mac80211: fix AP-mode frame matching

In AP mode, ignore frames with mis-matched BSSID that aren't
multicast or sent to the correct destination. This fixes
reporting public action frames to userspace multiple times
on multiple virtual AP interfaces.

Cc: stable@vger.kernel.org
Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/rx.c

@@ -3036,6 +3036,9 @@ static int prepare_for_handlers(struct ieee80211_rx_data *rx,
 			 * and location updates. Note that mac80211
 			 * itself never looks at these frames.
 			 */
+			if (!multicast &&
+			    !ether_addr_equal(sdata->vif.addr, hdr->addr1))
+				return 0;
 			if (ieee80211_is_public_action(hdr, skb->len))
 				return 1;
 			if (!ieee80211_is_beacon(hdr->frame_control))