From: "Mickaël Salaün" <mic@digikod.net>
To: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
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
Subject: Re: [PATCH v9 05/12] landlock: Move and rename umask_layers() and init_layer_masks()
Date: Fri, 10 Feb 2023 18:37:53 +0100 [thread overview]
Message-ID: <dcb11989-fa8d-3966-77da-2ff5fab2ef32@digikod.net> (raw)
In-Reply-To: <20230116085818.165539-6-konstantin.meskhidze@huawei.com>
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 <konstantin.meskhidze@huawei.com>
> ---
>
> 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 <execute> + /a <read> => /a/b <execute + read>
> + */
> + 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.
> + */
next prev parent reply other threads:[~2023-02-10 17:38 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-16 8:58 [PATCH v9 00/12] Network support for Landlock Konstantin Meskhidze
2023-01-16 8:58 ` [PATCH v9 01/12] landlock: Make ruleset's access masks more generic Konstantin Meskhidze
2023-01-16 8:58 ` [PATCH v9 02/12] landlock: Allow filesystem layout changes for domains without such rule type Konstantin Meskhidze
2023-02-10 17:34 ` Mickaël Salaün
2023-02-14 8:51 ` Konstantin Meskhidze (A)
2023-02-14 12:07 ` Mickaël Salaün
2023-02-14 12:57 ` Konstantin Meskhidze (A)
2023-01-16 8:58 ` [PATCH v9 03/12] landlock: Refactor landlock_find_rule/insert_rule Konstantin Meskhidze
2023-02-10 17:36 ` Mickaël Salaün
2023-02-14 10:15 ` Konstantin Meskhidze (A)
2023-02-14 12:09 ` Mickaël Salaün
2023-02-14 13:28 ` Konstantin Meskhidze (A)
2023-01-16 8:58 ` [PATCH v9 04/12] landlock: Refactor merge/inherit_ruleset functions Konstantin Meskhidze
2023-01-16 8:58 ` [PATCH v9 05/12] landlock: Move and rename umask_layers() and init_layer_masks() Konstantin Meskhidze
2023-02-10 17:37 ` Mickaël Salaün [this message]
2023-02-14 10:15 ` Konstantin Meskhidze (A)
2023-01-16 8:58 ` [PATCH v9 06/12] landlock: Refactor _unmask_layers() and _init_layer_masks() Konstantin Meskhidze
2023-02-10 17:38 ` Mickaël Salaün
2023-02-14 10:16 ` Konstantin Meskhidze (A)
2023-02-21 18:07 ` Mickaël Salaün
2023-03-06 7:52 ` Konstantin Meskhidze (A)
2023-01-16 8:58 ` [PATCH v9 07/12] landlock: Refactor landlock_add_rule() syscall Konstantin Meskhidze
2023-02-10 17:38 ` Mickaël Salaün
2023-02-14 10:18 ` Konstantin Meskhidze (A)
2023-01-16 8:58 ` [PATCH v9 08/12] landlock: Add network rules and TCP hooks support Konstantin Meskhidze
2023-02-10 17:39 ` Mickaël Salaün
2023-02-14 10:19 ` Konstantin Meskhidze (A)
2023-03-13 9:33 ` Konstantin Meskhidze (A)
2023-03-14 12:13 ` Mickaël Salaün
2023-03-14 14:38 ` Konstantin Meskhidze (A)
2023-02-21 18:04 ` Mickaël Salaün
2023-03-06 10:18 ` Konstantin Meskhidze (A)
2023-01-16 8:58 ` [PATCH v9 09/12] selftests/landlock: Share enforce_ruleset() Konstantin Meskhidze
2023-01-16 8:58 ` [PATCH v9 10/12] selftests/landlock: Add 10 new test suites dedicated to network Konstantin Meskhidze
2023-02-10 17:40 ` Mickaël Salaün
2023-02-14 10:36 ` Konstantin Meskhidze (A)
2023-02-14 12:13 ` Mickaël Salaün
2023-02-14 13:28 ` Konstantin Meskhidze (A)
2023-02-21 18:05 ` Mickaël Salaün
2023-03-06 12:03 ` Konstantin Meskhidze (A)
2023-03-06 16:00 ` Mickaël Salaün
2023-03-06 18:13 ` Konstantin Meskhidze (A)
2023-01-16 8:58 ` [PATCH v9 11/12] samples/landlock: Add network demo Konstantin Meskhidze
2023-01-16 8:58 ` [PATCH v9 12/12] landlock: Document Landlock's network support Konstantin Meskhidze
2023-01-21 23:07 ` Günther Noack
2023-01-23 9:38 ` Konstantin Meskhidze (A)
2023-01-27 18:22 ` Mickaël Salaün
2023-01-30 10:03 ` Konstantin Meskhidze (A)
2023-02-21 16:16 ` Mickaël Salaün
2023-03-06 13:43 ` Konstantin Meskhidze (A)
2023-03-06 16:09 ` Mickaël Salaün
2023-03-06 17:55 ` Konstantin Meskhidze (A)
2023-01-30 12:26 ` Konstantin Meskhidze (A)
2023-02-23 22:17 ` [PATCH v9 00/12] Network support for Landlock Günther Noack
2023-03-06 7:45 ` Konstantin Meskhidze (A)
2023-03-13 17:16 ` Konstantin Meskhidze (A)
2023-03-14 13:28 ` Mickaël Salaün
2023-06-26 15:29 ` [PATCH v9 00/12] Network support for Landlock - allowed list of protocols Mickaël Salaün
2023-06-28 2:33 ` Jeff Xu
2023-06-28 19:03 ` Mickaël Salaün
2023-06-28 21:56 ` Jeff Xu
2023-06-28 8:44 ` Günther Noack
2023-06-28 17:03 ` Jeff Xu
2023-06-28 19:29 ` Mickaël Salaün
2023-06-29 3:18 ` Jeff Xu
2023-06-29 11:07 ` Mickaël Salaün
2023-06-30 4:18 ` Jeff Xu
2023-06-30 18:23 ` Mickaël Salaün
2023-07-05 15:00 ` Jeff Xu
2023-07-12 11:30 ` Mickaël Salaün
2023-07-13 13:20 ` Konstantin Meskhidze (A)
2023-07-13 14:52 ` Mickaël Salaün
2023-07-13 11:44 ` Konstantin Meskhidze (A)
2023-06-28 19:07 ` Mickaël Salaün
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