# Channel Misuse

- ID: go-channel-misuse
- Severity: HIGH
- CWE: CWE-833 (CWE-833)
- Languages: Go

## Description

Improper channel usage can cause deadlocks, goroutine leaks, or panics.
Common issues include send/receive on unbuffered channel in same goroutine,
not closing channels, and sending on closed channels.

## Detection Message

Channel misuse can cause:
- Deadlocks (blocking operations without receiver/sender)
- Goroutine leaks (receivers waiting forever on unclosed channel)
- Panics (sending on closed channel)


## Remediation

1. Use buffered channels when sender/receiver in same goroutine:
```go
ch := make(chan int, 1)  // Buffered
ch <- 42
val := <-ch
```

2. Always close channels when done sending:
```go
go func() {
    defer close(ch)  // Prevents goroutine leaks
    for _, item := range items {
        ch <- item
    }
}()
```

3. Use select with timeout/context for network operations:
```go
select {
case result := <-resultCh:
    handle(result)
case <-ctx.Done():
    return ctx.Err()
case <-time.After(5 * time.Second):
    return errors.New("timeout")
}
```

4. Never send on closed channel:
```go
// Use sync primitives to coordinate close
var once sync.Once
closeCh := func() { once.Do(func() { close(ch) }) }
```

## Documentation

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