From patchwork Wed Jan 8 15:43:14 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= X-Patchwork-Id: 13931192 Received: from smtp-190e.mail.infomaniak.ch (smtp-190e.mail.infomaniak.ch [185.125.25.14]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 94B731FE44A for ; Wed, 8 Jan 2025 15:43:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.125.25.14 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736351039; cv=none; b=ndKG8zIYK+tMA5i9M2fSDCKBiFU97p/70PFIle1eZ7caAhDMu/VsInW69ecXLtKZxiMC/ReTSpi3iuiZUA7BdJjJIsdpZnpChfIxlOHT4Z2g+xKiETKrvybYDLNNtgGGJtcOmTS45WvNq8xiNCprRY8sj7/BvBQz+3p4r+yRtwI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736351039; c=relaxed/simple; bh=pbjs421Pky9glSBPHXWUS1xMZ9hfuvzC41AX1/E76bQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qSai4qIcXcoSi490C9UUA6FpzfgEMCTR7tVegSbpxbO06LsHI6KdhV38+QKmff4k2FBpuv72bYvNbPc0Vk5XxnX/X0EzRlWAGMaWMrpZD2r7PYIv1ihstMzD65ZpQS337LLBsMQRBWQK5rWJ3+jy7h/InnVW4ZhftcmspXlqem8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=digikod.net; spf=pass smtp.mailfrom=digikod.net; dkim=pass (1024-bit key) header.d=digikod.net header.i=@digikod.net header.b=l6GmoPQ7; arc=none smtp.client-ip=185.125.25.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=digikod.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=digikod.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=digikod.net header.i=@digikod.net header.b="l6GmoPQ7" Received: from smtp-3-0001.mail.infomaniak.ch (unknown [IPv6:2001:1600:4:17::246c]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4YSsf30x1Bz9s9; Wed, 8 Jan 2025 16:43:55 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=digikod.net; s=20191114; t=1736351035; bh=f4tHQfJHpRqEk9p+KaoskKp0MCYGZFL6TV5oGOIgc5Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l6GmoPQ72Us7PhF3owCE6mG8SfAdRnQMjDmn0sWMO/XDhJJIZGxz/ncbJajYcSLvR NJ9WcYHAu9SVZ82q/D+yJC6taeexeZWvHB109XzBgIL7A7fE8BpYQxBOvZnWqSrvzl VQtqUwx+TtKAwsLzkf/0N2Q0CIKvweyuO9ds68uc= Received: from unknown by smtp-3-0001.mail.infomaniak.ch (Postfix) with ESMTPA id 4YSsf22RwSzLFX; Wed, 8 Jan 2025 16:43:54 +0100 (CET) From: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= To: Eric Paris , Paul Moore , =?utf-8?q?G=C3=BCnther_Noack?= , "Serge E . Hallyn" Cc: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= , Ben Scarlato , Casey Schaufler , Charles Zaffery , Daniel Burgener , Francis Laniel , James Morris , Jann Horn , Jeff Xu , Jorge Lucangeli Obes , Kees Cook , Konstantin Meskhidze , Matt Bobrowski , Mikhail Ivanov , Phil Sutter , Praveen K Paladugu , Robert Salvet , Shervin Oloumi , Song Liu , Tahera Fahimi , Tyler Hicks , audit@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v4 06/30] landlock: Simplify initially denied access rights Date: Wed, 8 Jan 2025 16:43:14 +0100 Message-ID: <20250108154338.1129069-7-mic@digikod.net> In-Reply-To: <20250108154338.1129069-1-mic@digikod.net> References: <20250108154338.1129069-1-mic@digikod.net> Precedence: bulk X-Mailing-List: audit@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Infomaniak-Routing: alpha Upgrade domain's handled access masks when creating a domain from a ruleset, instead of converting them at runtime. This is more consistent and helps with audit support. Cc: Günther Noack Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20250108154338.1129069-7-mic@digikod.net --- Changes since v2: - New patch. --- security/landlock/access.h | 17 ++++++++++++++++- security/landlock/fs.c | 10 +--------- security/landlock/ruleset.c | 3 ++- 3 files changed, 19 insertions(+), 11 deletions(-) diff --git a/security/landlock/access.h b/security/landlock/access.h index 9ee4b30a87e6..74fd8f399fbd 100644 --- a/security/landlock/access.h +++ b/security/landlock/access.h @@ -20,7 +20,8 @@ /* * All access rights that are denied by default whether they are handled or not * by a ruleset/layer. This must be ORed with all ruleset->access_masks[] - * entries when we need to get the absolute handled access masks. + * entries when we need to get the absolute handled access masks, see + * landlock_upgrade_handled_access_masks(). */ /* clang-format off */ #define _LANDLOCK_ACCESS_FS_INITIALLY_DENIED ( \ @@ -59,4 +60,18 @@ typedef u16 layer_mask_t; /* Makes sure all layers can be checked. */ static_assert(BITS_PER_TYPE(layer_mask_t) >= LANDLOCK_MAX_NUM_LAYERS); +/* Upgrades with all initially denied by default access rights. */ +static inline struct access_masks +landlock_upgrade_handled_access_masks(struct access_masks access_masks) +{ + /* + * All access rights that are denied by default whether they are + * explicitly handled or not. + */ + if (access_masks.fs) + access_masks.fs |= _LANDLOCK_ACCESS_FS_INITIALLY_DENIED; + + return access_masks; +} + #endif /* _SECURITY_LANDLOCK_ACCESS_H */ diff --git a/security/landlock/fs.c b/security/landlock/fs.c index 3da5f1945158..9779170d9199 100644 --- a/security/landlock/fs.c +++ b/security/landlock/fs.c @@ -389,14 +389,6 @@ static bool is_nouser_or_private(const struct dentry *dentry) unlikely(IS_PRIVATE(d_backing_inode(dentry)))); } -static access_mask_t -get_handled_fs_accesses(const struct landlock_ruleset *const domain) -{ - /* Handles all initially denied by default access rights. */ - return landlock_union_access_masks(domain).fs | - _LANDLOCK_ACCESS_FS_INITIALLY_DENIED; -} - static const struct access_masks any_fs = { .fs = ~0, }; @@ -788,7 +780,7 @@ static bool is_access_to_paths_allowed( * a superset of the meaningful requested accesses). */ access_masked_parent1 = access_masked_parent2 = - get_handled_fs_accesses(domain); + landlock_union_access_masks(domain).fs; is_dom_check = true; } else { if (WARN_ON_ONCE(dentry_child1 || dentry_child2)) diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c index cae69f2f01d9..dbc528f5f3b7 100644 --- a/security/landlock/ruleset.c +++ b/security/landlock/ruleset.c @@ -385,7 +385,8 @@ static int merge_ruleset(struct landlock_ruleset *const dst, err = -EINVAL; goto out_unlock; } - dst->access_masks[dst->num_layers - 1] = src->access_masks[0]; + dst->access_masks[dst->num_layers - 1] = + landlock_upgrade_handled_access_masks(src->access_masks[0]); /* Merges the @src inode tree. */ err = merge_tree(dst, src, LANDLOCK_KEY_INODE);