[nrf fromtree] net: l2: wifi: Protect processing of nm data

Use lock while accessing nm data.
One of the use case is while setting regulatory, it accesses nm data,
while from some other place also it can be accessed same time.
Protected the nm data processing.

Signed-off-by: Ajay Parida <[email protected]>
(cherry picked from commit b930026)

Author: ajayparida

subsys/net/l2/wifi/wifi_nm.c

@@ -10,6 +10,9 @@ LOG_MODULE_REGISTER(wifi_nm, CONFIG_WIFI_NM_LOG_LEVEL);
 #include <zephyr/kernel.h>
 #include <zephyr/net/wifi_nm.h>
 
+/* Used to protect nm data */
+static K_MUTEX_DEFINE(wifi_nm_lock);
+
 struct wifi_nm_instance *wifi_nm_get_instance(const char *name)
 {
 	STRUCT_SECTION_FOREACH(wifi_nm_instance, nm) {
@@ -27,13 +30,16 @@ struct wifi_nm_instance *wifi_nm_get_instance_iface(struct net_if *iface)
 		return false;
 	}
 
+	k_mutex_lock(&wifi_nm_lock, K_FOREVER);
 	STRUCT_SECTION_FOREACH(wifi_nm_instance, nm) {
 		for (int i = 0; i < CONFIG_WIFI_NM_MAX_MANAGED_INTERFACES; i++) {
 			if (nm->mgd_ifaces[i] == iface) {
+				k_mutex_unlock(&wifi_nm_lock);
 				return nm;
 			}
 		}
 	}
+	k_mutex_unlock(&wifi_nm_lock);
 
 	return NULL;
 }
@@ -48,12 +54,15 @@ int wifi_nm_register_mgd_iface(struct wifi_nm_instance *nm, struct net_if *iface
 		return -ENOTSUP;
 	}
 
+	k_mutex_lock(&wifi_nm_lock, K_FOREVER);
 	for (int i = 0; i < CONFIG_WIFI_NM_MAX_MANAGED_INTERFACES; i++) {
 		if (!nm->mgd_ifaces[i]) {
 			nm->mgd_ifaces[i] = iface;
+			k_mutex_unlock(&wifi_nm_lock);
 			return 0;
 		}
 	}
+	k_mutex_unlock(&wifi_nm_lock);
 
 	return -ENOMEM;
 }
@@ -64,12 +73,15 @@ int wifi_nm_unregister_mgd_iface(struct wifi_nm_instance *nm, struct net_if *ifa
 		return -EINVAL;
 	}
 
+	k_mutex_lock(&wifi_nm_lock, K_FOREVER);
 	for (int i = 0; i < CONFIG_WIFI_NM_MAX_MANAGED_INTERFACES; i++) {
 		if (nm->mgd_ifaces[i] == iface) {
 			nm->mgd_ifaces[i] = NULL;
+			k_mutex_unlock(&wifi_nm_lock);
 			return 0;
 		}
 	}
+	k_mutex_unlock(&wifi_nm_lock);
 
 	return -ENOENT;
 }