3 Commits

Author SHA1 Message Date
Mohamed Hegazy
38b298d5b2
security-guidance: pass core.quotePath=false to diff feeders (#2082)
Fixes anthropics/claude-plugins-official#2082 — diff feeders use git's
default quotePath setting, which C-quotes any path with a non-ASCII
byte. The downstream parsers in gitutil.parse_diff_into_files /
gitutil.extract_file_paths_from_diff match the diff header with
`re.match(r'^a/(.+?) b/(.+)$', ...)`, which only sees the raw
`a/path b/path` form. The C-quoted `"a/\303\201vila/..."` form
slips past the regex, the `continue` fires, and the file is silently
dropped from review.

Effect: a vulnerable file like `Ávila/payment.py` with
`os.system('curl ' + user_input)` never reaches the LLM reviewer.
False negative in exactly the direction the plugin exists to catch.

Sibling of #2056 / #2075: those fixed the UTF-8 decode of the
subprocess output (text=True crashed the reader thread on Windows
cp1252). This one fixes the diff-feeder commands themselves — the
name-only helpers (_git_name_only, _git_status_porcelain) already
pass core.quotePath=false for this exact reason; the diff-text
feeders were the holdouts.

Fix: add `-c core.quotePath=false` to 4 git invocations:

  - gitutil._git_diff_range            (push-sweep feed)
  - gitutil.get_git_diff                (Stop-hook feed)
  - security_reminder_hook commit-review `git diff` (amend delta)
  - security_reminder_hook commit-review `git show`  (post-amend)

With the flag, git emits raw UTF-8 in the diff header
(`a/Ávila/payment.py`), the regex matches, and both files (the
non-ASCII vulnerable one + any ASCII control file) flow through to
review correctly.

Verified locally on macOS Python 3.13:

  - py_compile clean on both files.
  - Existing 45 smoke + extensibility tests still pass.
  - 8 new tests in test_diff_parser_non_ascii.py (added to internal
    test suite at sg-staging/tests/, not in this PR):

      * 2 static-shape: gitutil._git_diff_range and get_git_diff both
        contain `core.quotePath=false` in their source.
      * 2 commit-review static: every subprocess.run in
        handle_commit_review_posttooluse that mentions `"diff"` or
        `"show"` also passes the flag. Catches the regression
        class where a new diff/show call site is added without
        plumbing the flag through.
      * 4 end-to-end with a real git repo containing a
        `Ávila/payment.py` baseline-and-edit:
          - WITHOUT flag: header is C-quoted, both parsers drop the
            non-ASCII file (demonstrates the bug).
          - WITH flag: header is raw UTF-8, both parsers see the file.
          - parse_diff_into_files (the other parse path) also keeps
            the file with the flag.
          - get_git_diff end-to-end produces unquoted output whose
            file list includes the non-ASCII path.

  - 53/53 pass total (45 existing + 8 new) in 3.41s.

NOT verified end-to-end with a real CC commit-review fire on a
non-ASCII path. The static-shape tests catch the regression and the
end-to-end git-repo tests pin parser behavior, but the actual
LLM-review-with-vuln-found path requires runtime verification against
an Anthropic-API-credentialed CC session.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-29 07:56:22 -07:00
Mohamed Hegazy
6a63e35e75
security-guidance: lenient UTF-8 decode in 6 git-subprocess helpers (#2056)
Fixes anthropics/claude-plugins-official#2056 — on Windows, when the
worktree contains an untracked file whose name has a character undefined
in cp1252 (accented capitals like Á Í Ï Ð Ý, most CJK, emoji), the
UserPromptSubmit hook crashes:

  Exception in thread Thread-5 (_readerthread):
    UnicodeDecodeError: 'charmap' codec can't decode byte 0x81
  Traceback (most recent call last):
    File diffstate.py, line 338, in _list_untracked
      for p in r.stdout.split('\\0'):
  AttributeError: 'NoneType' object has no attribute 'split'

Non-blocking (UPS failures still let the prompt through) but the
baseline-untracked snapshot is silently lost, so the Stop-hook review
mis-handles pre-existing untracked files.

