mac80211: Check port authorization in the ieee80211_tx_dequeue() case

mac80211 used to check port authorization in the Data frame enqueue case
when going through start_xmit(). However, that authorization status may
change while the frame is waiting in a queue. Add a similar check in the
dequeue case to avoid sending previously accepted frames after
authorization change. This provides additional protection against
potential leaking of frames after a station has been disconnected and
the keys for it are being removed.

Cc: stable@vger.kernel.org
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Link: https://lore.kernel.org/r/20200326155133.ced84317ea29.I34d4c47cd8cc8a4042b38a76f16a601fbcbfd9b3@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 7dbfb9e..455eb8e 100644 (file)
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -3604,8 +3604,25 @@ begin:
        tx.skb = skb;
        tx.sdata = vif_to_sdata(info->control.vif);
 
-       if (txq->sta)
+       if (txq->sta) {
                tx.sta = container_of(txq->sta, struct sta_info, sta);
+               /*
+                * Drop unicast frames to unauthorised stations unless they are
+                * EAPOL frames from the local station.
+                */
+               if (unlikely(!ieee80211_vif_is_mesh(&tx.sdata->vif) &&
+                            tx.sdata->vif.type != NL80211_IFTYPE_OCB &&
+                            !is_multicast_ether_addr(hdr->addr1) &&
+                            !test_sta_flag(tx.sta, WLAN_STA_AUTHORIZED) &&
+                            (!(info->control.flags &
+                               IEEE80211_TX_CTRL_PORT_CTRL_PROTO) ||
+                             !ether_addr_equal(tx.sdata->vif.addr,
+                                               hdr->addr2)))) {
+                       I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
+                       ieee80211_free_txskb(&local->hw, skb);
+                       goto begin;
+               }
+       }
 
        /*
         * The key can be removed while the packet was queued, so need to call