[RFC PATCH v4 01/15] landlock: access mask renaming
Mickaël Salaün
mic at digikod.net
Fri Apr 1 16:47:56 UTC 2022
On 09/03/2022 14:44, Konstantin Meskhidze wrote:
> Currently Landlock supports filesystem
> restrictions. To support network type rules,
> this modification extends and renames
> ruleset's access masks.
Please use 72 columns for all commit messages.
With vim: set tw=72
The code looks good but you'll have to rebase it on top of my
access_mask_t changes.
Next time you can rebase your changes on my landlock-wip branch at
https://git.kernel.org/pub/scm/linux/kernel/git/mic/linux.git
I'll update this branch regularly but it should not impact much your
changes.
>
> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze at huawei.com>
> ---
>
> Changes since v3:
> * Split commit.
>
> ---
> security/landlock/fs.c | 4 ++--
> security/landlock/ruleset.c | 18 +++++++++---------
> security/landlock/ruleset.h | 8 ++++----
> security/landlock/syscalls.c | 6 +++---
> 4 files changed, 18 insertions(+), 18 deletions(-)
>
> diff --git a/security/landlock/fs.c b/security/landlock/fs.c
> index 97b8e421f617..d727bdab7840 100644
> --- a/security/landlock/fs.c
> +++ b/security/landlock/fs.c
> @@ -163,7 +163,7 @@ 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_rights |= LANDLOCK_MASK_ACCESS_FS & ~ruleset->access_masks[0];
> object = get_inode_object(d_backing_inode(path->dentry));
> if (IS_ERR(object))
> return PTR_ERR(object);
> @@ -252,7 +252,7 @@ static int check_access_path(const struct landlock_ruleset *const domain,
> /* Saves all layers handling a subset of requested accesses. */
> layer_mask = 0;
> for (i = 0; i < domain->num_layers; i++) {
> - if (domain->fs_access_masks[i] & access_request)
> + if (domain->access_masks[i] & access_request)
> layer_mask |= BIT_ULL(i);
> }
> /* An access request not handled by the domain is allowed. */
> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c
> index ec72b9262bf3..78341a0538de 100644
> --- a/security/landlock/ruleset.c
> +++ b/security/landlock/ruleset.c
> @@ -28,7 +28,7 @@ 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,
> + new_ruleset = kzalloc(struct_size(new_ruleset, access_masks,
> num_layers), GFP_KERNEL_ACCOUNT);
> if (!new_ruleset)
> return ERR_PTR(-ENOMEM);
> @@ -39,21 +39,21 @@ 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;
> }
>
> -struct landlock_ruleset *landlock_create_ruleset(const u32 fs_access_mask)
> +struct landlock_ruleset *landlock_create_ruleset(const u32 access_mask)
> {
> struct landlock_ruleset *new_ruleset;
>
> /* Informs about useless ruleset. */
> - if (!fs_access_mask)
> + if (!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;
> + new_ruleset->access_masks[0] = access_mask;
> return new_ruleset;
> }
>
> @@ -116,7 +116,7 @@ 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]) fs_access_mask = ~0;
>
> BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES);
> BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS);
> @@ -279,7 +279,7 @@ 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,
> @@ -337,8 +337,8 @@ 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 2d3ed7ec5a0a..32d90ce72428 100644
> --- a/security/landlock/ruleset.h
> +++ b/security/landlock/ruleset.h
> @@ -97,7 +97,7 @@ 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 {
> @@ -124,7 +124,7 @@ 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
> @@ -135,12 +135,12 @@ struct landlock_ruleset {
> * layers are set once and never changed for the
> * lifetime of the ruleset.
> */
> - u16 fs_access_masks[];
> + u32 access_masks[];
Changing from u16 to u32 is not correct for this patch, but it would not
be visible with access_mask_t anyway.
> };
> };
> };
>
> -struct landlock_ruleset *landlock_create_ruleset(const u32 fs_access_mask);
> +struct landlock_ruleset *landlock_create_ruleset(const u32 access_mask);
>
> void landlock_put_ruleset(struct landlock_ruleset *const ruleset);
> void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset);
> diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c
> index 32396962f04d..f1d86311df7e 100644
> --- a/security/landlock/syscalls.c
> +++ b/security/landlock/syscalls.c
> @@ -341,10 +341,10 @@ SYSCALL_DEFINE4(landlock_add_rule,
> }
> /*
> * 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 | ruleset->access_masks[0]) !=
> + ruleset->access_masks[0]) {
> err = -EINVAL;
> goto out_put_ruleset;
> }
> --
> 2.25.1
>
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