Re: [bpf PATCH v2 6/6] bpf: sockmap/tls, close can race with map free

[Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>]

On Mon, 08 Jul 2019 19:15:18 +0000, John Fastabend wrote:
> @@ -836,22 +841,39 @@ static int tls_init(struct sock *sk)

There is a goto out above this which has to be turned into return 0;
if out now releases the lock.

>  	if (sk->sk_state != TCP_ESTABLISHED)
>  		return -ENOTSUPP;
>  
> +	tls_build_proto(sk);
> +
>  	/* allocate tls context */
> +	write_lock_bh(&sk->sk_callback_lock);
>  	ctx = create_ctx(sk);
>  	if (!ctx) {
>  		rc = -ENOMEM;
>  		goto out;
>  	}
>  
> -	tls_build_proto(sk);
>  	ctx->tx_conf = TLS_BASE;
>  	ctx->rx_conf = TLS_BASE;
>  	ctx->sk_proto = sk->sk_prot;
>  	update_sk_prot(sk, ctx);
>  out:
> +	write_unlock_bh(&sk->sk_callback_lock);
>  	return rc;
>  }