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 E2AE6C433FE for ; Thu, 17 Nov 2022 18:41:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240619AbiKQSlf (ORCPT ); Thu, 17 Nov 2022 13:41:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240621AbiKQSlX (ORCPT ); Thu, 17 Nov 2022 13:41:23 -0500 X-Greylist: delayed 101706 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 17 Nov 2022 10:41:07 PST Received: from smtp-bc0a.mail.infomaniak.ch (smtp-bc0a.mail.infomaniak.ch [45.157.188.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1AD7E7FF33 for ; Thu, 17 Nov 2022 10:41:06 -0800 (PST) Received: from smtp-3-0001.mail.infomaniak.ch (unknown [10.4.36.108]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4NCpdn59QZzMqMpv; Thu, 17 Nov 2022 19:41:01 +0100 (CET) Received: from ns3096276.ip-94-23-54.eu (unknown [23.97.221.149]) by smtp-3-0001.mail.infomaniak.ch (Postfix) with ESMTPA id 4NCpdm6ym8zMppYx; Thu, 17 Nov 2022 19:41:00 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=digikod.net; s=20191114; t=1668710461; bh=vVRpFKzQtqfkyjaOnej22IcnUL9qZNir+4epNtYIy1s=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=oYMvzfLhEb3zhXGq4LwXet6GehJYbWRnXc4rwsmyl6NqqGF06G9kEEVjnDq7N5Gk5 5fu9pPPGoblhVtpU0gec8jb1Cu5esyMErYDdC9EnTmajOctltwamEQnJ521/pzrnaM lb+NuyVdWy0lP4Tz3JPau1iqICFtpeOiNE6KCa4k= Message-ID: <94ed4212-c093-9c5c-089f-e9e4097e5bd6@digikod.net> Date: Thu, 17 Nov 2022 19:41:00 +0100 MIME-Version: 1.0 User-Agent: Subject: Re: [PATCH v8 01/12] landlock: Make ruleset's access masks more generic 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, artem.kuzin@huawei.com References: <20221021152644.155136-1-konstantin.meskhidze@huawei.com> <20221021152644.155136-2-konstantin.meskhidze@huawei.com> From: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= In-Reply-To: <20221021152644.155136-2-konstantin.meskhidze@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 21/10/2022 17:26, Konstantin Meskhidze wrote: > To support network type rules, this modification renames ruleset's > access masks and modifies it's type to access_masks_t. This patch > adds filesystem helper functions to add and get filesystem mask. > > Signed-off-by: Konstantin Meskhidze > --- > > Changes since v7: > * Refactors commit message. > > Changes since v6: > * Adds a new access_masks_t for struct ruleset. > * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() > because it OR values. > * Makes landlock_add_fs_access_mask() more resilient incorrect values. > * Refactors landlock_get_fs_access_mask(). > > Changes since v6: > * Adds a new access_masks_t for struct ruleset. > * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() > because it OR values. > * Makes landlock_add_fs_access_mask() more resilient incorrect values. > * Refactors landlock_get_fs_access_mask(). > > Changes since v5: > * Changes access_mask_t to u32. > * Formats code with clang-format-14. > > Changes since v4: > * Deletes struct landlock_access_mask. > > Changes since v3: > * Splits commit. > * Adds get_mask, set_mask helpers for filesystem. > * Adds new struct landlock_access_mask. > > --- > security/landlock/fs.c | 10 +++++----- > security/landlock/limits.h | 1 + > security/landlock/ruleset.c | 17 +++++++++-------- > security/landlock/ruleset.h | 35 +++++++++++++++++++++++++++++++---- > security/landlock/syscalls.c | 7 ++++--- > 5 files changed, 50 insertions(+), 20 deletions(-) > > diff --git a/security/landlock/fs.c b/security/landlock/fs.c > index adcea0fe7e68..0d57c6479d29 100644 > --- a/security/landlock/fs.c > +++ b/security/landlock/fs.c > @@ -178,9 +178,9 @@ 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->fs_access_masks[0] | ACCESS_INITIALLY_DENIED); > + access_rights |= LANDLOCK_MASK_ACCESS_FS & > + ~(landlock_get_fs_access_mask(ruleset, 0) | > + ACCESS_INITIALLY_DENIED); > object = get_inode_object(d_backing_inode(path->dentry)); > if (IS_ERR(object)) > return PTR_ERR(object); > @@ -294,7 +294,7 @@ get_handled_accesses(const struct landlock_ruleset *const domain) > size_t layer_level; > > for (layer_level = 0; layer_level < domain->num_layers; layer_level++) > - access_dom |= domain->fs_access_masks[layer_level]; > + access_dom |= landlock_get_fs_access_mask(domain, layer_level); > return access_dom & LANDLOCK_MASK_ACCESS_FS; You can remove `& LANDLOCK_MASK_ACCESS_FS` here because it is now part of landlock_get_fs_access_mask(). > } > > @@ -336,7 +336,7 @@ init_layer_masks(const struct landlock_ruleset *const domain, > * access rights. > */ > if (BIT_ULL(access_bit) & > - (domain->fs_access_masks[layer_level] | > + (landlock_get_fs_access_mask(domain, layer_level) | > ACCESS_INITIALLY_DENIED)) { > (*layer_masks)[access_bit] |= > BIT_ULL(layer_level); > diff --git a/security/landlock/limits.h b/security/landlock/limits.h > index 82288f0e9e5e..bafb3b8dc677 100644 > --- a/security/landlock/limits.h > +++ b/security/landlock/limits.h > @@ -21,6 +21,7 @@ > #define LANDLOCK_LAST_ACCESS_FS LANDLOCK_ACCESS_FS_TRUNCATE > #define LANDLOCK_MASK_ACCESS_FS ((LANDLOCK_LAST_ACCESS_FS << 1) - 1) > #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) > +#define LANDLOCK_SHIFT_ACCESS_FS 0 > > /* clang-format on */ > > diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c > index 996484f98bfd..1f3188b4e313 100644 > --- a/security/landlock/ruleset.c > +++ b/security/landlock/ruleset.c > @@ -29,7 +29,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) > struct landlock_ruleset *new_ruleset; > > new_ruleset = > - kzalloc(struct_size(new_ruleset, fs_access_masks, num_layers), > + kzalloc(struct_size(new_ruleset, access_masks, num_layers), > GFP_KERNEL_ACCOUNT); > if (!new_ruleset) > return ERR_PTR(-ENOMEM); > @@ -40,7 +40,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) > /* > * hierarchy = NULL > * num_rules = 0 > - * fs_access_masks[] = 0 > + * access_masks[] = 0 > */ > return new_ruleset; > } > @@ -55,7 +55,7 @@ landlock_create_ruleset(const access_mask_t fs_access_mask) > return ERR_PTR(-ENOMSG); > new_ruleset = create_ruleset(1); > if (!IS_ERR(new_ruleset)) > - new_ruleset->fs_access_masks[0] = fs_access_mask; > + landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); > return new_ruleset; > } > > @@ -117,11 +117,12 @@ static void build_check_ruleset(void) > .num_rules = ~0, > .num_layers = ~0, > }; > - typeof(ruleset.fs_access_masks[0]) fs_access_mask = ~0; > + typeof(ruleset.access_masks[0]) access_masks = ~0; > > BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); > BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); > - BUILD_BUG_ON(fs_access_mask < LANDLOCK_MASK_ACCESS_FS); > + BUILD_BUG_ON(access_masks < > + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); > } > > /** > @@ -281,7 +282,7 @@ static int merge_ruleset(struct landlock_ruleset *const dst, > err = -EINVAL; > goto out_unlock; > } > - dst->fs_access_masks[dst->num_layers - 1] = src->fs_access_masks[0]; > + dst->access_masks[dst->num_layers - 1] = src->access_masks[0]; > > /* Merges the @src tree. */ > rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, &src->root, > @@ -340,8 +341,8 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, > goto out_unlock; > } > /* Copies the parent layer stack and leaves a space for the new layer. */ > - memcpy(child->fs_access_masks, parent->fs_access_masks, > - flex_array_size(parent, fs_access_masks, parent->num_layers)); > + memcpy(child->access_masks, parent->access_masks, > + flex_array_size(parent, access_masks, parent->num_layers)); > > if (WARN_ON_ONCE(!parent->hierarchy)) { > err = -EINVAL; > diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h > index d43231b783e4..f2ad932d396c 100644 > --- a/security/landlock/ruleset.h > +++ b/security/landlock/ruleset.h > @@ -25,6 +25,11 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); > /* Makes sure for_each_set_bit() and for_each_clear_bit() calls are OK. */ > static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); > > +/* Ruleset access masks. */ > +typedef u16 access_masks_t; > +/* Makes sure all ruleset access rights can be stored. */ > +static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); > + > typedef u16 layer_mask_t; > /* Makes sure all layers can be checked. */ > static_assert(BITS_PER_TYPE(layer_mask_t) >= LANDLOCK_MAX_NUM_LAYERS); > @@ -110,7 +115,7 @@ struct landlock_ruleset { > * section. This is only used by > * landlock_put_ruleset_deferred() when @usage reaches zero. > * The fields @lock, @usage, @num_rules, @num_layers and > - * @fs_access_masks are then unused. > + * @access_masks are then unused. > */ > struct work_struct work_free; > struct { > @@ -137,7 +142,7 @@ struct landlock_ruleset { > */ > u32 num_layers; > /** > - * @fs_access_masks: Contains the subset of filesystem > + * @access_masks: Contains the subset of filesystem > * actions that are restricted by a ruleset. A domain > * saves all layers of merged rulesets in a stack > * (FAM), starting from the first layer to the last > @@ -148,13 +153,13 @@ struct landlock_ruleset { > * layers are set once and never changed for the > * lifetime of the ruleset. > */ > - access_mask_t fs_access_masks[]; > + access_masks_t access_masks[]; > }; > }; > }; > > struct landlock_ruleset * > -landlock_create_ruleset(const access_mask_t fs_access_mask); > +landlock_create_ruleset(const access_mask_t access_mask); > > void landlock_put_ruleset(struct landlock_ruleset *const ruleset); > void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); > @@ -177,4 +182,26 @@ static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) > refcount_inc(&ruleset->usage); > } > > +static inline void > +landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, > + const access_mask_t fs_access_mask, > + const u16 layer_level) > +{ > + access_mask_t fs_mask = fs_access_mask & LANDLOCK_MASK_ACCESS_FS; > + > + /* Should already be checked in sys_landlock_create_ruleset(). */ > + WARN_ON_ONCE(fs_access_mask != fs_mask); > + // TODO: Add tests to check "|=" and not "=" This todo should be done and removed. No more todos must remain. > + ruleset->access_masks[layer_level] |= > + (fs_mask << LANDLOCK_SHIFT_ACCESS_FS); > +} > + > +static inline access_mask_t > +landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, > + const u16 layer_level) > +{ > + return (ruleset->access_masks[layer_level] >> > + LANDLOCK_SHIFT_ACCESS_FS) & > + LANDLOCK_MASK_ACCESS_FS; > +} > #endif /* _SECURITY_LANDLOCK_RULESET_H */ > diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c > index 245cc650a4dc..71aca7f990bc 100644 > --- a/security/landlock/syscalls.c > +++ b/security/landlock/syscalls.c > @@ -346,10 +346,11 @@ SYSCALL_DEFINE4(landlock_add_rule, const int, ruleset_fd, > } > /* > * Checks that allowed_access matches the @ruleset constraints > - * (ruleset->fs_access_masks[0] is automatically upgraded to 64-bits). > + * (ruleset->access_masks[0] is automatically upgraded to 64-bits). > */ > - if ((path_beneath_attr.allowed_access | ruleset->fs_access_masks[0]) != > - ruleset->fs_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 > I'll send a patch to be applied after this one.