return ERR_PTR(-ENOMEM);
refcount_set(&new_ruleset->usage, 1);
mutex_init(&new_ruleset->lock);
- new_ruleset->root = RB_ROOT;
+ new_ruleset->root_inode = RB_ROOT;
new_ruleset->num_layers = num_layers;
/*
* hierarchy = NULL
BUILD_BUG_ON(rule.num_layers < LANDLOCK_MAX_NUM_LAYERS);
}
+static bool is_object_pointer(const enum landlock_key_type key_type)
+{
+ switch (key_type) {
+ case LANDLOCK_KEY_INODE:
+ return true;
+
+ default:
+ WARN_ON_ONCE(1);
+ return false;
+ }
+}
+
static struct landlock_rule *
-create_rule(struct landlock_object *const object,
+create_rule(const struct landlock_id id,
const struct landlock_layer (*const layers)[], const u32 num_layers,
const struct landlock_layer *const new_layer)
{
if (!new_rule)
return ERR_PTR(-ENOMEM);
RB_CLEAR_NODE(&new_rule->node);
- landlock_get_object(object);
- new_rule->object = object;
+ if (is_object_pointer(id.type)) {
+ /* This should be catched by insert_rule(). */
+ WARN_ON_ONCE(!id.key.object);
+ landlock_get_object(id.key.object);
+ }
+
+ new_rule->key = id.key;
new_rule->num_layers = new_num_layers;
/* Copies the original layer stack. */
memcpy(new_rule->layers, layers,
return new_rule;
}
-static void free_rule(struct landlock_rule *const rule)
+static struct rb_root *get_root(struct landlock_ruleset *const ruleset,
+ const enum landlock_key_type key_type)
+{
+ switch (key_type) {
+ case LANDLOCK_KEY_INODE:
+ return &ruleset->root_inode;
+
+ default:
+ WARN_ON_ONCE(1);
+ return ERR_PTR(-EINVAL);
+ }
+}
+
+static void free_rule(struct landlock_rule *const rule,
+ const enum landlock_key_type key_type)
{
might_sleep();
if (!rule)
return;
- landlock_put_object(rule->object);
+ if (is_object_pointer(key_type))
+ landlock_put_object(rule->key.object);
kfree(rule);
}
* insert_rule - Create and insert a rule in a ruleset
*
* @ruleset: The ruleset to be updated.
- * @object: The object to build the new rule with. The underlying kernel
- * object must be held by the caller.
+ * @id: The ID to build the new rule with. The underlying kernel object, if
+ * any, must be held by the caller.
* @layers: One or multiple layers to be copied into the new rule.
* @num_layers: The number of @layers entries.
*
* access rights.
*/
static int insert_rule(struct landlock_ruleset *const ruleset,
- struct landlock_object *const object,
+ const struct landlock_id id,
const struct landlock_layer (*const layers)[],
- size_t num_layers)
+ const size_t num_layers)
{
struct rb_node **walker_node;
struct rb_node *parent_node = NULL;
struct landlock_rule *new_rule;
+ struct rb_root *root;
might_sleep();
lockdep_assert_held(&ruleset->lock);
- if (WARN_ON_ONCE(!object || !layers))
+ if (WARN_ON_ONCE(!layers))
+ return -ENOENT;
+
+ if (is_object_pointer(id.type) && WARN_ON_ONCE(!id.key.object))
return -ENOENT;
- walker_node = &(ruleset->root.rb_node);
+
+ root = get_root(ruleset, id.type);
+ if (IS_ERR(root))
+ return PTR_ERR(root);
+
+ walker_node = &root->rb_node;
while (*walker_node) {
struct landlock_rule *const this =
rb_entry(*walker_node, struct landlock_rule, node);
- if (this->object != object) {
+ if (this->key.data != id.key.data) {
parent_node = *walker_node;
- if (this->object < object)
+ if (this->key.data < id.key.data)
walker_node = &((*walker_node)->rb_right);
else
walker_node = &((*walker_node)->rb_left);
* Intersects access rights when it is a merge between a
* ruleset and a domain.
