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 9FBB8C636CD for ; Fri, 10 Feb 2023 17:38:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232659AbjBJRh7 (ORCPT ); Fri, 10 Feb 2023 12:37:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44716 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232386AbjBJRh6 (ORCPT ); Fri, 10 Feb 2023 12:37:58 -0500 Received: from smtp-8fab.mail.infomaniak.ch (smtp-8fab.mail.infomaniak.ch [IPv6:2001:1600:3:17::8fab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D00E435247 for ; Fri, 10 Feb 2023 09:37:56 -0800 (PST) Received: from smtp-3-0000.mail.infomaniak.ch (unknown [10.4.36.107]) by smtp-2-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4PD1Cl0fmxzMrH7D; Fri, 10 Feb 2023 18:37:55 +0100 (CET) Received: from unknown by smtp-3-0000.mail.infomaniak.ch (Postfix) with ESMTPA id 4PD1Ck2scyzlgQ; Fri, 10 Feb 2023 18:37:54 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=digikod.net; s=20191114; t=1676050674; bh=ca5OzA0HqP2+e+kn7erjO7uqKO+YjgTZQMieOxfqNL0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=1FzvKLlNUk2sO+lY2Wh7SQAcyAn3cv6TOqWm0pdocbnVNA+z4yN8+5gUHYCHAGn4J pJaVyefmBOUCqxvocRaUS4/mWzSXtan0xMeXpqldCR3Q3Ib/oJYWKDVjCz648BvYXV 2R4NOz+1HI5lqbX4XVw/7VJcMEor5fQThSZqJKY8= Message-ID: Date: Fri, 10 Feb 2023 18:37:53 +0100 MIME-Version: 1.0 User-Agent: Subject: Re: [PATCH v9 05/12] landlock: Move and rename umask_layers() and init_layer_masks() Content-Language: en-US To: Konstantin Meskhidze Cc: willemdebruijn.kernel@gmail.com, gnoack3000@gmail.com, linux-security-module@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, yusongping@huawei.com, artem.kuzin@huawei.com References: <20230116085818.165539-1-konstantin.meskhidze@huawei.com> <20230116085818.165539-6-konstantin.meskhidze@huawei.com> From: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= In-Reply-To: <20230116085818.165539-6-konstantin.meskhidze@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Infomaniak-Routing: alpha Precedence: bulk List-ID: On 16/01/2023 09:58, Konstantin Meskhidze wrote: > This patch renames and moves unmask_layers() and init_layer_masks() > helpers to ruleset.c to share them with Landlock network implementation > in following commits. > > Signed-off-by: Konstantin Meskhidze > --- > > Changes since v8: > * Refactors commit message. > * Adds "landlock_" prefix for moved helpers. > > Changes since v7: > * Refactors commit message. > > Changes since v6: > * Moves get_handled_accesses() helper from ruleset.c back to fs.c, > cause it's not used in coming network commits. > > Changes since v5: > * Splits commit. > * Moves init_layer_masks() and get_handled_accesses() helpers > to ruleset.c and makes then non-static. > * Formats code with clang-format-14. > > --- [...] > diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c > index 3e1cffda128e..22590cac3d56 100644 > --- a/security/landlock/ruleset.c > +++ b/security/landlock/ruleset.c > @@ -572,3 +572,101 @@ landlock_find_rule(const struct landlock_ruleset *const ruleset, > } > return NULL; > } > + > +/* > + * @layer_masks is read and may be updated according to the access request and > + * the matching rule. > + * > + * 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]) > +{ > + size_t layer_level; > + > + if (!access_request || !layer_masks) > + return true; > + if (!rule) > + return false; > + > + /* > + * An access is granted if, for each policy layer, at least one rule > + * encountered on the pathwalk grants the requested access, > + * regardless of its position in the layer stack. We must then check > + * the remaining layers for each inode, from the first added layer to > + * the last one. When there is multiple requested accesses, for each > + * policy layer, the full set of requested accesses may not be granted > + * by only one rule, but by the union (binary OR) of multiple rules. > + * E.g. /a/b + /a => /a/b > + */ > + for (layer_level = 0; layer_level < rule->num_layers; layer_level++) { > + const struct landlock_layer *const layer = > + &rule->layers[layer_level]; > + const layer_mask_t layer_bit = BIT_ULL(layer->level - 1); > + const unsigned long access_req = access_request; > + unsigned long access_bit; > + bool is_empty; > + > + /* > + * Records in @layer_masks which layer grants access to each > + * requested access. > + */ > + is_empty = true; > + for_each_set_bit(access_bit, &access_req, > + ARRAY_SIZE(*layer_masks)) { > + if (layer->access & BIT_ULL(access_bit)) > + (*layer_masks)[access_bit] &= ~layer_bit; > + is_empty = is_empty && !(*layer_masks)[access_bit]; > + } > + if (is_empty) > + return true; > + } > + return false; > +} > + > +/* Please keep the original "/**" > + * init_layer_masks - Initialize layer masks from an access request > + * > + * Populates @layer_masks such that for each access right in @access_request, > + * the bits for all the layers are set where this access right is handled. > + * > + * @domain: The domain that defines the current restrictions. > + * @access_request: The requested access rights to check. > + * @layer_masks: The layer masks to populate. > + * > + * Returns: An access mask where each access right bit is set which is handled > + * in any of the active layers in @domain. > + */