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 DC00EC433F5 for ; Wed, 9 Mar 2022 13:45:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232244AbiCINqS (ORCPT ); Wed, 9 Mar 2022 08:46:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231219AbiCINqM (ORCPT ); Wed, 9 Mar 2022 08:46:12 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3CF5917B88E; Wed, 9 Mar 2022 05:45:13 -0800 (PST) Received: from fraeml704-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4KDD2g48CVz67bVT; Wed, 9 Mar 2022 21:44:43 +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 15.1.2308.21; Wed, 9 Mar 2022 14:45:10 +0100 From: Konstantin Meskhidze To: CC: , , , , , , Subject: [RFC PATCH v4 02/15] landlock: filesystem access mask helpers Date: Wed, 9 Mar 2022 21:44:46 +0800 Message-ID: <20220309134459.6448-3-konstantin.meskhidze@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220309134459.6448-1-konstantin.meskhidze@huawei.com> References: <20220309134459.6448-1-konstantin.meskhidze@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII 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 patch adds filesystem helper functions to set and get filesystem mask. Also the modification adds a helper structure landlock_access_mask to support managing multiple access mask. Signed-off-by: Konstantin Meskhidze --- Changes since v3: * Split commit. * Add get_mask, set_mask helpers for filesystem. * Add new struct landlock_access_mask. --- security/landlock/fs.c | 4 ++-- security/landlock/ruleset.c | 20 +++++++++++++++++--- security/landlock/ruleset.h | 19 ++++++++++++++++++- security/landlock/syscalls.c | 9 ++++++--- 4 files changed, 43 insertions(+), 9 deletions(-) diff --git a/security/landlock/fs.c b/security/landlock/fs.c index d727bdab7840..97f5c455f5a7 100644 --- a/security/landlock/fs.c +++ b/security/landlock/fs.c @@ -163,7 +163,7 @@ int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, return -EINVAL; /* Transforms relative access rights to absolute ones. */ - access_rights |= LANDLOCK_MASK_ACCESS_FS & ~ruleset->access_masks[0]; + access_rights |= LANDLOCK_MASK_ACCESS_FS & ~landlock_get_fs_access_mask(ruleset, 0); object = get_inode_object(d_backing_inode(path->dentry)); if (IS_ERR(object)) return PTR_ERR(object); @@ -252,7 +252,7 @@ static int check_access_path(const struct landlock_ruleset *const domain, /* Saves all layers handling a subset of requested accesses. */ layer_mask = 0; for (i = 0; i < domain->num_layers; i++) { - if (domain->access_masks[i] & access_request) + if (landlock_get_fs_access_mask(domain, i) & access_request) layer_mask |= BIT_ULL(i); } /* An access request not handled by the domain is allowed. */ diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c index 78341a0538de..a6212b752549 100644 --- a/security/landlock/ruleset.c +++ b/security/landlock/ruleset.c @@ -44,16 +44,30 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) return new_ruleset; } -struct landlock_ruleset *landlock_create_ruleset(const u32 access_mask) +/* A helper function to set a filesystem mask */ +void landlock_set_fs_access_mask(struct landlock_ruleset *ruleset, + const struct landlock_access_mask *access_mask_set, + u16 mask_level) +{ + ruleset->access_masks[mask_level] = access_mask_set->fs; +} + +/* A helper function to get a filesystem mask */ +u32 landlock_get_fs_access_mask(const struct landlock_ruleset *ruleset, u16 mask_level) +{ + return ruleset->access_masks[mask_level]; +} + +struct landlock_ruleset *landlock_create_ruleset(const struct landlock_access_mask *access_mask_set) { struct landlock_ruleset *new_ruleset; /* Informs about useless ruleset. */ - if (!access_mask) + if (!access_mask_set->fs) return ERR_PTR(-ENOMSG); new_ruleset = create_ruleset(1); if (!IS_ERR(new_ruleset)) - new_ruleset->access_masks[0] = access_mask; + landlock_set_fs_access_mask(new_ruleset, access_mask_set, 0); return new_ruleset; } diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h index 32d90ce72428..bc87e5f787f7 100644 --- a/security/landlock/ruleset.h +++ b/security/landlock/ruleset.h @@ -16,6 +16,16 @@ #include "object.h" +/** + * struct landlock_access_mask - A helper structure to handle different mask types + */ +struct landlock_access_mask { + /** + * @fs: Filesystem access mask. + */ + u16 fs; +}; + /** * struct landlock_layer - Access rights for a given layer */ @@ -140,7 +150,8 @@ struct landlock_ruleset { }; }; -struct landlock_ruleset *landlock_create_ruleset(const u32 access_mask); +struct landlock_ruleset *landlock_create_ruleset(const struct landlock_access_mask + *access_mask_set); void landlock_put_ruleset(struct landlock_ruleset *const ruleset); void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); @@ -162,4 +173,10 @@ static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) refcount_inc(&ruleset->usage); } +void landlock_set_fs_access_mask(struct landlock_ruleset *ruleset, + const struct landlock_access_mask *access_mask_set, + u16 mask_level); + +u32 landlock_get_fs_access_mask(const struct landlock_ruleset *ruleset, u16 mask_level); + #endif /* _SECURITY_LANDLOCK_RULESET_H */ diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c index f1d86311df7e..5931b666321d 100644 --- a/security/landlock/syscalls.c +++ b/security/landlock/syscalls.c @@ -159,6 +159,7 @@ SYSCALL_DEFINE3(landlock_create_ruleset, { struct landlock_ruleset_attr ruleset_attr; struct landlock_ruleset *ruleset; + struct landlock_access_mask access_mask_set = {.fs = 0}; int err, ruleset_fd; /* Build-time checks. */ @@ -185,9 +186,10 @@ SYSCALL_DEFINE3(landlock_create_ruleset, if ((ruleset_attr.handled_access_fs | LANDLOCK_MASK_ACCESS_FS) != LANDLOCK_MASK_ACCESS_FS) return -EINVAL; + access_mask_set.fs = ruleset_attr.handled_access_fs; /* Checks arguments and transforms to kernel struct. */ - ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs); + ruleset = landlock_create_ruleset(&access_mask_set); if (IS_ERR(ruleset)) return PTR_ERR(ruleset); @@ -343,8 +345,9 @@ SYSCALL_DEFINE4(landlock_add_rule, * Checks that allowed_access matches the @ruleset constraints * (ruleset->access_masks[0] is automatically upgraded to 64-bits). */ - if ((path_beneath_attr.allowed_access | ruleset->access_masks[0]) != - ruleset->access_masks[0]) { + + 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; } -- 2.25.1