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

Jakub Kicinski
2019-07-10T02:38:53Z

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);