From: Johannes Berg <johannes.berg@intel.com>
Date: Wed, 23 Jul 2025 07:14:19 +0000 (+0200)
Subject: wifi: mac80211: fix WARN_ON for monitor mode on some devices
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c57e5b9819dfd16d709bcd6cb633301ed0829a66;p=thirdparty%2Flinux.git

wifi: mac80211: fix WARN_ON for monitor mode on some devices

On devices without WANT_MONITOR_VIF (and probably without
channel context support) we get a WARN_ON for changing the
per-link setting of a monitor interface.

Since we already skip AP_VLAN interfaces and MONITOR with
WANT_MONITOR_VIF and/or NO_VIRTUAL_MONITOR should update
the settings, catch this in the link change code instead
of the warning.

Reported-by: Martin Kaistra <martin.kaistra@linutronix.de>
Link: https://lore.kernel.org/r/a9de62a0-28f1-4981-84df-253489da74ed@linutronix.de/
Fixes: c4382d5ca1af ("wifi: mac80211: update the right link for tx power")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 351564360c266..9c8f18b258a68 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -408,9 +408,20 @@ void ieee80211_link_info_change_notify(struct ieee80211_sub_if_data *sdata,
 
 	WARN_ON_ONCE(changed & BSS_CHANGED_VIF_CFG_FLAGS);
 
-	if (!changed || sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
+	if (!changed)
 		return;
 
+	switch (sdata->vif.type) {
+	case NL80211_IFTYPE_AP_VLAN:
+		return;
+	case NL80211_IFTYPE_MONITOR:
+		if (!ieee80211_hw_check(&local->hw, WANT_MONITOR_VIF))
+			return;
+		break;
+	default:
+		break;
+	}
+
 	if (!check_sdata_in_driver(sdata))
 		return;