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

[Jakub Kicinski]

On Mon, 08 Jul 2019 19:15:18 +0000, John Fastabend wrote:
> @@ -352,15 +354,18 @@ static void tls_sk_proto_close(struct sock *sk, long 
> timeout)
>       if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE)
>               goto skip_tx_cleanup;
>  
> -     sk->sk_prot = ctx->sk_proto;
>       tls_sk_proto_cleanup(sk, ctx, timeo);
>  
>  skip_tx_cleanup:
> +     write_lock_bh(&sk->sk_callback_lock);
> +     icsk->icsk_ulp_data = NULL;

Is ulp_data pointer now supposed to be updated under the
sk_callback_lock?

> +     if (sk->sk_prot->close == tls_sk_proto_close)
> +             sk->sk_prot = ctx->sk_proto;
> +     write_unlock_bh(&sk->sk_callback_lock);
>       release_sock(sk);
>       if (ctx->rx_conf == TLS_SW)
>               tls_sw_release_strp_rx(ctx);
> -     sk_proto_close(sk, timeout);
> -
> +     ctx->sk_proto_close(sk, timeout);
>       if (ctx->tx_conf != TLS_HW && ctx->rx_conf != TLS_HW &&
>           ctx->tx_conf != TLS_HW_RECORD && ctx->rx_conf != TLS_HW_RECORD)
>               tls_ctx_free(ctx);