wifi: mac80211: drop injection on disabled-chan monitor

If the driver uses the new IEEE80211_CHAN_CAN_MONITOR, we
may monitor on channels that are, e.g. via regulatory,
otherwise considered disabled. However, we really shouldn't
transmit on them, so prevent that.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240206164849.9c03dcf67dbe.Ib86a851c274c440908c663f6dd774b79bfc3965d@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/tx.c

@@ -5,7 +5,7 @@
  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
  * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
- * Copyright (C) 2018-2022 Intel Corporation
+ * Copyright (C) 2018-2024 Intel Corporation
  *
  * Transmit and frame generation functions.
  */
@@ -2393,6 +2393,14 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
 	else
 		goto fail_rcu;
 
+	/*
+	 * If driver/HW supports IEEE80211_CHAN_CAN_MONITOR we still
+	 * shouldn't transmit on disabled channels.
+	 */
+	if (!cfg80211_chandef_usable(local->hw.wiphy, chandef,
+				     IEEE80211_CHAN_DISABLED))
+		goto fail_rcu;
+
 	/*
 	 * Frame injection is not allowed if beaconing is not allowed
 	 * or if we need radar detection. Beaconing is usually not allowed when