Subject: Re: [PATCH net-next v18 07/25] ovpn: implement basic TX path (UDP)

From: Sabrina Dubroca <[email-masked]>
Date: Mon, 3 Feb 2025 10:52:41 +0100

2025-01-13, 10:31:26 +0100, Antonio Quartulli wrote:
> +static void ovpn_encrypt_post(struct sk_buff *skb, int ret)
> +{
> +	struct ovpn_peer *peer = ovpn_skb_cb(skb)->peer;
> +
> +	if (unlikely(ret < 0))
> +		goto err;
> +
> +	skb_mark_not_on_list(skb);
> +
> +	switch (peer->sock->sock->sk->sk_protocol) {

We have a ref on the peer, but not on the ovpn_sock. DEL_PEER could
have detached the sock by the time the crypto completes.

(unfortunately I don't have any idea to fix this yet)

> +	case IPPROTO_UDP:
> +		ovpn_udp_send_skb(peer, skb);
> +		break;
> +	default:
> +		/* no transport configured yet */
> +		goto err;
> +	}
> +	/* skb passed down the stack - don't free it */
> +	skb = NULL;
> +err:
> +	if (unlikely(skb))
> +		dev_core_stats_tx_dropped_inc(peer->ovpn->dev);
> +	ovpn_peer_put(peer);
> +	kfree_skb(skb);
> +}

-- 
Sabrina