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 296D3C54EE9 for ; Tue, 6 Sep 2022 08:09:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233682AbiIFIJG (ORCPT ); Tue, 6 Sep 2022 04:09:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48716 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239035AbiIFIIu (ORCPT ); Tue, 6 Sep 2022 04:08:50 -0400 Received: from smtp-8fac.mail.infomaniak.ch (smtp-8fac.mail.infomaniak.ch [IPv6:2001:1600:4:17::8fac]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA9925E33C for ; Tue, 6 Sep 2022 01:08:48 -0700 (PDT) Received: from smtp-2-0001.mail.infomaniak.ch (unknown [10.5.36.108]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4MMJ1V7499zMpvC1; Tue, 6 Sep 2022 10:08:46 +0200 (CEST) Received: from ns3096276.ip-94-23-54.eu (unknown [23.97.221.149]) by smtp-2-0001.mail.infomaniak.ch (Postfix) with ESMTPA id 4MMJ1V1jCdzMppMk; Tue, 6 Sep 2022 10:08:46 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=digikod.net; s=20191114; t=1662451726; bh=SV2HdLdmR7X33EKl1Bu74hIg/BGfH+6BscyQdmft/V8=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=rrdmWGSrdMwgGRTyDjU0BO4dshIxuSS6T/WxzlKFstSOq7OzX4wpnQt3kL/U5uobV X83wnaeOoQr9ZcOGBuGrpdHVHIfTFxh3zMc6z+671S1VPHLbxVyLDcLn+O9p+8C7CE Nqm7h12bcQ7NUdXQiz9Bj13x/5DAyRh8rCZ84H+g= Message-ID: <9cf95acb-14a0-0900-c5af-c910de80e289@digikod.net> Date: Tue, 6 Sep 2022 10:08:45 +0200 MIME-Version: 1.0 User-Agent: Subject: Re: [PATCH v7 08/18] landlock: add network rules support 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, hukeping@huawei.com, anton.sirazetdinov@huawei.com References: <20220829170401.834298-1-konstantin.meskhidze@huawei.com> <20220829170401.834298-9-konstantin.meskhidze@huawei.com> From: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= In-Reply-To: <20220829170401.834298-9-konstantin.meskhidze@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On 29/08/2022 19:03, Konstantin Meskhidze wrote: > This commit adds network rules support in internal landlock functions > (presented in ruleset.c) and landlock_create_ruleset syscall. > > Signed-off-by: Konstantin Meskhidze > --- > > Changes since v6: > * Renames landlock_set_net_access_mask() to landlock_add_net_access_mask() > because it OR values. > * Makes landlock_add_net_access_mask() more resilient incorrect values. > * Refactors landlock_get_net_access_mask(). > * Renames LANDLOCK_MASK_SHIFT_NET to LANDLOCK_SHIFT_ACCESS_NET and use > LANDLOCK_NUM_ACCESS_FS as value. > * Updates access_masks_t to u32 to support network access actions. > * Refactors landlock internal functions to support network actions with > landlock_key/key_type/id types. > > Changes since v5: > * Gets rid of partial revert from landlock_add_rule > syscall. > * Formats code with clang-format-14. > > Changes since v4: > * Refactors landlock_create_ruleset() - splits ruleset and > masks checks. > * Refactors landlock_create_ruleset() and landlock mask > setters/getters to support two rule types. > * Refactors landlock_add_rule syscall add_rule_path_beneath > function by factoring out get_ruleset_from_fd() and > landlock_put_ruleset(). > > Changes since v3: > * Splits commit. > * Adds network rule support for internal landlock functions. > * Adds set_mask and get_mask for network. > * Adds rb_root root_net_port. > > --- > security/landlock/limits.h | 6 +++++- > security/landlock/ruleset.c | 38 +++++++++++++++++++++++++++++---- > security/landlock/ruleset.h | 41 ++++++++++++++++++++++++++++++++++-- > security/landlock/syscalls.c | 8 ++++++- > 4 files changed, 85 insertions(+), 8 deletions(-) > > diff --git a/security/landlock/limits.h b/security/landlock/limits.h > index bafb3b8dc677..8a1a6463c64e 100644 > --- a/security/landlock/limits.h > +++ b/security/landlock/limits.h > @@ -23,6 +23,10 @@ > #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) > #define LANDLOCK_SHIFT_ACCESS_FS 0 > > -/* clang-format on */ > +#define LANDLOCK_LAST_ACCESS_NET LANDLOCK_ACCESS_NET_CONNECT_TCP > +#define LANDLOCK_MASK_ACCESS_NET ((LANDLOCK_LAST_ACCESS_NET << 1) - 1) > +#define LANDLOCK_NUM_ACCESS_NET __const_hweight64(LANDLOCK_MASK_ACCESS_NET) > +#define