanks. Will be Fixed. >> These modifications support implementing new rule types in the next >> Landlock versions. >> >> Co-developed-by: Mickaël Salaün > > Signed-off-by: Mickaël Salaün Got it. > >> Signed-off-by: Konstantin Meskhidze >> --- >> >> 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 | 36 ++++++++++++++++++------------- >> security/landlock/ruleset.c | 42 ++++++++++++++++++++++++++----------- >> security/landlock/ruleset.h | 11 +++++----- >> 3 files changed, 58 insertions(+), 31 deletions(-) >> >> diff --git a/security/landlock/fs.c b/security/landlock/fs.c >> index 240e42a8f788..fe76a11483f8 100644 >> --- a/security/landlock/fs.c >> +++ b/security/landlock/fs.c >> @@ -435,16 +435,20 @@ static bool is_access_to_paths_allowed( >> if (unlikely(dentry_child1)) { >> unmask_layers(find_rule(domain, dentry_child1), >> init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS, >> - &_layer_masks_child1), >> - &_layer_masks_child1); >> + &_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)) { >> unmask_layers(find_rule(domain, dentry_child2), >> init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS, >> - &_layer_masks_child2), >> - &_layer_masks_child2); >> + &_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); >> } >> @@ -496,15 +500,16 @@ static bool is_access_to_paths_allowed( >> } >> >> rule = find_rule(domain, walker_path.dentry); >> - allowed_parent1 = unmask_layers(rule, access_masked_parent1, >> - layer_masks_parent1); >> - allowed_parent2 = unmask_layers(rule, access_masked_parent2, >> - layer_masks_parent2); >> + allowed_parent1 = unmask_layers( >> + rule, access_masked_parent1, layer_masks_parent1, >> + ARRAY_SIZE(*layer_masks_parent1)); >> + allowed_parent2 = unmask_layers( >> + 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)) { >> @@ -543,7 +548,8 @@ static inline int check_access_path(const struct landlock_ruleset *const domain, >> { >> layer_mask_t layer_masks[LANDLOCK_NUM_ACCESS_FS] = {}; >> >> - access_request = init_layer_masks(domain, access_request, &layer_masks); >> + access_request = 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; >> @@ -630,7 +636,7 @@ static bool collect_domain_accesses( >> return true; >> >> access_dom = init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS, >> - layer_masks_dom); >> + layer_masks_dom, LANDLOCK_KEY_INODE); >> >> dget(dir); >> while (true) { >> @@ -638,7 +644,8 @@ static bool collect_domain_accesses( >> >> /* Gets all layers allowing all domain accesses. */ >> if (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. >> @@ -754,7 +761,7 @@ static int current_check_refer_path(struct dentry *const old_dentry, >> */ >> access_request_parent1 = 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)) >> @@ -1131,7 +1138,8 @@ static int hook_file_open(struct file *const file) >> >> if (is_access_to_paths_allowed( >> dom, &file->f_path, >> - init_layer_masks(dom, full_access_request, &layer_masks), >> + init_layer_masks(dom, full_access_request, &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 02ab14439c43..c7cf54ba4f6d 100644 >> --- a/security/landlock/ruleset.c >> +++ b/security/landlock/ruleset.c >> @@ -576,13 +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 unmask_layers(const struct landlock_rule *const rule, >> const access_mask_t access_request, >> - layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]) >> + layer_mask_t (*const layer_masks)[], >> + const size_t masks_array_size) >> { >> size_t layer_level; >> >> @@ -614,8 +616,7 @@ bool unmask_layers(const struct landlock_rule *const rule, >> * 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]; >> @@ -626,6 +627,10 @@ bool unmask_layers(const struct landlock_rule *const rule, >> 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 >> * >> @@ -635,19 +640,33 @@ bool unmask_layers(const struct landlock_rule *const rule, >> * @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 >> -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 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; >> @@ -657,14 +676,13 @@ init_layer_masks(const struct landlock_ruleset *const domain, >> 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) | >> ACCESS_INITIALLY_DENIED)) { >> (*layer_masks)[access_bit] |= >> BIT_ULL(layer_level); >> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h >> index 50baff4fcbb4..d9eb79ea9a89 100644 >> --- a/security/landlock/ruleset.h >> +++ b/security/landlock/ruleset.h >> @@ -259,11 +259,12 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, >> >> bool unmask_layers(const struct landlock_rule *const rule, >> const access_mask_t access_request, >> - layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]); >> + layer_mask_t (*const layer_masks)[], >> + const size_t masks_array_size); >> >> -access_mask_t >> -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 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 */ >> -- >> 2.25.1 >> > .