wifi: cfg80211: check RTNL when iterating devices

Add a new "for_each_rdev()" macro and check that we
hold the RTNL when calling it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/chan.c

@@ -823,7 +823,7 @@ bool cfg80211_any_wiphy_oper_chan(struct wiphy *wiphy,
 	if (!(chan->flags & IEEE80211_CHAN_RADAR))
 		return false;
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		if (!reg_dfs_domain_same(wiphy, &rdev->wiphy))
 			continue;
 

net/wireless/core.c

@@ -60,7 +60,7 @@ struct cfg80211_registered_device *cfg80211_rdev_by_wiphy_idx(int wiphy_idx)
 
 	ASSERT_RTNL();
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		if (rdev->wiphy_idx == wiphy_idx) {
 			result = rdev;
 			break;
@@ -116,7 +116,7 @@ static int cfg80211_dev_check_name(struct cfg80211_registered_device *rdev,
 	}
 
 	/* Ensure another device does not already have this name. */
-	list_for_each_entry(rdev2, &cfg80211_rdev_list, list)
+	for_each_rdev(rdev2)
 		if (strcmp(newname, wiphy_name(&rdev2->wiphy)) == 0)
 			return -EINVAL;
 
@@ -1601,7 +1601,7 @@ static void __net_exit cfg80211_pernet_exit(struct net *net)
 	struct cfg80211_registered_device *rdev;
 
 	rtnl_lock();
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		if (net_eq(wiphy_net(&rdev->wiphy), net))
 			WARN_ON(cfg80211_switch_netns(rdev, &init_net));
 	}

net/wireless/core.h

@@ -160,6 +160,16 @@ extern struct workqueue_struct *cfg80211_wq;
 extern struct list_head cfg80211_rdev_list;
 extern int cfg80211_rdev_list_generation;
 
+/* This is constructed like this so it can be used in if/else */
+static inline int for_each_rdev_check_rtnl(void)
+{
+	ASSERT_RTNL();
+	return 0;
+}
+#define for_each_rdev(rdev)						\
+	if (for_each_rdev_check_rtnl()) {} else				\
+		list_for_each_entry(rdev, &cfg80211_rdev_list, list)
+
 struct cfg80211_internal_bss {
 	struct list_head list;
 	struct list_head hidden_list;

net/wireless/nl80211.c

@@ -106,7 +106,7 @@ __cfg80211_wdev_from_attrs(struct cfg80211_registered_device *rdev,
 
 	ASSERT_RTNL();
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		struct wireless_dev *wdev;
 
 		if (wiphy_net(&rdev->wiphy) != netns)
@@ -3075,7 +3075,7 @@ static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
 		cb->args[0] = (long)state;
 	}
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		if (!net_eq(wiphy_net(&rdev->wiphy), sock_net(skb->sk)))
 			continue;
 		if (++idx <= state->start)
@@ -3985,7 +3985,7 @@ static int nl80211_dump_interface(struct sk_buff *skb, struct netlink_callback *
 		filter_wiphy = cb->args[2] - 1;
 	}
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		if (!net_eq(wiphy_net(&rdev->wiphy), sock_net(skb->sk)))
 			continue;
 		if (wp_idx < wp_start) {

net/wireless/reg.c

@@ -2461,7 +2461,7 @@ static void reg_check_chans_work(struct work_struct *work)
 	pr_debug("Verifying active interfaces after reg change\n");
 	rtnl_lock();
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list)
+	for_each_rdev(rdev)
 		reg_leave_invalid_chans(&rdev->wiphy);
 
 	rtnl_unlock();
@@ -2515,7 +2515,7 @@ static void update_all_wiphy_regulatory(enum nl80211_reg_initiator initiator)
 
 	ASSERT_RTNL();
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		wiphy = &rdev->wiphy;
 		wiphy_update_regulatory(wiphy, initiator);
 	}
@@ -2991,7 +2991,7 @@ static void wiphy_all_share_dfs_chan_state(struct wiphy *wiphy)
 
 	ASSERT_RTNL();
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		if (wiphy == &rdev->wiphy)
 			continue;
 		wiphy_share_dfs_chan_state(wiphy, &rdev->wiphy);
@@ -3057,7 +3057,7 @@ static void notify_self_managed_wiphys(struct regulatory_request *request)
 	struct cfg80211_registered_device *rdev;
 	struct wiphy *wiphy;
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		wiphy = &rdev->wiphy;
 		if (wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED &&
 		    request->initiator == NL80211_REGDOM_SET_BY_USER)
@@ -3122,7 +3122,7 @@ static void reg_process_pending_beacon_hints(void)
 		list_del_init(&pending_beacon->list);
 
 		/* Applies the beacon hint to current wiphys */
-		list_for_each_entry(rdev, &cfg80211_rdev_list, list)
+		for_each_rdev(rdev)
 			wiphy_update_new_beacon(&rdev->wiphy, pending_beacon);
 
 		/* Remembers the beacon hint for new wiphys or reg changes */
@@ -3177,7 +3177,7 @@ static void reg_process_self_managed_hints(void)
 
 	ASSERT_RTNL();
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		wiphy_lock(&rdev->wiphy);
 		reg_process_self_managed_hint(&rdev->wiphy);
 		wiphy_unlock(&rdev->wiphy);
@@ -3517,7 +3517,7 @@ static void restore_regulatory_settings(bool reset_user, bool cached)
 	world_alpha2[0] = cfg80211_world_regdom->alpha2[0];
 	world_alpha2[1] = cfg80211_world_regdom->alpha2[1];
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		if (rdev->wiphy.regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED)
 			continue;
 		if (rdev->wiphy.regulatory_flags & REGULATORY_CUSTOM_REG)
@@ -3574,7 +3574,7 @@ static bool is_wiphy_all_set_reg_flag(enum ieee80211_regulatory_flags flag)
 	struct cfg80211_registered_device *rdev;
 	struct wireless_dev *wdev;
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 			wdev_lock(wdev);
 			if (!(wdev->wiphy->regulatory_flags & flag)) {
@@ -4244,7 +4244,7 @@ void regulatory_propagate_dfs_state(struct wiphy *wiphy,
 	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
 		return;
 
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		if (wiphy == &rdev->wiphy)
 			continue;
 

net/wireless/sme.c

@@ -702,7 +702,7 @@ static bool cfg80211_is_all_idle(void)
 	 * need not issue a disconnect hint and reset any info such
 	 * as chan dfs state, etc.
 	 */
-	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
+	for_each_rdev(rdev) {
 		list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 			wdev_lock(wdev);
 			if (wdev->conn || wdev->connected ||