Guard against invalid PIDs in process operations#4401
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amirejaz merged 1 commit intostacklok:mainfrom Mar 27, 2026
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On Unix, kill(0, sig) sends the signal to every process in the calling process's group. KillProcess(0) would SIGTERM thv itself and any child processes sharing its group. FindProcess(0) falsely reports "alive" via kill(0, 0). Both can be reached when a status file contains PID 0 due to crashes or races during proxy startup. Fixes stacklok#4400 Co-Authored-By: Claude <noreply@anthropic.com> Signed-off-by: Greg Katz <gkatz@indeed.com>
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #4401 +/- ##
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- Coverage 69.51% 69.51% -0.01%
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Files 485 485
Lines 49805 49811 +6
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+ Hits 34623 34627 +4
- Misses 12503 12512 +9
+ Partials 2679 2672 -7 ☔ View full report in Codecov by Sentry. 🚀 New features to boost your workflow:
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amirejaz
approved these changes
Mar 27, 2026
This was referenced Mar 30, 2026
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Summary
KillProcess,FindProcess, andWaitForExit, causing process group signals or false-positive liveness checks. See Guard against PID 0 in KillProcess and FindProcess #4400 for root cause details.pid <= 0guards that return a clear error. All existing callers already handle errors gracefully, so no caller changes are needed.Fixes #4400
Type of change
Test plan
task test)task lint-fix)thv run+thv rmwork normally with the guards in placeChanges
pkg/process/kill_unix.gopid <= 0early returnpkg/process/kill_windows.gopkg/process/find_unix.gopid <= 0early returnpkg/process/find_windows.gopkg/process/wait.gopid <= 0early returnpkg/process/pid_validation_test.goDoes this introduce a user-facing change?
No.
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