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authorKonstantin Meskhidze <konstantin.meskhidze@huawei.com>2023-10-26 09:47:43 +0800
committerMickaël Salaün <mic@digikod.net>2023-10-26 21:07:12 +0200
commit6146b6141770206792d0e1155794cc48697c7985 (patch)
tree019e923c6287b21900b3de0f802cc02506b180ad
parenta4ac404b3032562ed6a34232b5266d0f446dd799 (diff)
landlock: Refactor merge/inherit_ruleset helpers
Refactor merge_ruleset() and inherit_ruleset() functions to support new rule types. Add merge_tree() and inherit_tree() helpers. They use a specific ruleset's red-black tree according to a key type argument. Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> Link: https://lore.kernel.org/r/20231026014751.414649-5-konstantin.meskhidze@huawei.com Signed-off-by: Mickaël Salaün <mic@digikod.net>
-rw-r--r--security/landlock/ruleset.c116
1 files changed, 74 insertions, 42 deletions
diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c
index 3553632e76d9..cf88754a3f30 100644
--- a/security/landlock/ruleset.c
+++ b/security/landlock/ruleset.c
@@ -300,36 +300,22 @@ static void put_hierarchy(struct landlock_hierarchy *hierarchy)
}
}
-static int merge_ruleset(struct landlock_ruleset *const dst,
- struct landlock_ruleset *const src)
+static int merge_tree(struct landlock_ruleset *const dst,
+ struct landlock_ruleset *const src,
+ const enum landlock_key_type key_type)
{
struct landlock_rule *walker_rule, *next_rule;
struct rb_root *src_root;
int err = 0;
might_sleep();
- /* Should already be checked by landlock_merge_ruleset() */
- if (WARN_ON_ONCE(!src))
- return 0;
- /* Only merge into a domain. */
- if (WARN_ON_ONCE(!dst || !dst->hierarchy))
- return -EINVAL;
+ lockdep_assert_held(&dst->lock);
+ lockdep_assert_held(&src->lock);
- src_root = get_root(src, LANDLOCK_KEY_INODE);
+ src_root = get_root(src, key_type);
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);
-
- /* Stacks the new layer. */
- if (WARN_ON_ONCE(src->num_layers != 1 || dst->num_layers < 1)) {
- err = -EINVAL;
- goto out_unlock;
- }
- 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,
node) {
@@ -338,23 +324,52 @@ static int merge_ruleset(struct landlock_ruleset *const dst,
} };
const struct landlock_id id = {
.key = walker_rule->key,
- .type = LANDLOCK_KEY_INODE,
+ .type = key_type,
};
- if (WARN_ON_ONCE(walker_rule->num_layers != 1)) {
- err = -EINVAL;
- goto out_unlock;
- }
- if (WARN_ON_ONCE(walker_rule->layers[0].level != 0)) {
- err = -EINVAL;
- goto out_unlock;
- }
+ if (WARN_ON_ONCE(walker_rule->num_layers != 1))
+ return -EINVAL;
+
+ if (WARN_ON_ONCE(walker_rule->layers[0].level != 0))
+ return -EINVAL;
+
layers[0].access = walker_rule->layers[0].access;
err = insert_rule(dst, id, &layers, ARRAY_SIZE(layers));
if (err)
- goto out_unlock;
+ return err;
}
+ return err;
+}
+
+static int merge_ruleset(struct landlock_ruleset *const dst,
+ struct landlock_ruleset *const src)
+{
+ int err = 0;
+
+ might_sleep();
+ /* Should already be checked by landlock_merge_ruleset() */
+ if (WARN_ON_ONCE(!src))
+ return 0;
+ /* Only merge into a domain. */
+ if (WARN_ON_ONCE(!dst || !dst->hierarchy))
+ return -EINVAL;
+
+ /* Locks @dst first because we are its only owner. */
+ mutex_lock(&dst->lock);
+ mutex_lock_nested(&src->lock, SINGLE_DEPTH_NESTING);
+
+ /* Stacks the new layer. */
+ if (WARN_ON_ONCE(src->num_layers != 1 || dst->num_layers < 1)) {
+ err = -EINVAL;
+ goto out_unlock;
+ }
+ dst->access_masks[dst->num_layers - 1] = src->access_masks[0];
+
+ /* Merges the @src inode tree. */
+ err = merge_tree(dst, src, LANDLOCK_KEY_INODE);
+ if (err)
+ goto out_unlock;
out_unlock:
mutex_unlock(&src->lock);
@@ -362,38 +377,55 @@ out_unlock:
return err;
}
-static int inherit_ruleset(struct landlock_ruleset *const parent,
- struct landlock_ruleset *const child)
+static int inherit_tree(struct landlock_ruleset *const parent,
+ struct landlock_ruleset *const child,
+ const enum landlock_key_type key_type)
{
struct landlock_rule *walker_rule, *next_rule;
struct rb_root *parent_root;
int err = 0;
might_sleep();
- if (!parent)
- return 0;
+ lockdep_assert_held(&parent->lock);
+ lockdep_assert_held(&child->lock);
- parent_root = get_root(parent, LANDLOCK_KEY_INODE);
+ parent_root = get_root(parent, key_type);
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. */
+ /* Copies the @parent inode or network tree. */
rbtree_postorder_for_each_entry_safe(walker_rule, next_rule,
parent_root, node) {
const struct landlock_id id = {
.key = walker_rule->key,
- .type = LANDLOCK_KEY_INODE,
+ .type = key_type,
};
err = insert_rule(child, id, &walker_rule->layers,
walker_rule->num_layers);
if (err)
- goto out_unlock;
+ return err;
}
+ return err;
+}
+
+static int inherit_ruleset(struct landlock_ruleset *const parent,
+ struct landlock_ruleset *const child)
+{
+ int err = 0;
+
+ might_sleep();
+ if (!parent)
+ return 0;
+
+ /* Locks @child first because we are its only owner. */
+ mutex_lock(&child->lock);
+ mutex_lock_nested(&parent->lock, SINGLE_DEPTH_NESTING);
+
+ /* Copies the @parent inode tree. */
+ err = inherit_tree(parent, child, LANDLOCK_KEY_INODE);
+ if (err)
+ goto out_unlock;
if (WARN_ON_ONCE(child->num_layers <= parent->num_layers)) {
err = -EINVAL;