*/
- new_rule = create_rule(object, &this->layers, this->num_layers,
+ new_rule = create_rule(id, &this->layers, this->num_layers,
&(*layers)[0]);
if (IS_ERR(new_rule))
return PTR_ERR(new_rule);
- rb_replace_node(&this->node, &new_rule->node, &ruleset->root);
- free_rule(this);
+ rb_replace_node(&this->node, &new_rule->node, root);
+ free_rule(this, id.type);
return 0;
}
- /* There is no match for @object. */
+ /* There is no match for @id. */
build_check_ruleset();
if (ruleset->num_rules >= LANDLOCK_MAX_NUM_RULES)
return -E2BIG;
- new_rule = create_rule(object, layers, num_layers, NULL);
+ new_rule = create_rule(id, layers, num_layers, NULL);
if (IS_ERR(new_rule))
return PTR_ERR(new_rule);
rb_link_node(&new_rule->node, parent_node, walker_node);
- rb_insert_color(&new_rule->node, &ruleset->root);
+ rb_insert_color(&new_rule->node, root);
ruleset->num_rules++;
return 0;
}
/* @ruleset must be locked by the caller. */
int landlock_insert_rule(struct landlock_ruleset *const ruleset,
- struct landlock_object *const object,
+ const struct landlock_id id,
const access_mask_t access)
{
struct landlock_layer layers[] = { {
} };
build_check_layer();
- return insert_rule(ruleset, object, &layers, ARRAY_SIZE(layers));
+ return insert_rule(ruleset, id, &layers, ARRAY_SIZE(layers));
}
static inline void get_hierarchy(struct landlock_hierarchy *const hierarchy)
struct landlock_ruleset *const src)
{
struct landlock_rule *walker_rule, *next_rule;
+ struct rb_root *src_root;
int err = 0;
might_sleep();
if (WARN_ON_ONCE(!dst || !dst->hierarchy))
return -EINVAL;
+ src_root = get_root(src, LANDLOCK_KEY_INODE);
+ if (IS_ERR(src_root))
+ return PTR_ERR(src_root);
+
/* Locks @dst first because we are its only owner. */
mutex_lock(&dst->lock);
mutex_lock_nested(&src->lock, SINGLE_DEPTH_NESTING);
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,
+ rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, src_root,
node) {
struct landlock_layer layers[] = { {
.level = dst->num_layers,
} };
+ const struct landlock_id id = {
+ .key = walker_rule->key,
+ .type = LANDLOCK_KEY_INODE,
+ };
if (WARN_ON_ONCE(walker_rule->num_layers != 1)) {
err = -EINVAL;
goto out_unlock;
}
layers[0].access = walker_rule->layers[0].access;
- err = insert_rule(dst, walker_rule->object, &layers,
- ARRAY_SIZE(layers));
+
+ err = insert_rule(dst, id, &layers, ARRAY_SIZE(layers));
if (err)
goto out_unlock;
}
struct landlock_ruleset *const child)
{
struct landlock_rule *walker_rule, *next_rule;
+ struct rb_root *parent_root;
int err = 0;
might_sleep();
if (!parent)
return 0;
+ parent_root = get_root(parent, LANDLOCK_KEY_INODE);
+ if (IS_ERR(parent_root))
+ return PTR_ERR(parent_root);
+
/* Locks @child first because we are its only owner. */
mutex_lock(&child->lock);
mutex_lock_nested(&parent->lock, SINGLE_DEPTH_NESTING);
/* Copies the @parent tree. */
rbtree_postorder_for_each_entry_safe(walker_rule, next_rule,
- &parent->root, node) {
- err = insert_rule(child, walker_rule->object,
- &walker_rule->layers,
+ parent_root, node) {
+ const struct landlock_id id = {
+ .key = walker_rule->key,
+ .type = LANDLOCK_KEY_INODE,
+ };
+
+ err = insert_rule(child, id, &walker_rule->layers,
walker_rule->num_layers);
if (err)
goto out_unlock;
struct landlock_rule *freeme, *next;
might_sleep();
- rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root, node)
- free_rule(freeme);
+ rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root_inode,
+ node)
+ free_rule(freeme, LANDLOCK_KEY_INODE);
put_hierarchy(ruleset->hierarchy);
kfree(ruleset);
}
