Files
pydn-ComfyUI-to-Python-Exte…/comfyui_to_python/node_runtime.py
T
Peyton DeNiro 603fabdf32 harden import path resolution: full importlib isolation (Approach B)
Replace all bare ComfyUI internal imports with centralized _load_module()
using importlib.util.spec_from_file_location(). This eliminates sys.path
shadowing attacks, removes the remove/re-insert gap window, and makes
import resolution deterministic regardless of working directory, install
layout, or prior sys.path state.

node_runtime.py — core rewrite:
- Add _load_module(): centralized importlib isolation layer that loads
  modules from explicit file paths verified against a ComfyUI root
  confirmed by _is_comfyui_directory() (checks for nodes.py marker)
- Add _is_comfyui_directory(): structural verification of candidate paths
- Add _find_from_extension_location(): walk up from __file__ via realpath
  to find ComfyUI root (handles symlinked installs)
- Rewrite get_comfyui_path(): multi-strategy fallback chain:
  (1) COMFYUI_PATH env var with verification, (2) relative extension walk,
  (3) CWD walk as depth-limited last resort (max 20 levels)
- Replace bare 'from nodes import NODE_CLASS_MAPPINGS' with _load_module()
- Replace bare 'import execution/server' with _load_module()
- Replace bare 'from main import load_extra_path_config' with _load_module()
  (alias "comfy_main" to prevent sys.modules cache collision)
- Replace bare 'from utils.extra_config import ...' with _load_module()
- Replace bare 'import comfy.options/cli_args' with _load_module()
- Replace bare 'import cuda_malloc' with _load_module()
- Rewrite add_comfyui_directory_to_sys_path(): idempotent insert-once,
  no remove/re-insert gap window
- Rewrite import_custom_nodes(): _load_module() for execution/nodes/server,
  eliminated sys.path.remove() that created a gap window for lazy imports
- Rewrite get_node_class_mappings(): _load_module() for nodes.py
- Replace all print() statements with logging.DEBUG (no path leaks to stdout)
- Add None guards on args attributes after cli_args module load

generator/render.py — generated script isolation:
- Embed _load_module(), _is_comfyui_directory(), _find_from_extension_location()
  in generated scripts via inspect.getsource()
- Add importlib.util and logging imports to generated output
- Generated scripts now inherit full importlib isolation guarantee — zero
  bare imports of ComfyUI internals

generator/generated_helpers.py:
- Export _load_module, _is_comfyui_directory, _find_from_extension_location
  for use by render.py

tests/test_import_path_resolution.py — new (14 test cases):
- TestIsComfyuiDirectory: structural verification against real ComfyUI checkout,
  rejection of empty/nonexistent directories
- TestLoadModule: module loading from explicit path, graceful None for missing
- TestShadowingResistance: malicious main.py and nodes.py at sys.path[0] are
  ignored; _load_module() always loads from verified file path
- TestSysPathIdempotence: insert-once behavior, no remove/re-insert in
  import_custom_nodes(), no print() statements in module source
- TestGeneratedScriptIsolation: generated output contains _load_module() and
  spec_from_file_location; zero bare ComfyUI imports
- TestGetComfyuiPath: env var strategy with verification, fallback chain

tests/test_upscale_model_loader_export.py — updated assertions:
- Replace "import comfy.options" / "import cuda_malloc" checks with
  _load_module() string pattern matching ("comfy.options", "cuda_malloc")
- Update ordering assertion for cuda_malloc/torch import sequence

Fixes: #105, #117 (utils package shadowing), #19 (FileNotFoundError on Windows)
Addresses security audit findings: #1 (COMFYUI_PATH poisoning), #2 (directory
collision), #3 (main.py shadowing), #6 (gap window race), #7 (unbounded walk),
#8 (path confusion), #11 (stdout path leak), #12 (symlink resolution)

