}
@@ -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 "="