Root cause (reporter's diagnosis, verified):

1. core.quotePath=false makes git emit raw UTF-8 for non-ASCII filenames.
2. subprocess.run(..., text=True) decodes via
   locale.getpreferredencoding(False) in strict mode — on Windows that
   is cp1252, in which 0x81 / 0x8D / 0x8F / 0x90 / 0x9D are undefined.
   Those bytes appear in the UTF-8 encodings of Á (C3 81), Í (C3 8D),
   Ï (C3 8F), Ð (C3 90), Ý (C3 9D), and a large fraction of CJK / emoji
   codepoints.
3. The decode runs in the subprocess reader thread. The thread raises
   UnicodeDecodeError, threading prints 'Exception in thread Thread-N',
   subprocess.run returns with stdout=None. The handler then does
   None.split('\\0') -> AttributeError, which is NOT in the narrow
   except (TimeoutExpired, FileNotFoundError, OSError) tuple, so it
   escapes the helper, propagates out of UserPromptSubmit's
   ThreadPoolExecutor.result(), and exits the hook non-zero.

This is internally inconsistent: gitutil._git_diff_range,
security_reminder_hook._reflog_amend_lookup (line ~540), and the commit
diff loop (line ~1115) already do bytes + decode utf-8/replace, with
comments explicitly noting that text=True would crash. The fix below
extends that established pattern to the helpers that were holdouts.

Affected helpers (6 total):

  - diffstate._list_untracked            <- reporter, hot path, CRITICAL
  - diffstate.capture_git_baseline       <- reporter, latent
  - diffstate.get_baseline_file_content  <- audit, file content read, HIGH
  - gitutil._git_name_only                <- reporter, latent
  - gitutil._git_status_porcelain         <- reporter, latent
  - gitutil._git_reflog_recent_commits    <- audit, embeds %gs commit msg, HIGH

For each one:

  - Drop text=True from subprocess.run.
  - Decode r.stdout / r.stderr as .decode('utf-8', errors='replace').
  - Add ValueError to the except tuple as defense against any future
    strict-decode regression (UnicodeDecodeError is a ValueError
    subclass; including it explicitly degrades the helper to its
    empty/None return instead of escaping out of the hook).

Verified locally on macOS Python 3.13:

  - py_compile clean on both files.
  - 45 existing smoke + extensibility tests still pass.
  - 21 new internal tests (not in this PR — added to the team's local
    test suite at staging/tests/test_unicode_decode.py):
      * 18 static-shape parametrized: each of the 6 fixed helpers has
        no text=True in its subprocess calls, contains errors='replace',
        and lists ValueError in its except.
      * Deterministic end-to-end: create real git repo + Ávila_report.txt
        untracked, call _list_untracked, verify it returns
        {'Ávila_report.txt': <mtime>} without crashing.
      * Deterministic end-to-end: same for capture_git_baseline (verifies
        the latent stderr-warning case stays valid).
      * Deterministic end-to-end: get_baseline_file_content on a file
        whose content has 山田太郎 + 🎉; verify the bytes round-trip
        through the decode.
  - 66/66 tests pass total (45 existing + 21 new).

NOT verified end-to-end on Windows — would need actual cp1252 strict
decode to fire. Reporter has the deterministic repro and will
re-verify on their Win11 / Python 3.14.x setup before merge.

Not in this PR (defense-in-depth, lower risk):

  - 3 git rev-parse calls returning path output (gitutil._find_git_index,
    _git_toplevel, _git_dir) could fail on Windows if cwd is in a
    non-ASCII install directory. Same fix shape but unreported and
    much lower probability — worth a separate follow-up if anyone
    actually hits it.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-28 23:15:16 -07:00
Mohamed Hegazy
0bde168648
Update security-guidance plugin 2026-05-26 14:06:52 -07:00