Re: [PATCH net-next v6 1/2] nfc: llcp_core: Hold a ref to llcp_local->dev when holding a ref to llcp_local

From: Krzysztof Kozlowski
Date: Mon Dec 18 2023 - 04:39:20 EST


On 17/12/2023 14:11, Siddh Raman Pant wrote:
> static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
> @@ -959,8 +974,18 @@ static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
> }
>
> new_sock = nfc_llcp_sock(new_sk);
> - new_sock->dev = local->dev;
> +
> new_sock->local = nfc_llcp_local_get(local);
> + if (!new_sock->local) {
> + reason = LLCP_DM_REJ;
> + release_sock(&sock->sk);
> + sock_put(&sock->sk);
> + sock_put(&new_sock->sk);

Why is this needed? Which part earlier gets the reference?

> + nfc_llcp_sock_free(new_sock);

This order is still wrong. Unwinding is almost always done in reversed
order, for good reasons. Why do you unwind in other order?

> + goto fail;
> + }
> +
> + new_sock->dev = local->dev;
> new_sock->rw = sock->rw;
> new_sock->miux = sock->miux;
Best regards,
Krzysztof