waitgroup-wait-inside-loop.yaml

rules:
- id: waitgroup-wait-inside-loop
  message: >-
    Calling `$WG.Wait()` inside a loop blocks the call to `$WG.Done()`
  languages: [go]
  severity: WARNING
  metadata:
    category: security
    cwe: "CWE-667: Improper Locking"
    subcategory: [vuln]
    confidence: MEDIUM
    likelihood: MEDIUM
    impact: MEDIUM
    technology: [--no-technology--]
    description: "Calls to `sync.WaitGroup.Wait` inside a loop"
    references:
      - https://go101.org/article/concurrent-common-mistakes.html

  patterns:
    - pattern-either: 
      - pattern: |
          var $WG sync.WaitGroup
          ...
          for ... {
            ...
            go func(...){
              ...
              defer $WG.Done()
              ...
            }()
            ...
            $WG.Wait()
            ...
          }
      - pattern: |
          $WG := &sync.WaitGroup{}
          ...
          for ... {
            ...
            go func(...){
              ...
              defer $WG.Done()
              ...
            }()
            ...
            $WG.Wait()
            ...
          }
      - pattern: |
          var $WG sync.WaitGroup
          ...
          for ... {
            ...
            go func(...){
              ...
              $WG.Done()
              ...
            }()
            ...
            $WG.Wait()
            ...
          }
      - pattern: |
          $WG := &sync.WaitGroup{}
          ...
          for ... {
            ...
            go func(...){
              ...
              $WG.Done()
              ...
            }()
            ...
            $WG.Wait()
            ...
          }