wifi: mac80211: drop unprotected robust mgmt before 4-way-HS

When MFP is used, drop unprotected robust management frames also
before the 4-way handshake has been completed, i.e. no key has
been installed yet.

Signed-off-by: Alon Giladi <alon.giladi@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230619183718.cfbefddccd0c.Ife369dbb61c87e311ce15739d5b2b4763bfdfbae@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/rx.c

@@ -2418,13 +2418,20 @@ static int ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
 
 	if (rx->sta && test_sta_flag(rx->sta, WLAN_STA_MFP)) {
 		if (unlikely(!ieee80211_has_protected(fc) &&
-			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb) &&
-			     rx->key)) {
+			     ieee80211_is_unicast_robust_mgmt_frame(rx->skb))) {
 			if (ieee80211_is_deauth(fc) ||
-			    ieee80211_is_disassoc(fc))
+			    ieee80211_is_disassoc(fc)) {
+				/*
+				 * Permit unprotected deauth/disassoc frames
+				 * during 4-way-HS (key is installed after HS).
+				 */
+				if (!rx->key)
+					return 0;
+
 				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
 							     rx->skb->data,
 							     rx->skb->len);
+			}
 			return -EACCES;
 		}
 		/* BIP does not use Protected field, so need to check MMIE */