open-swe/tests/test_repo_binding_isolation.py
Adam Moussa e4bee74c53
fix: bind sandbox and token caches to repo to prevent thread-id collision
A PR head-branch name is attacker-controllable and get_thread_id_from_branch
derives a thread_id from its first UUID with no repo binding (TID-COLLIDE-01).
The in-memory sandbox cache and the per-thread GitHub-token cache were keyed on
thread_id alone, and a cached sandbox was reused after only an echo-ping, so a
different repo's webhook could bind to another thread's sandbox or token.

Without changing the persistent thread-id scheme:
- Persist the bound repo (owner/name) in thread metadata on sandbox creation and
  refuse to reuse a sandbox whose bound repo does not match the current event
  (SandboxRepoMismatchError); the in-memory proxy also carries the binding.
- Bind the GitHub-token cache entries to their repo and evict on a cross-repo
  read so a colliding thread_id cannot be served another repo's token.
- Thread repo through the reviewer and the webhook token resolvers.
2026-06-29 11:37:26 -04:00

124 lines
4.6 KiB
Python

"""Repo-binding isolation for the sandbox and GitHub-token caches.
Covers TID-COLLIDE-01: a second repo presenting a colliding thread_id must not
reuse the first repo's in-process sandbox or cached GitHub token.
"""
from __future__ import annotations
from datetime import UTC, datetime, timedelta
from typing import Any
import pytest
from agent import server
from agent.utils import github_token
@pytest.fixture(autouse=True)
def _clear_caches() -> None:
github_token._GITHUB_TOKEN_CACHE.clear()
server.SANDBOX_BACKENDS.clear()
# --- token cache repo binding ------------------------------------------------
def test_cached_token_not_reused_across_repos() -> None:
"""A token bound to repo A is refused for a colliding thread_id from repo B."""
future = (datetime.now(UTC) + timedelta(hours=1)).isoformat()
github_token.cache_github_token_for_thread(
"tid", "ghp_repoA", expires_at=future, repo={"owner": "acme", "name": "alpha"}
)
# Same thread_id, different repo → must NOT serve repo A's token.
cfg_b = {"configurable": {"thread_id": "tid", "repo": {"owner": "evil", "name": "beta"}}}
assert github_token.get_github_token(cfg_b) is None
# And the poisoned entry is evicted.
assert "tid" not in github_token._GITHUB_TOKEN_CACHE
def test_cached_token_reused_for_same_repo() -> None:
future = (datetime.now(UTC) + timedelta(hours=1)).isoformat()
github_token.cache_github_token_for_thread(
"tid", "ghp_repoA", expires_at=future, repo={"owner": "acme", "name": "alpha"}
)
cfg_a = {"configurable": {"thread_id": "tid", "repo": {"owner": "acme", "name": "alpha"}}}
assert github_token.get_github_token(cfg_a) == "ghp_repoA"
def test_unbound_token_served_when_repo_unknown() -> None:
"""Legacy entries with no bound repo still resolve when no repo is supplied."""
github_token.cache_github_token_for_thread("tid", "ghp_legacy")
assert github_token.get_github_token({"configurable": {"thread_id": "tid"}}) == "ghp_legacy"
def test_repo_cache_key_normalizes() -> None:
assert github_token.repo_cache_key({"owner": "o", "name": "r"}) == "o/r"
assert github_token.repo_cache_key("o/r") == "o/r"
assert github_token.repo_cache_key({"owner": "o"}) is None
assert github_token.repo_cache_key(None) is None
# --- sandbox repo binding ----------------------------------------------------
class _FakeBackend:
def __init__(self, sandbox_id: str) -> None:
self.id = sandbox_id
self.bound_repo: str | None = None
def execute(self, *_a: Any, **_k: Any) -> Any: # pragma: no cover - must not run
raise AssertionError("colliding-repo sandbox must not be pinged/reused")
@pytest.mark.asyncio
async def test_ensure_sandbox_refuses_colliding_repo(monkeypatch: pytest.MonkeyPatch) -> None:
async def fake_sandbox_id(_tid: str) -> str:
return "sb-A"
async def fake_bound_repo(_tid: str) -> str:
return "acme/alpha"
monkeypatch.setattr(server, "get_sandbox_id_from_metadata", fake_sandbox_id)
monkeypatch.setattr(server, "get_bound_repo_from_metadata", fake_bound_repo)
backend = _FakeBackend("sb-A")
backend.bound_repo = "acme/alpha"
server.SANDBOX_BACKENDS["tid"] = backend # type: ignore[assignment]
with pytest.raises(server.SandboxRepoMismatchError):
await server.ensure_sandbox_for_thread("tid", repo={"owner": "evil", "name": "beta"})
@pytest.mark.asyncio
async def test_ensure_sandbox_allows_matching_repo(monkeypatch: pytest.MonkeyPatch) -> None:
async def fake_sandbox_id(_tid: str) -> str:
return "sb-A"
async def fake_bound_repo(_tid: str) -> str:
return "acme/alpha"
calls: dict[str, int] = {"git": 0}
backend = _FakeBackend("sb-A")
backend.bound_repo = "acme/alpha"
async def fake_check(b: Any, *_a: Any, **_k: Any) -> Any:
return b
async def fake_refresh(b: Any, *_a: Any, **_k: Any) -> Any:
return b
async def fake_git(_b: Any) -> None:
calls["git"] += 1
monkeypatch.setattr(server, "get_sandbox_id_from_metadata", fake_sandbox_id)
monkeypatch.setattr(server, "get_bound_repo_from_metadata", fake_bound_repo)
monkeypatch.setattr(server, "check_or_recreate_sandbox", fake_check)
monkeypatch.setattr(server, "_refresh_github_proxy_or_recreate", fake_refresh)
monkeypatch.setattr(server, "set_sandbox_backend", lambda _tid, b, **_k: b)
monkeypatch.setattr(server, "_configure_git_identity", fake_git)
server.SANDBOX_BACKENDS["tid"] = backend # type: ignore[assignment]
result = await server.ensure_sandbox_for_thread("tid", repo={"owner": "acme", "name": "alpha"})
assert result is backend
assert calls["git"] == 1