LANDLOCK_SHIFT_ACCESS_NET LANDLOCK_NUM_ACCESS_FS > > +/* clang-format on */ > #endif /* _SECURITY_LANDLOCK_LIMITS_H */ > diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c > index 84fcd8eb30d4..442f212039df 100644 > --- a/security/landlock/ruleset.c > +++ b/security/landlock/ruleset.c > @@ -36,6 +36,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) > refcount_set(&new_ruleset->usage, 1); > mutex_init(&new_ruleset->lock); > new_ruleset->root_inode = RB_ROOT; > + new_ruleset->root_net_port = RB_ROOT; > new_ruleset->num_layers = num_layers; > /* > * hierarchy = NULL > @@ -46,16 +47,21 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) > } > > struct landlock_ruleset * > -landlock_create_ruleset(const access_mask_t fs_access_mask) > +landlock_create_ruleset(const access_mask_t fs_access_mask, > + const access_mask_t net_access_mask) > { > struct landlock_ruleset *new_ruleset; > > /* Informs about useless ruleset. */ > - if (!fs_access_mask) > + if (!fs_access_mask && !net_access_mask) > return ERR_PTR(-ENOMSG); > new_ruleset = create_ruleset(1); > - if (!IS_ERR(new_ruleset)) > + if (IS_ERR(new_ruleset)) > + return new_ruleset; > + if (fs_access_mask) > landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); > + if (net_access_mask) > + landlock_add_net_access_mask(new_ruleset, net_access_mask, 0); > return new_ruleset; > } > > @@ -73,6 +79,8 @@ static inline bool is_object_pointer(const enum landlock_key_type key_type) > switch (key_type) { > case LANDLOCK_KEY_INODE: > return true; > + case LANDLOCK_KEY_NET_PORT: > + return false; > } > WARN_ON_ONCE(1); > return false; > @@ -126,6 +134,9 @@ static inline struct rb_root *get_root(struct landlock_ruleset *const ruleset, > case LANDLOCK_KEY_INODE: > root = &ruleset->root_inode; > break; > + case LANDLOCK_KEY_NET_PORT: > + root = &ruleset->root_net_port; > + break; > } > if (WARN_ON_ONCE(!root)) > return ERR_PTR(-EINVAL); > @@ -154,7 +165,9 @@ static void build_check_ruleset(void) > BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); > BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); > BUILD_BUG_ON(access_masks < > - (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); > + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS) + > + (LANDLOCK_MASK_ACCESS_NET > + << LANDLOCK_SHIFT_ACCESS_NET)); > } > > /** > @@ -367,6 +380,11 @@ static int merge_ruleset(struct landlock_ruleset *const dst, > if (err) > goto out_unlock; > > + /* Merges the @src network port tree. */ > + err = merge_tree(dst, src, LANDLOCK_KEY_NET_PORT); > + if (err) > + goto out_unlock; > + > out_unlock: > mutex_unlock(&src->lock); > mutex_unlock(&dst->lock); > @@ -419,6 +437,11 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, > if (err) > goto out_unlock; > > + /* Copies the @parent network port tree. */ > + err = inherit_tree(parent, child, LANDLOCK_KEY_NET_PORT); > + if (err) > + goto out_unlock; > + > if (WARN_ON_ONCE(child->num_layers <= parent->num_layers)) { > err = -EINVAL; > goto out_unlock; > @@ -451,6 +474,9 @@ static void free_ruleset(struct landlock_ruleset *const ruleset) > rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root_inode, > node) > free_rule(freeme, LANDLOCK_KEY_INODE); > + rbtree_postorder_for_each_entry_safe(freeme, next, > + &ruleset->root_net_port, node) > + free_rule(freeme, LANDLOCK_KEY_NET_PORT); > put_hierarchy(ruleset->hierarchy); > kfree(ruleset); > } > @@ -640,6 +666,10 @@ access_mask_t init_layer_masks(const struct landlock_ruleset *const domain, > get_access_mask = landlock_get_fs_access_mask; > num_access = LANDLOCK_NUM_ACCESS_FS; > break; > + case LANDLOCK_KEY_NET_PORT: > + get_access_mask = landlock_get_net_access_mask; > + num_access = LANDLOCK_NUM_ACCESS_NET; > + break; > default: > WARN_ON_ONCE(1); > return 0; > diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h > index 2083855bf42d..d456ee90b648 100644 > --- a/security/landlock/ruleset.h > +++ b/security/landlock/ruleset.h > @@ -26,7 +26,7 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); > static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); > > /* Ruleset access masks. */ > -typedef