Spec: docs/specs/harden-import-path-resolution.html
2026-05-10 00:03:19 -05:00

281 lines
9.6 KiB
Python

import importlib.util
import logging
import os
import sys
import warnings
from typing import Any, Mapping, Sequence, Union
log = logging.getLogger(__name__)
def _is_comfyui_directory(path: str) -> bool:
"""Verify a directory has ComfyUI structural markers (nodes.py)."""
if not os.path.isdir(path):
return False
return os.path.isfile(os.path.join(path, "nodes.py"))
def _load_module(module_name: str, filepath: str) -> Any:
"""Load a Python module from an explicit file path, bypassing sys.path.
This eliminates ALL bare import shadowing attacks by loading modules
from verified file paths instead of relying on sys.path resolution.
"""
if not os.path.isfile(filepath):
log.debug("Module file not found: %s (%s)", module_name, filepath)
return None
try:
spec = importlib.util.spec_from_file_location(module_name, filepath)
if spec is None or spec.loader is None:
log.debug("Could not create spec for %s at %s", module_name, filepath)
return None
mod = importlib.util.module_from_spec(spec)
sys.modules[module_name] = mod
spec.loader.exec_module(mod)
return mod
except Exception as e:
log.debug("Failed to load %s from %s: %s", module_name, filepath, e)
return None
def _find_from_extension_location() -> str | None:
"""Walk up from this file's location to find ComfyUI root."""
ext_dir = os.path.dirname(os.path.realpath(__file__))
candidate = ext_dir
for _ in range(10):
parent = os.path.dirname(candidate)
if parent == candidate:
break
candidate = parent
if os.path.basename(candidate) == "ComfyUI":
if _is_comfyui_directory(candidate):
return candidate
return None
def find_path(name: str, max_depth: int = 20) -> str | None:
"""Iteratively walk up from CWD to find a directory by name.
Depth-limited to prevent slow startup on deep trees.
Each candidate verified by _is_comfyui_directory() at the caller.
"""
candidate = os.getcwd()
for _ in range(max_depth):
parent = os.path.dirname(candidate)
if parent == candidate:
break
candidate = parent
if os.path.basename(candidate) == name:
return candidate
return None
def get_comfyui_path() -> str | None:
"""Resolve ComfyUI path via prioritized multi-strategy fallback.
Strategy order:
1. COMFYUI_PATH env var (verified with _is_comfyui_directory)
2. Relative walk from extension location (realpath + verified)
3. CWD walk (legacy fallback, depth-limited)
"""
p = os.environ.get("COMFYUI_PATH")
if p and _is_comfyui_directory(p):
return p
p = _find_from_extension_location()
if p:
return p
return find_path("ComfyUI", max_depth=20)
def add_comfyui_directory_to_sys_path() -> None:
"""Add the ComfyUI checkout to sys.path (idempotent — insert-once, no gap)."""
comfyui_path = get_comfyui_path()
if comfyui_path is not None and os.path.isdir(comfyui_path):
if comfyui_path not in sys.path:
sys.path.insert(0, comfyui_path)
log.debug("Added %s to sys.path", comfyui_path)
def add_extra_model_paths() -> None:
"""Load ComfyUI extra model paths configuration when available."""
comfyui_path = get_comfyui_path()
if comfyui_path is None:
log.debug("Cannot load extra model paths: ComfyUI path not found")
return
# Try main.py first, then utils/extra_config.py — both via _load_module()
main_mod = _load_module("comfy_main", os.path.join(comfyui_path, "main.py"))
if main_mod is not None and hasattr(main_mod, "load_extra_path_config"):
load_extra_path_config = getattr(main_mod, "load_extra_path_config")
else:
log.debug("main.py not available, trying utils/extra_config.py")
extra_config_mod = _load_module(
"extra_config", os.path.join(comfyui_path, "utils", "extra_config.py")
)
if extra_config_mod is None or not hasattr(
extra_config_mod, "load_extra_path_config"
):
log.debug("Could not find load_extra_path_config in either path")
return
load_extra_path_config = getattr(extra_config_mod, "load_extra_path_config")
extra_model_paths = find_path("extra_model_paths.yaml")
if extra_model_paths is not None:
load_extra_path_config(extra_model_paths)
else:
log.debug("Could not find the extra_model_paths config file.")
def bootstrap_comfyui_runtime() -> None:
"""Mirror the allocator-related ComfyUI startup steps before torch import."""
add_comfyui_directory_to_sys_path()
