🛡️ Sentinel: [MEDIUM] Fix DoS vulnerability via Process deadlock

[NSEvent]

🚨 Severity: MEDIUM
💡 Vulnerability: Execution framework deadlock/DoS when a spawned process emits large output.
🎯 Impact: An attacker or a misconfigured script could emit >64KB of data to stdout/stderr, causing the application's automation executor to hang indefinitely (deadlock).
🔧 Fix: Reordered the execution flow to read the pipe data before calling waitUntilExit().
✅ Verification: Code statically verified. Issue has been fixed in SystemCommandExecutor.swift before, and is now also fixed in AutomationExecutor.swift.

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PR created automatically by Jules for task 917862636345387285 started by @NSEvent

Summary by CodeRabbit

• Bug Fixes

  • Fixed an issue where long-running process output could cause the app to hang while waiting for completion.
  • Improved process handling so output is collected before waiting for the process to exit, reducing deadlock risk.

• Documentation

  • Added guidance describing the safe way to handle process output when working with external commands.

[google-labs-jules]

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 4186a8b2-350d-4a46-9aef-23e93262d6da

📥 Commits

Reviewing files that changed from the base of the PR and between c431981 and 02b3550.

📒 Files selected for processing (2)

• .Jules/sentinel.md
• TriggerKit/Sources/TriggerKitRuntime/AutomationExecutor.swift

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📝 Walkthrough

Walkthrough

This change reorders subprocess handling in AutomationExecutor.swift so pipe output is fully read before waiting for process termination, avoiding a deadlock when child process output exceeds the OS pipe buffer. A corresponding sentinel.md entry documents this deadlock risk.

Changes

Process pipe deadlock fix

Layer / File(s)	Summary
Read pipe before waiting on process exit TriggerKit/Sources/TriggerKitRuntime/AutomationExecutor.swift, .Jules/sentinel.md	runProcess now drains pipe data before calling waitUntilExit(), with an added comment explaining the deadlock risk; sentinel.md documents the DoS deadlock scenario and mitigation guidance.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Suggested reviewers: NSEvent

Poem
A rabbit peeked inside the pipe,
"Drain it first," it gave a gripe,
Read the bytes before you wait,
Or deadlock seals the process' fate,
Now hops along, no more delay,
Output flows the proper way. 🐇

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: fixing a process deadlock that can cause a denial-of-service.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch sentinel/fix-process-deadlock-917862636345387285

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