🛡️ Sentinel: [CRITICAL] Fix deserialization sinks missing from taint propagation

[tachyon-beep]

🚨 Severity: CRITICAL
💡 Vulnerability: The static analyzer was missing dill.load, dill.loads, jsonpickle.decode, joblib.load, torch.load, and numpy.load in its _SERIALISATION_SINKS mapping.
🎯 Impact: Untrusted data flowing into these dangerous deserialization functions might not have shed validation provenance correctly, leading to false negatives in security scanning.
🔧 Fix: Added these missing deserialization sinks to the _SERIALISATION_SINKS set in src/wardline/scanner/taint/variable_level.py. Adjusted a unit test in src/wardline/scanner/rules/untrusted_to_deserialization.py to ensure it passes with the new taint tracking behavior.
✅ Verification: Ran uv run pytest tests/unit/scanner/taint/test_variable_level.py and uv run pytest tests/unit/scanner/rules/test_rule_examples_meta.py locally and all passed.

---

PR created automatically by Jules for task 17940626351355831895 started by @tachyon-beep

[google-labs-jules]

👋 Jules, reporting for duty! I'm here to lend a hand with this pull request.

When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down.

I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job!

For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with @jules. You can find this option in the Pull Request section of your global Jules UI settings. You can always switch back!

New to Jules? Learn more at jules.google/docs.

---

For security, I will only act on instructions from the user who triggered this task.

[Copilot]

Pull request overview

This PR hardens Wardline’s Python taint propagation by ensuring additional third-party (de)serialization entrypoints are treated as representation-boundary calls, preventing validated inputs from incorrectly conferring “trusted” provenance onto deserialized outputs and reducing security-scanning false negatives.

Changes:

• Added missing third-party deserialization functions (dill.*, jsonpickle.decode, joblib.load, torch.load, numpy.load) to the core _SERIALISATION_SINKS frozenset used by variable-level taint propagation.
• Updated the PY-WL-106 rule’s “clean” example so it remains clean under the new taint tracking semantics.
• Documented the incident/learning in .jules/sentinel.md.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/wardline/scanner/taint/variable_level.py	Expands core serialization/deserialization sink list so these calls shed validation provenance to UNKNOWN_RAW.
src/wardline/scanner/rules/untrusted_to_deserialization.py	Adjusts rule metadata example to avoid unintended findings after taint behavior changes.
.jules/sentinel.md	Adds a Sentinel log entry capturing the vulnerability, learning, and prevention guidance.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.