How can you avoid a goroutine leak in this code?

func findUser(ctx context.Context, login string) (*User, error) {
    ch := make(chan *User)
    go func() {
            ch <- findUserInDB(login)
    }()
    select {
    case user := <-ch:
            return user, nil
    case <-ctx.Done():
            return nil, fmt.Errorf("timeout")
    }
}