u16 access_masks_t; > +typedef u32 access_masks_t; > /* Makes sure all ruleset access rights can be stored. */ > static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); There is some fixes missing from my patch. > > @@ -66,6 +66,11 @@ enum landlock_key_type { > * keys. > */ > LANDLOCK_KEY_INODE = 1, #if IS_ENABLED(CONFIG_INET) > + /** > + * @LANDLOCK_KEY_NET_PORT: Type of &landlock_ruleset.root_net_port's > + * node keys. > + */ > + LANDLOCK_KEY_NET_PORT = 2, #endif /* IS_ENABLED(CONFIG_INET) */ And then all use of LANDLOCK_KEY_NET_PORT should be surrounded by the same check (but not directly in the net.c file). > }; > > /** > @@ -133,6 +138,12 @@ struct landlock_ruleset { > * reaches zero. > */ > struct rb_root root_inode; #if IS_ENABLED(CONFIG_INET) > + /** > + * @root_net_port: Root of a red-black tree containing object nodes > + * for network port. Once a ruleset is tied to a process (i.e. as a domain), > + * this tree is immutable until @usage reaches zero. > + */ There is some fixes missing from my patch. Please explain everything that you didn't take. > + struct rb_root root_net_port; #endif /* IS_ENABLED(CONFIG_INET) */ And then all use of root_net_port should be surrounded by the same check. I think it should be OK to keep all other remaining network references though (e.g. access_masks and the ). > /** > * @hierarchy: Enables hierarchy identification even when a parent > * domain vanishes. This is needed for the ptrace protection. > @@ -188,7 +199,8 @@ struct landlock_ruleset { > }; > > struct landlock_ruleset * > -landlock_create_ruleset(const access_mask_t access_mask); > +landlock_create_ruleset(const access_mask_t access_mask_fs, > + const access_mask_t access_mask_net); > > void landlock_put_ruleset(struct landlock_ruleset *const ruleset); > void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); > @@ -226,6 +238,21 @@ landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, > (fs_mask << LANDLOCK_SHIFT_ACCESS_FS); > } > > +/* A helper function to set a network mask. */ I already said that this comment is useless, and I removed it in my patch. Please take a closer look at reviews. > +static inline void > +landlock_add_net_access_mask(struct landlock_ruleset *const ruleset, > + const access_mask_t net_access_mask, > + const u16 layer_level) > +{ > + access_mask_t net_mask = net_access_mask & LANDLOCK_MASK_ACCESS_NET; > + > + /* Should already be checked in sys_landlock_create_ruleset(). */ > + WARN_ON_ONCE(net_access_mask != net_mask); > + // TODO: Add tests to check "|=" and not "=" > + ruleset->access_masks[layer_level] |= > + (net_mask << LANDLOCK_SHIFT_ACCESS_NET); > +} > + > /* A helper function to get a filesystem mask. */ > static inline access_mask_t > landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, > @@ -236,6 +263,16 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, > LANDLOCK_MASK_ACCESS_FS; > } > > +/* A helper function to get a network mask. */ > +static inline access_mask_t > +landlock_get_net_access_mask(const struct landlock_ruleset *const ruleset, > + const u16 layer_level) > +{ > + return (ruleset->access_masks[layer_level] >> > + LANDLOCK_SHIFT_ACCESS_NET) & > + LANDLOCK_MASK_ACCESS_NET; > +} > + This hunk doesn't match my patch. > bool unmask_layers(const struct landlock_rule *const rule, > const access_mask_t access_request, > layer_mask_t (*const layer_masks)[], > diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c > index ffd5805eddd9..641155f6f6f8 100644 > --- a/security/landlock/syscalls.c > +++ b/security/landlock/syscalls.c > @@ -189,8 +189,14 @@ SYSCALL_DEFINE3(landlock_create_ruleset, > LANDLOCK_MASK_ACCESS_FS) > return -EINVAL; > > + /* Checks network content (and 32-bits cast). */ > + if ((ruleset_attr.handled_access_net | LANDLOCK_MASK_ACCESS_NET) != > + LANDLOCK_MASK_ACCESS_NET) > + return -EINVAL; > + > /* Checks arguments and transforms to kernel struct. */ > - ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs); > + ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs, > + ruleset_attr.handled_access_net); > if (IS_ERR(ruleset)) > return PTR_ERR(ruleset); > > -- > 2.25.1 >