static int sta_info_insert_check(struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;

	/*
	 * Can't be a WARN_ON because it can be triggered through a race:
	 * something inserts a STA (on one CPU) without holding the RTNL
	 * and another CPU turns off the net device.
	 */
	if (unlikely(!ieee80211_sdata_running(sdata)))
		return -ENETDOWN;

	if (WARN_ON(ether_addr_equal(sta->sta.addr, sdata->vif.addr) ||
		    is_multicast_ether_addr(sta->sta.addr)))
		return -EINVAL;

	return 0;
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.