static void mac80211_hwsim_monitor_rx(struct ieee80211_hw *hw,
				      struct sk_buff *tx_skb,
				      struct ieee80211_channel *chan)
{
	struct mac80211_hwsim_data *data = hw->priv;
	struct sk_buff *skb;
	struct hwsim_radiotap_hdr *hdr;
	u16 flags;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx_skb);
	struct ieee80211_rate *txrate = ieee80211_get_tx_rate(hw, info);

	if (WARN_ON(!txrate))
		return;

	if (!netif_running(hwsim_mon))
		return;

	skb = skb_copy_expand(tx_skb, sizeof(*hdr), 0, GFP_ATOMIC);
	if (skb == NULL)
		return;

	hdr = skb_push(skb, sizeof(*hdr));
	hdr->hdr.it_version = PKTHDR_RADIOTAP_VERSION;
	hdr->hdr.it_pad = 0;
	hdr->hdr.it_len = cpu_to_le16(sizeof(*hdr));
	hdr->hdr.it_present = cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
					  (1 << IEEE80211_RADIOTAP_RATE) |
					  (1 << IEEE80211_RADIOTAP_TSFT) |
					  (1 << IEEE80211_RADIOTAP_CHANNEL));
	hdr->rt_tsft = __mac80211_hwsim_get_tsf(data);
	hdr->rt_flags = 0;
	hdr->rt_rate = txrate->bitrate / 5;
	hdr->rt_channel = cpu_to_le16(chan->center_freq);
	flags = IEEE80211_CHAN_2GHZ;
	if (txrate->flags & IEEE80211_RATE_ERP_G)
		flags |= IEEE80211_CHAN_OFDM;
	else
		flags |= IEEE80211_CHAN_CCK;
	hdr->rt_chbitmask = cpu_to_le16(flags);

	skb->dev = hwsim_mon;
	skb_reset_mac_header(skb);
	skb->ip_summed = CHECKSUM_UNNECESSARY;
	skb->pkt_type = PACKET_OTHERHOST;
	skb->protocol = htons(ETH_P_802_2);
	memset(skb->cb, 0, sizeof(skb->cb));
	netif_rx(skb);
}

The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.