meshery/meshery

[Performance] Prevent double-unlock panic in startNighthawkServer

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#18978 opened on Apr 29, 2026

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help wanted

Description

Current Behavior

startNighthawkServer locks nighthawkStatus with a deferred unlock, but it also manually unlocks the same mutex on two error paths.

That creates a double-unlock risk that can panic the server while handling a failed Nighthawk startup.

Expected Behavior

The function should unlock the mutex exactly once on every path.

Screenshots/Logs

Relevant code path:

  • server/helpers/load_test_interface.go
  • defer nighthawkStatus.Unlock() near the top of startNighthawkServer
  • extra nighthawkStatus.Unlock() calls before returning errors

Environment

  • Host OS: Linux
  • Platform: Kubernetes
  • Meshery Server Version: current master
  • Meshery Client Version: current master

To Reproduce

  1. Trigger the Nighthawk startup path.
  2. Make cmd.Start() fail, or make os.Stat(transformCommand) fail.
  3. Observe the function hit a manual unlock and then hit the deferred unlock on return.

Contributor Guides and Handbook

Contributor guide

Tech stack
go
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Go programmingMutex locking patterns
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
45
Research direction
The fix is in server/helpers/load test interface.go. Remove the explicit `nighthawkStatus.Unlock()` calls on the two error paths and rely solely on the deferred unlock. Ensure that no double unlock occurs. The change is small and localized.