From patchwork Fri Nov 22 14:33:36 2024 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: 13883258 Received: from smtp-bc0a.mail.infomaniak.ch (smtp-bc0a.mail.infomaniak.ch [45.157.188.10]) (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 AB60D13CA93 for ; Fri, 22 Nov 2024 14:40:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.157.188.10 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732286413; cv=none; b=qgioBGC/6SotcP+vrq9GvxWl1wPBWQm0ih88Fi/DaLI4FsD/FpSP7FICpFLpASPMJBgEaaE/eV5IYDGOtJsHdceIaynxGn/VLlvrBsOzHmfEE3+9A9QZfGIu8dm8sdIyxpHX5G23z1MjcJBvHhhrvCGxbUnLvxaXioTWkIWtyL8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732286413; c=relaxed/simple; bh=9Fxkj6Lw7DP1eAfNHnWrp7Twfjs6P7rVD5OBZe4cpq8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=mCHni4SUrcUEFWEvfPOEP3yf9S35wJZIJ8RVMcpsD6N6vkfWvm7253Uajje2EQbieKn2sb/LwpyXUvUgKlD3BH32LXsPEajbzRIeNEFOZzAyrqyqgZebppGaJvitwm8uWz7Lu8sXXuj6LEdQ0gylEkXbLB8VHcOdqJ3LwS10F0M= 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=q6BM95T0; arc=none smtp.client-ip=45.157.188.10 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="q6BM95T0" Received: from smtp-3-0000.mail.infomaniak.ch (smtp-3-0000.mail.infomaniak.ch [10.4.36.107]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4XvyKG6yVGzlKF; Fri, 22 Nov 2024 15:34:10 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=digikod.net; s=20191114; t=1732286050; bh=w3WVR4dmJCr/E++3tly2leydnVO6iM/bONHgj5qQ1yI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q6BM95T0+P8uMIKRgmgG7gxiJuT4hmcDLlWAlHYvGEL7lgBaMIdIKUH8wkHbEJdK5 BlroYM60s3HtzWnhD59eIRDiFFftfL//m0J8IlkjXv2wBX7N2fkQUARVW3O9aXMPf9 RPbomBAvJwrMnUAnIG7swAf5t/VavRlx0Iwzqx9o= Received: from unknown by smtp-3-0000.mail.infomaniak.ch (Postfix) with ESMTPA id 4XvyKG274Lzm5q; Fri, 22 Nov 2024 15:34:10 +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 , 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 , audit@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v3 06/23] landlock: Simplify initially denied access rights Date: Fri, 22 Nov 2024 15:33:36 +0100 Message-ID: <20241122143353.59367-7-mic@digikod.net> In-Reply-To: <20241122143353.59367-1-mic@digikod.net> References: <20241122143353.59367-1-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/20241122143353.59367-7-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 a64694287d2c..1e302775cc23 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);