Calling Wait() inside a loop blocks Done()

Description

Calls to `sync.WaitGroup.Wait` inside a loop can block the call to `sync.WaitGroup.Done`, leading to improper locking and potential deadlocks.

Examples

Insecure Code

var wg sync.WaitGroup
for i := 0; i < 10; i++ {
  go func() {
    defer wg.Done()
  }()
  wg.Wait()
}

Secure Code

var wg sync.WaitGroup
for i := 0; i < 10; i++ {
  go func() {
    defer wg.Done()
  }()
}
wg.Wait()

Remediation

Move the call to `sync.WaitGroup.Wait` outside the loop to ensure proper synchronization.

Rule Details

Field	Value
ID	CODE-0255
Category	Concurrency
Severity	MEDIUM
CWE	CWE-667
Confidence	MEDIUM
Impact	MEDIUM
Likelihood	MEDIUM
Exploitability	MODERATE
Tags	go, concurrency, synchronization
OWASP	N/A

References

• https://go101.org/article/concurrent-common-mistakes.html

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