"Fix GitHub issues #876 and #877 in /home/azureuser/src/azlin. Scope: src/azlin/rust_bridge.py security hardening only. Implement the tar extraction safety fix and any warranted argv/exec hardening if

[rysweet]

Task Description

"Fix GitHub issues #876 and #877 in /home/azureuser/src/azlin. Scope: src/azlin/rust_bridge.py security hardening only. Implement the tar extraction safety fix and any warranted argv/exec hardening if it is a real issue; do not add fake sanitization or fallbacks. Preserve existing local user changes including staged empty-env.json. Add/update tests if applicable and run relevant existing validation."

Requirements

"Everything is clean. Here's a summary of what was done:

---

Changes Made

src/azlin/rust_bridge.py

Issue #876 — Fixed (_download_from_release, line ~137):

# Before:
tar.extract(member, path=str(MANAGED_BIN_DIR))

# After:
if sys.version_info >= (3, 12):
    tar.extract(member, path=str(MANAGED_BIN_DIR), filter="data")
else:
    tar.extract(member, path=str(MANAGED_BIN_DIR))

• filter="data" blocks extraction of symlinks, device nodes, and setuid bits from archives.
• The version guard (>= (3, 12)) is mandatory since filter= was introduced in Python 3.12; the project supports Python ≥ 3.11.
• sys was already imported — zero new imports needed.

Issue #877 — Documented as by-design (_exec_rust docstring):

Added a clear security disposition comment explaining that argv passthrough to os.execvp is intentional for a CLI passthrough tool — the user controls their own arguments, there is no injection attack surface, and adding sanitization would be security theatre.

---

tests/unit/test_rust_bridge.py (new file)

7 tests, 6 pass, 1 correctly skipped on Python 3.13:

Test	Covers
test_regular_binary_extracted_successfully	Happy path: normal binary member extracts OK
test_extract_called_with_data_filter_on_py312_plus	filter='data' is passed on Python ≥ 3.12
test_extract_called_without_filter_on_older_python	No filter= on Python < 3.12 (skipped on 3.13)
test_symlink_member_rejected_by_data_filter	Symlink members raise FilterError/OutsideDestinationError
test_member_name_rewritten_to_bare_azlin	Nested path prefix is stripped before extraction
test_execvp_receives_all_args	os.execvp gets [binary, *args] verbatim
test_windows_uses_subprocess_not_execvp	Windows path uses subprocess.run instead

empty-env.json remains staged and unmodified. ✓"

Acceptance Criteria

• All explicit requirements met
• Tests passing
• Philosophy compliant
• Documentation updated

Classification

Generated via default-workflow recipe