}
 
 end:
-       if (status == WLAN_STATUS_SUCCESS)
+       if (status == WLAN_STATUS_SUCCESS) {
                __set_bit(tid, sta->ampdu_mlme.agg_session_valid);
+               __clear_bit(tid, sta->ampdu_mlme.unexpected_agg);
+       }
        mutex_unlock(&sta->ampdu_mlme.mtx);
 
 end_no_lock:
 
        tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
 
        tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
-       if (!tid_agg_rx)
+       if (!tid_agg_rx) {
+               if (ack_policy == IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
+                   !test_bit(tid, rx->sta->ampdu_mlme.agg_session_valid) &&
+                   !test_and_set_bit(tid, rx->sta->ampdu_mlme.unexpected_agg))
+                       ieee80211_send_delba(rx->sdata, rx->sta->sta.addr, tid,
+                                            WLAN_BACK_RECIPIENT,
+                                            WLAN_REASON_QSTA_REQUIRE_SETUP);
                goto dont_reorder;
+       }
 
        /* qos null data frames are excluded */
        if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
 
  * @tid_rx_stop_requested:  bitmap indicating which BA sessions per TID the
  *     driver requested to close until the work for it runs
  * @agg_session_valid: bitmap indicating which TID has a rx BA session open on
+ * @unexpected_agg: bitmap indicating which TID already sent a delBA due to
+ *     unexpected aggregation related frames outside a session
  * @work: work struct for starting/stopping aggregation
  * @tid_tx: aggregation info for Tx per TID
  * @tid_start_tx: sessions where start was requested
        unsigned long tid_rx_timer_expired[BITS_TO_LONGS(IEEE80211_NUM_TIDS)];
        unsigned long tid_rx_stop_requested[BITS_TO_LONGS(IEEE80211_NUM_TIDS)];
        unsigned long agg_session_valid[BITS_TO_LONGS(IEEE80211_NUM_TIDS)];
+       unsigned long unexpected_agg[BITS_TO_LONGS(IEEE80211_NUM_TIDS)];
        /* tx */
        struct work_struct work;
        struct tid_ampdu_tx __rcu *tid_tx[IEEE80211_NUM_TIDS];