read_skill_md and read_skill_reference walk all skill files via
_iter_skill_files and return the first match by slug, regardless
of owner. In a multi-user deployment where two users have skills
with the same slug under different categories, a caller scoped
to owner='alice' can read Bob's skill content.
This is the same cross-tenant leak class as the update_skill /
delete_skill fix (PR #755, merged), but on the read path.
Changes:
- read_skill_md / read_skill_reference accept owner= param (default
None = match ownerless only, matching the write-path convention).
- 7 callers updated: tool_implementations.py (view, view_ref, patch),
builtin_actions.py (test_skills), skills_routes.py (audit, source,
test routes).
- Tests: read scoping (alice reads hers, not bob's), positive update
scoping (alice can mutate her own), ownerless-match default.
SkillsManager.update_skill walks every SKILL.md on disk and matches by
slug only; the 'owner' key in its scalar_keys whitelist meant a caller
could pass updates={'owner': 'attacker', 'description': 'pwned'} and the
first matching file on disk got silently re-owned. Two users with the
same slug under different category directories (which is supported by
the on-disk layout <category>/<name>/SKILL.md) could each stomp the
other's skill via the manage_skills tool or the in-process callers in
tool_implementations.py (edit, patch, publish, delete).
update_skill and delete_skill now require the caller's owner and only
match a file whose parsed owner field matches. The default of None
means 'no scope' and only matches ownerless skills, so an unsafe call
without an explicit owner is now a no-op. 'owner' is also removed from
scalar_keys so the updates dict cannot be used to reassign ownership
even when the manager is called from an in-process path that didn't
supply the owner argument.
The in-process callers in tool_implementations.py are updated to pass
owner=owner (which was already in scope at every call site) so the
HTTP and agent paths both go through the scoped check. The HTTP route
at routes/skills_routes.py:1499 was already owner-scoped via
sm.load(owner=user); the fix brings the in-process path up to the
same standard.
