package/kernel/mac80211/patches/subsys/520-nl80211-genetlink-hold-RCU-in-genlmsg_mcast.patch

--- a/backport-include/net/genetlink.h
+++ b/backport-include/net/genetlink.h
@@ -240,7 +240,7 @@ int genlmsg_multicast(const struct genl_
 #define genlmsg_multicast_allns LINUX_BACKPORT(genlmsg_multicast_allns)
 int backport_genlmsg_multicast_allns(const struct genl_family *family,
 				     struct sk_buff *skb, u32 portid,
-				     unsigned int group, gfp_t flags);
+				     unsigned int group);
 
 #define genl_family_attrbuf LINUX_BACKPORT(genl_family_attrbuf)
 static inline struct nlattr **genl_family_attrbuf(struct genl_family *family)
--- a/compat/backport-genetlink.c
+++ b/compat/backport-genetlink.c
@@ -397,23 +397,23 @@ int genlmsg_multicast(const struct genl_
 }
 EXPORT_SYMBOL_GPL(genlmsg_multicast);
 
-static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
-			 gfp_t flags)
+static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group)
 {
 	struct sk_buff *tmp;
 	struct net *net, *prev = NULL;
 	bool delivered = false;
 	int err;
 
+	rcu_read_lock();
 	for_each_net_rcu(net) {
 		if (prev) {
-			tmp = skb_clone(skb, flags);
+			tmp = skb_clone(skb, GFP_ATOMIC);
 			if (!tmp) {
 				err = -ENOMEM;
 				goto error;
 			}
 			err = nlmsg_multicast(prev->genl_sock, tmp,
-					      portid, group, flags);
+					      portid, group, GFP_ATOMIC);
 			if (!err)
 				delivered = true;
 			else if (err != -ESRCH)
@@ -422,25 +422,29 @@ static int genlmsg_mcast(struct sk_buff
 
 		prev = net;
 	}
+	err = nlmsg_multicast(prev->genl_sock, skb, portid, group, GFP_ATOMIC);
+
+	rcu_read_unlock();
 
-	err = nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
 	if (!err)
 		delivered = true;
 	else if (err != -ESRCH)
 		return err;
 	return delivered ? 0 : -ESRCH;
  error:
+	rcu_read_unlock();
+
 	kfree_skb(skb);
 	return err;
 }
 
 int backport_genlmsg_multicast_allns(const struct genl_family *family,
 				     struct sk_buff *skb, u32 portid,
-				     unsigned int group, gfp_t flags)
+				     unsigned int group)
 {
 	group = __backport_genl_group(family, group);
 	if (group == INVALID_GROUP)
 		return -EINVAL;
-	return genlmsg_mcast(skb, portid, group, flags);
+	return genlmsg_mcast(skb, portid, group);
 }
 EXPORT_SYMBOL_GPL(backport_genlmsg_multicast_allns);
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -16238,10 +16238,8 @@ void nl80211_common_reg_change_event(enu
 
 	genlmsg_end(msg, hdr);
 
-	rcu_read_lock();
 	genlmsg_multicast_allns(&nl80211_fam, msg, 0,
-				NL80211_MCGRP_REGULATORY, GFP_ATOMIC);
-	rcu_read_unlock();
+				NL80211_MCGRP_REGULATORY);
 
 	return;
 
@@ -16755,10 +16753,8 @@ void nl80211_send_beacon_hint_event(stru
 
 	genlmsg_end(msg, hdr);
 
-	rcu_read_lock();
 	genlmsg_multicast_allns(&nl80211_fam, msg, 0,
-				NL80211_MCGRP_REGULATORY, GFP_ATOMIC);
-	rcu_read_unlock();
+				NL80211_MCGRP_REGULATORY);
 
 	return;