comfyui_path = get_comfyui_path()
if comfyui_path is None:
log.debug("bootstrap_comfyui_runtime: ComfyUI path not found")
return
options_mod = _load_module(
"comfy.options", os.path.join(comfyui_path, "comfy", "options.py")
)
if options_mod is not None:
options_mod.enable_args_parsing()
cli_args_mod = _load_module(
"comfy.cli_args", os.path.join(comfyui_path, "comfy", "cli_args.py")
)
args = getattr(cli_args_mod, "args", None) if cli_args_mod else None
if os.name == "nt":
os.environ["MIMALLOC_PURGE_DELAY"] = "0"
if args is not None and args.default_device is not None:
default_dev = args.default_device
devices = list(range(32))
devices.remove(default_dev)
devices.insert(0, default_dev)
devices = ",".join(map(str, devices))
os.environ["CUDA_VISIBLE_DEVICES"] = str(devices)
os.environ["HIP_VISIBLE_DEVICES"] = str(devices)
if args is not None and args.cuda_device is not None:
os.environ["CUDA_VISIBLE_DEVICES"] = str(args.cuda_device)
os.environ["HIP_VISIBLE_DEVICES"] = str(args.cuda_device)
os.environ["ASCEND_RT_VISIBLE_DEVICES"] = str(args.cuda_device)
if args is not None and args.oneapi_device_selector is not None:
os.environ["ONEAPI_DEVICE_SELECTOR"] = args.oneapi_device_selector
if (
args is not None
and args.deterministic
and "CUBLAS_WORKSPACE_CONFIG" not in os.environ
):
os.environ["CUBLAS_WORKSPACE_CONFIG"] = ":4096:8"
cuda_malloc_mod = _load_module(
"cuda_malloc", os.path.join(comfyui_path, "cuda_malloc.py")
)
if (
cuda_malloc_mod is not None
and hasattr(cuda_malloc_mod, "get_torch_version_noimport")
and "rocm" in cuda_malloc_mod.get_torch_version_noimport()
):
os.environ["OCL_SET_SVM_SIZE"] = "262144"
def cleanup_comfyui_runtime(unload_models: bool | None = None) -> None:
"""Best-effort cleanup for embedded or repeated generated-script execution."""
import gc
def run_cleanup_hook(name: str, should_run: bool = True) -> None:
if not should_run or not hasattr(model_management, name):
return
cleanup_fn = getattr(model_management, name)
try:
cleanup_fn()
except Exception as exc:
warnings.warn(
f"ComfyUI cleanup hook {name} failed during teardown: {exc}",
RuntimeWarning,
stacklevel=2,
)
should_unload = unload_models
if should_unload is None:
should_unload = os.environ.get(
"COMFYUI_TOPYTHON_UNLOAD_MODELS", ""
).lower() in {
"1",
"true",
"yes",
"on",
}
try:
import comfy.model_management as model_management
except ModuleNotFoundError:
gc.collect()
return
run_cleanup_hook("cleanup_models_gc")
run_cleanup_hook("unload_all_models", should_run=should_unload)
run_cleanup_hook("soft_empty_cache")
gc.collect()
def import_custom_nodes() -> None:
"""Initialize ComfyUI custom nodes in the exporter runtime.
Uses _load_module() for all ComfyUI imports — no bare imports,
no sys.path remove/re-insert gap.
"""
comfyui_path = get_comfyui_path()
if comfyui_path is None:
log.debug("import_custom_nodes: ComfyUI path not found")
return
# Idempotent insert-once — never removes from sys.path
if comfyui_path not in sys.path:
sys.path.insert(0, comfyui_path)
import asyncio
execution_mod = _load_module(
"execution", os.path.join(comfyui_path, "execution.py")
)
nodes_mod = _load_module("nodes", os.path.join(comfyui_path, "nodes.py"))
server_mod = _load_module("server", os.path.join(comfyui_path, "server.py"))
if execution_mod is None or server_mod is None:
log.debug("import_custom_nodes: could not load required modules")
return
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
server_instance = server_mod.PromptServer(loop)
execution_mod.PromptQueue(server_instance)
if nodes_mod is not None and hasattr(nodes_mod, "init_extra_nodes"):
asyncio.run(nodes_mod.init_extra_nodes())
def get_node_class_mappings() -> dict:
"""Load ComfyUI node mappings on demand via _load_module()."""
add_comfyui_directory_to_sys_path()
comfyui_path = get_comfyui_path()
if comfyui_path is None:
log.debug("get_node_class_mappings: ComfyUI path not found")
return {}
nodes_mod = _load_module("nodes", os.path.join(comfyui_path, "nodes.py"))
if nodes_mod is None:
return {}
return getattr(nodes_mod, "NODE_CLASS_MAPPINGS", {})
def get_value_at_index(obj: Union[Sequence, Mapping], index: int) -> Any:
"""Return a sequence or mapping result item by index."""
try:
return obj[index]
except KeyError:
return obj["result"][index]