static void hwsim_send_nullfunc(struct mac80211_hwsim_data *data, u8 *mac,
				struct ieee80211_vif *vif, int ps)
{
	struct hwsim_vif_priv *vp = (void *)vif->drv_priv;
	struct sk_buff *skb;
	struct ieee80211_hdr *hdr;

	if (!vp->assoc)
		return;

	wiphy_dbg(data->hw->wiphy,
		  "%s: send data::nullfunc to %pM ps=%d\n",
		  __func__, vp->bssid, ps);

	skb = dev_alloc_skb(sizeof(*hdr));
	if (!skb)
		return;
	hdr = skb_put(skb, sizeof(*hdr) - ETH_ALEN);
	hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_DATA |
					 IEEE80211_STYPE_NULLFUNC |
					 IEEE80211_FCTL_TODS |
					 (ps ? IEEE80211_FCTL_PM : 0));
	hdr->duration_id = cpu_to_le16(0);
	memcpy(hdr->addr1, vp->bssid, ETH_ALEN);
	memcpy(hdr->addr2, mac, ETH_ALEN);
	memcpy(hdr->addr3, vp->bssid, ETH_ALEN);

	rcu_read_lock();
	mac80211_hwsim_tx_frame(data->hw, skb,
				rcu_dereference(vif->chanctx_conf)->def.chan);
	rcu_read_unlock();
}

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