diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 2fe18dc6af86..6b4fd56800f7 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2003,6 +2003,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 	unsigned int frag, seq;
 	struct ieee80211_fragment_entry *entry;
 	struct sk_buff *skb;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 
 	hdr = (struct ieee80211_hdr *)rx->skb->data;
 	fc = hdr->frame_control;
@@ -2061,7 +2062,9 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 				     sizeof(rx->key->u.gcmp.rx_pn[queue]));
 			BUILD_BUG_ON(IEEE80211_CCMP_PN_LEN !=
 				     IEEE80211_GCMP_PN_LEN);
-		} else if (rx->key && ieee80211_has_protected(fc)) {
+		} else if (rx->key &&
+			   (ieee80211_has_protected(fc) ||
+			    (status->flag & RX_FLAG_DECRYPTED))) {
 			entry->is_protected = true;
 			entry->key_color = rx->key->color;
 		}
@@ -2106,13 +2109,19 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 			return RX_DROP_UNUSABLE;
 		memcpy(entry->last_pn, pn, IEEE80211_CCMP_PN_LEN);
 	} else if (entry->is_protected &&
-		   (!rx->key || !ieee80211_has_protected(fc) ||
+		   (!rx->key ||
+		    (!ieee80211_has_protected(fc) &&
+		     !(status->flag & RX_FLAG_DECRYPTED)) ||
 		    rx->key->color != entry->key_color)) {
 		/* Drop this as a mixed key or fragment cache attack, even
 		 * if for TKIP Michael MIC should protect us, and WEP is a
 		 * lost cause anyway.
 		 */
 		return RX_DROP_UNUSABLE;
+	} else if (entry->is_protected && rx->key &&
+		   entry->key_color != rx->key->color &&
+		   (status->flag & RX_FLAG_DECRYPTED)) {
+		return RX_DROP_UNUSABLE;
 	}
 
 	skb_pull(rx->skb, ieee80211_hdrlen(fc));