Merge tag 'mac80211-for-net-2021-10-27' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
Two fixes:
 * bridge vs. 4-addr mode check was wrong
 * management frame registrations locking was
   wrong, causing list corruption/crashes
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: kuba-moo

include/net/cfg80211.h

@@ -5376,7 +5376,6 @@ static inline void wiphy_unlock(struct wiphy *wiphy)
  *	netdev and may otherwise be used by driver read-only, will be update
  *	by cfg80211 on change_interface
  * @mgmt_registrations: list of registrations for management frames
- * @mgmt_registrations_lock: lock for the list
  * @mgmt_registrations_need_update: mgmt registrations were updated,
  *	need to propagate the update to the driver
  * @mtx: mutex used to lock data in this struct, may be used by drivers
@@ -5423,7 +5422,6 @@ struct wireless_dev {
 	u32 identifier;
 
 	struct list_head mgmt_registrations;
-	spinlock_t mgmt_registrations_lock;
 	u8 mgmt_registrations_need_update:1;
 
 	struct mutex mtx;

net/wireless/core.c

@@ -524,6 +524,7 @@ struct wiphy *wiphy_new_nm(const struct cfg80211_ops *ops, int sizeof_priv,
 	INIT_WORK(&rdev->propagate_cac_done_wk, cfg80211_propagate_cac_done_wk);
 	INIT_WORK(&rdev->mgmt_registrations_update_wk,
 		  cfg80211_mgmt_registrations_update_wk);
+	spin_lock_init(&rdev->mgmt_registrations_lock);
 
 #ifdef CONFIG_CFG80211_DEFAULT_PS
 	rdev->wiphy.flags |= WIPHY_FLAG_PS_ON_BY_DEFAULT;
@@ -1279,7 +1280,6 @@ void cfg80211_init_wdev(struct wireless_dev *wdev)
 	INIT_LIST_HEAD(&wdev->event_list);
 	spin_lock_init(&wdev->event_lock);
 	INIT_LIST_HEAD(&wdev->mgmt_registrations);
-	spin_lock_init(&wdev->mgmt_registrations_lock);
 	INIT_LIST_HEAD(&wdev->pmsr_list);
 	spin_lock_init(&wdev->pmsr_lock);
 	INIT_WORK(&wdev->pmsr_free_wk, cfg80211_pmsr_free_wk);

net/wireless/core.h

@@ -100,6 +100,8 @@ struct cfg80211_registered_device {
 	struct work_struct propagate_cac_done_wk;
 
 	struct work_struct mgmt_registrations_update_wk;
+	/* lock for all wdev lists */
+	spinlock_t mgmt_registrations_lock;
 
 	/* must be last because of the way we do wiphy_priv(),
 	 * and it should at least be aligned to NETDEV_ALIGN */

net/wireless/mlme.c

@@ -452,9 +452,9 @@ static void cfg80211_mgmt_registrations_update(struct wireless_dev *wdev)
 
 	lockdep_assert_held(&rdev->wiphy.mtx);
 
-	spin_lock_bh(&wdev->mgmt_registrations_lock);
+	spin_lock_bh(&rdev->mgmt_registrations_lock);
 	if (!wdev->mgmt_registrations_need_update) {
-		spin_unlock_bh(&wdev->mgmt_registrations_lock);
+		spin_unlock_bh(&rdev->mgmt_registrations_lock);
 		return;
 	}
 
@@ -479,7 +479,7 @@ static void cfg80211_mgmt_registrations_update(struct wireless_dev *wdev)
 	rcu_read_unlock();
 
 	wdev->mgmt_registrations_need_update = 0;
-	spin_unlock_bh(&wdev->mgmt_registrations_lock);
+	spin_unlock_bh(&rdev->mgmt_registrations_lock);
 
 	rdev_update_mgmt_frame_registrations(rdev, wdev, &upd);
 }
@@ -503,6 +503,7 @@ int cfg80211_mlme_register_mgmt(struct wireless_dev *wdev, u32 snd_portid,
 				int match_len, bool multicast_rx,
 				struct netlink_ext_ack *extack)
 {
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
 	struct cfg80211_mgmt_registration *reg, *nreg;
 	int err = 0;
 	u16 mgmt_type;
@@ -548,7 +549,7 @@ int cfg80211_mlme_register_mgmt(struct wireless_dev *wdev, u32 snd_portid,
 	if (!nreg)
 		return -ENOMEM;
 
