🛡️ Sentinel: [CRITICAL] Fix Resource Exhaustion via subprocess.call Timeout Leak

[ManupaKDU]

🚨 Severity

CRITICAL

💡 Vulnerability

The is_reachable function executed the ping utility using subprocess.call with a timeout parameter. However, subprocess.call does not kill the child process when the timeout expires; it only raises a TimeoutExpired exception. This leaves the ping process running indefinitely in the background, which can lead to resource exhaustion (DoS) as more timeout events occur.

🎯 Impact

Denial of Service (DoS) due to resource exhaustion. If many scan requests are made with unresponsive IP addresses, the background ping processes will pile up, consuming process IDs (PIDs), memory, and file descriptors until the host OS limits are hit and the service crashes.

🔧 Fix

Updated is_reachable in testping1.py to use subprocess.run() instead of subprocess.call(), as subprocess.run() inherently kills the child process upon timeout, preventing resource leaks. Also updated the unit tests in test_testping1.py to mock subprocess.run.

✅ Verification

1. Run tests with python3 -m unittest test_testping1.py and verify all tests pass.
2. Manually test using a known unresponsive IP (e.g. within a local subnet that does not exist) with a large number of max workers, and use ps aux | grep ping to verify there are no lingering ping processes after the script finishes.

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PR created automatically by Jules for task 12954097720962151169 started by @ManupaKDU

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