wifi: mac80211: drop robust action frames before assoc

To be able to more easily understand the code, drop robust
action frames before being associated, even if there's no
MFP in the end, as they are Class 3 Frames and shouldn't
be transmitted in the first place.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20231001125722.b2fd37083371.Ie9f4906e2f6c698989bce6681956ed2f9454f27c@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/rx.c

@@ -2474,6 +2474,15 @@ ieee80211_drop_unencrypted_mgmt(struct ieee80211_rx_data *rx)
 			return RX_DROP_U_UNPROT_UNICAST_PUB_ACTION;
 	}
 
+	/*
+	 * Drop robust action frames before assoc regardless of MFP state,
+	 * after assoc we also have decided on MFP or not.
+	 */
+	if (ieee80211_is_action(fc) &&
+	    ieee80211_is_robust_mgmt_frame(rx->skb) &&
+	    (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))
+		return RX_DROP_U_UNPROT_ROBUST_ACTION;
+
 	return RX_CONTINUE;
 }