-	spin_lock_bh(&wdev->mgmt_registrations_lock);
+	spin_lock_bh(&rdev->mgmt_registrations_lock);
 
 	list_for_each_entry(reg, &wdev->mgmt_registrations, list) {
 		int mlen = min(match_len, reg->match_len);
@@ -583,15 +584,15 @@ int cfg80211_mlme_register_mgmt(struct wireless_dev *wdev, u32 snd_portid,
 		list_add(&nreg->list, &wdev->mgmt_registrations);
 	}
 	wdev->mgmt_registrations_need_update = 1;
-	spin_unlock_bh(&wdev->mgmt_registrations_lock);
+	spin_unlock_bh(&rdev->mgmt_registrations_lock);
 
 	cfg80211_mgmt_registrations_update(wdev);
 
 	return 0;
 
  out:
 	kfree(nreg);
-	spin_unlock_bh(&wdev->mgmt_registrations_lock);
+	spin_unlock_bh(&rdev->mgmt_registrations_lock);
 
 	return err;
 }
@@ -602,7 +603,7 @@ void cfg80211_mlme_unregister_socket(struct wireless_dev *wdev, u32 nlportid)
 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 	struct cfg80211_mgmt_registration *reg, *tmp;
 
-	spin_lock_bh(&wdev->mgmt_registrations_lock);
+	spin_lock_bh(&rdev->mgmt_registrations_lock);
 
 	list_for_each_entry_safe(reg, tmp, &wdev->mgmt_registrations, list) {
 		if (reg->nlportid != nlportid)
@@ -615,7 +616,7 @@ void cfg80211_mlme_unregister_socket(struct wireless_dev *wdev, u32 nlportid)
 		schedule_work(&rdev->mgmt_registrations_update_wk);
 	}
 
-	spin_unlock_bh(&wdev->mgmt_registrations_lock);
+	spin_unlock_bh(&rdev->mgmt_registrations_lock);
 
 	if (nlportid && rdev->crit_proto_nlportid == nlportid) {
 		rdev->crit_proto_nlportid = 0;
@@ -628,15 +629,16 @@ void cfg80211_mlme_unregister_socket(struct wireless_dev *wdev, u32 nlportid)
 
 void cfg80211_mlme_purge_registrations(struct wireless_dev *wdev)
 {
+	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
 	struct cfg80211_mgmt_registration *reg, *tmp;
 
-	spin_lock_bh(&wdev->mgmt_registrations_lock);
+	spin_lock_bh(&rdev->mgmt_registrations_lock);
 	list_for_each_entry_safe(reg, tmp, &wdev->mgmt_registrations, list) {
 		list_del(&reg->list);
 		kfree(reg);
 	}
 	wdev->mgmt_registrations_need_update = 1;
-	spin_unlock_bh(&wdev->mgmt_registrations_lock);
+	spin_unlock_bh(&rdev->mgmt_registrations_lock);
 
 	cfg80211_mgmt_registrations_update(wdev);
 }
@@ -784,7 +786,7 @@ bool cfg80211_rx_mgmt_khz(struct wireless_dev *wdev, int freq, int sig_dbm,
 	data = buf + ieee80211_hdrlen(mgmt->frame_control);
 	data_len = len - ieee80211_hdrlen(mgmt->frame_control);
 
-	spin_lock_bh(&wdev->mgmt_registrations_lock);
+	spin_lock_bh(&rdev->mgmt_registrations_lock);
 
 	list_for_each_entry(reg, &wdev->mgmt_registrations, list) {
 		if (reg->frame_type != ftype)
@@ -808,7 +810,7 @@ bool cfg80211_rx_mgmt_khz(struct wireless_dev *wdev, int freq, int sig_dbm,
 		break;
 	}
 
-	spin_unlock_bh(&wdev->mgmt_registrations_lock);
+	spin_unlock_bh(&rdev->mgmt_registrations_lock);
 
 	trace_cfg80211_return_bool(result);
 	return result;

net/wireless/util.c

@@ -1028,14 +1028,14 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
 	    !(rdev->wiphy.interface_modes & (1 << ntype)))
 		return -EOPNOTSUPP;
 
-	/* if it's part of a bridge, reject changing type to station/ibss */
-	if (netif_is_bridge_port(dev) &&
-	    (ntype == NL80211_IFTYPE_ADHOC ||
-	     ntype == NL80211_IFTYPE_STATION ||
-	     ntype == NL80211_IFTYPE_P2P_CLIENT))
-		return -EBUSY;
-
 	if (ntype != otype) {
+		/* if it's part of a bridge, reject changing type to station/ibss */
+		if (netif_is_bridge_port(dev) &&
+		    (ntype == NL80211_IFTYPE_ADHOC ||
+		     ntype == NL80211_IFTYPE_STATION ||
+		     ntype == NL80211_IFTYPE_P2P_CLIENT))
+			return -EBUSY;
+
 		dev->ieee80211_ptr->use_4addr = false;
 		dev->ieee80211_ptr->mesh_id_up_len = 0;
 		wdev_lock(dev->ieee80211_ptr);