*/
const struct landlock_rule *
landlock_find_rule(const struct landlock_ruleset *const ruleset,
- const struct landlock_object *const object)
+ const struct landlock_id id)
{
+ const struct rb_root *root;
const struct rb_node *node;
- if (!object)
+ root = get_root((struct landlock_ruleset *)ruleset, id.type);
+ if (IS_ERR(root))
return NULL;
- node = ruleset->root.rb_node;
+ node = root->rb_node;
+
while (node) {
struct landlock_rule *this =
rb_entry(node, struct landlock_rule, node);
- if (this->object == object)
+ if (this->key.data == id.key.data)
return this;
- if (this->object < object)
+ if (this->key.data < id.key.data)
node = node->rb_right;
else
node = node->rb_left;
access_mask_t access;
};
+/**
+ * union landlock_key - Key of a ruleset's red-black tree
+ */
+union landlock_key {
+ /**
+ * @object: Pointer to identify a kernel object (e.g. an inode).
+ */
+ struct landlock_object *object;
+ /**
+ * @data: Raw data to identify an arbitrary 32-bit value
+ * (e.g. a TCP port).
+ */
+ uintptr_t data;
+};
+
+/**
+ * enum landlock_key_type - Type of &union landlock_key
+ */
+enum landlock_key_type {
+ /**
+ * @LANDLOCK_KEY_INODE: Type of &landlock_ruleset.root_inode's node
+ * keys.
+ */
+ LANDLOCK_KEY_INODE = 1,
+};
+
+/**
+ * struct landlock_id - Unique rule identifier for a ruleset
+ */
+struct landlock_id {
+ /**
+ * @key: Identifies either a kernel object (e.g. an inode) or
+ * a raw value (e.g. a TCP port).
+ */
+ union landlock_key key;
+ /**
+ * @type: Type of a landlock_ruleset's root tree.
+ */
+ const enum landlock_key_type type;
+};
+
/**
* struct landlock_rule - Access rights tied to an object
*/
*/
struct rb_node node;
/**
- * @object: Pointer to identify a kernel object (e.g. an inode). This
- * is used as a key for this ruleset element. This pointer is set once
- * and never modified. It always points to an allocated object because
- * each rule increments the refcount of its object.
+ * @key: A union to identify either a kernel object (e.g. an inode) or
+ * a raw data value (e.g. a network socket port). This is used as a key
+ * for this ruleset element. The pointer is set once and never
+ * modified. It always points to an allocated object because each rule
+ * increments the refcount of its object.
*/
- struct landlock_object *object;
+ union landlock_key key;
/**
* @num_layers: Number of entries in @layers.
*/
*/
struct landlock_ruleset {
/**
- * @root: Root of a red-black tree containing &struct landlock_rule
- * nodes. Once a ruleset is tied to a process (i.e. as a domain), this
- * tree is immutable until @usage reaches zero.
+ * @root_inode: Root of a red-black tree containing &struct
+ * landlock_rule nodes with inode object. Once a ruleset is tied to a
+ * process (i.e. as a domain), this tree is immutable until @usage
+ * reaches zero.
*/
- struct rb_root root;
+ struct rb_root root_inode;
/**
* @hierarchy: Enables hierarchy identification even when a parent
* domain vanishes. This is needed for the ptrace protection.
void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset);
int landlock_insert_rule(struct landlock_ruleset *const ruleset,
- struct landlock_object *const object,
+ const struct landlock_id id,
const access_mask_t access);
struct landlock_ruleset *
const struct landlock_rule *
landlock_find_rule(const struct landlock_ruleset *const ruleset,
- const struct landlock_object *const object);
+ const struct landlock_id id);
static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset)
{
projects / thirdparty / linux.git / commitdiff
