diff --git a/components/connectivity/qcloud-iot-explorer-sdk/3rdparty/sdk_src/utils/json_token.c b/components/connectivity/qcloud-iot-explorer-sdk/3rdparty/sdk_src/utils/json_token.c
index 97d72cdc..9e760f88 100644
--- a/components/connectivity/qcloud-iot-explorer-sdk/3rdparty/sdk_src/utils/json_token.c
+++ b/components/connectivity/qcloud-iot-explorer-sdk/3rdparty/sdk_src/utils/json_token.c
@@ -91,6 +91,9 @@ list_head_t *LITE_json_keys_of(char *src, char *prefix)
             json_key_t     *entry = NULL;
 
             entry = HAL_Malloc(sizeof(json_key_t));
+            if (NULL == entry) {
+                return NULL;
+            }
             memset(entry, 0, sizeof(json_key_t));
             entry->key = LITE_format_string("%s%.*s", prefix, klen, key);
             list_add_tail(&entry->list, &keylist);
@@ -109,6 +112,9 @@ list_head_t *LITE_json_keys_of(char *src, char *prefix)
         json_key_t     *entry = NULL;
 
         entry = HAL_Malloc(sizeof(json_key_t));
+        if (NULL == entry) {
+            return NULL;
+        }
         memset(entry, 0, sizeof(json_key_t));
         list_add_tail(&entry->list, &keylist);
 
diff --git a/components/connectivity/qcloud-iot-explorer-sdk/3rdparty/sdk_src/utils/string_utils.c b/components/connectivity/qcloud-iot-explorer-sdk/3rdparty/sdk_src/utils/string_utils.c
index e0755a2d..49e9763c 100644
--- a/components/connectivity/qcloud-iot-explorer-sdk/3rdparty/sdk_src/utils/string_utils.c
+++ b/components/connectivity/qcloud-iot-explorer-sdk/3rdparty/sdk_src/utils/string_utils.c
@@ -35,6 +35,9 @@ char *LITE_format_string(const char *fmt, ...)
 
     va_start(ap, fmt);
     tmp = HAL_Malloc(TEMP_STRING_MAXLEN);
+    if (NULL == tmp) {
+        return NULL;
+    }
     memset(tmp, 0, TEMP_STRING_MAXLEN);
     rc = HAL_Vsnprintf(tmp, TEMP_STRING_MAXLEN, fmt, ap);
     va_end(ap);
@@ -58,6 +61,9 @@ char *LITE_format_nstring(const int len, const char *fmt, ...)
 
     va_start(ap, fmt);
     tmp = HAL_Malloc(len+2);
+    if (NULL == tmp) {
+        return NULL;
+    }
     memset(tmp, 0, len+2);
     rc = HAL_Vsnprintf(tmp, len+1, fmt, ap);
     va_end(ap);
diff --git a/components/connectivity/qcloud-iot-hub-sdk-3.1.2/3rdparty/sdk_src/utils/json_token.c b/components/connectivity/qcloud-iot-hub-sdk-3.1.2/3rdparty/sdk_src/utils/json_token.c
index 8c51cb9f..411d78bb 100644
--- a/components/connectivity/qcloud-iot-hub-sdk-3.1.2/3rdparty/sdk_src/utils/json_token.c
+++ b/components/connectivity/qcloud-iot-hub-sdk-3.1.2/3rdparty/sdk_src/utils/json_token.c
@@ -99,6 +99,9 @@ list_head_t *LITE_json_keys_of(char *src, char *prefix)
             json_key_t     *entry = NULL;
 
             entry = HAL_Malloc(sizeof(json_key_t));
+            if (NULL == entry) {
+                return NULL;
+            }
             memset(entry, 0, sizeof(json_key_t));
             entry->key = LITE_format_string("%s%.*s", prefix, klen, key);
             list_add_tail(&entry->list, &keylist);
@@ -117,6 +120,9 @@ list_head_t *LITE_json_keys_of(char *src, char *prefix)
         json_key_t     *entry = NULL;
 
         entry = HAL_Malloc(sizeof(json_key_t));
+        if (NULL == entry) {
+            return NULL;
+        }
         memset(entry, 0, sizeof(json_key_t));
         list_add_tail(&entry->list, &keylist);
 
diff --git a/components/connectivity/qcloud-iot-hub-sdk-3.1.2/3rdparty/sdk_src/utils/string_utils.c b/components/connectivity/qcloud-iot-hub-sdk-3.1.2/3rdparty/sdk_src/utils/string_utils.c
index e0755a2d..49e9763c 100644
--- a/components/connectivity/qcloud-iot-hub-sdk-3.1.2/3rdparty/sdk_src/utils/string_utils.c
+++ b/components/connectivity/qcloud-iot-hub-sdk-3.1.2/3rdparty/sdk_src/utils/string_utils.c
@@ -35,6 +35,9 @@ char *LITE_format_string(const char *fmt, ...)
 
     va_start(ap, fmt);
     tmp = HAL_Malloc(TEMP_STRING_MAXLEN);
+    if (NULL == tmp) {
+        return NULL;
+    }
     memset(tmp, 0, TEMP_STRING_MAXLEN);
     rc = HAL_Vsnprintf(tmp, TEMP_STRING_MAXLEN, fmt, ap);
     va_end(ap);
@@ -58,6 +61,9 @@ char *LITE_format_nstring(const int len, const char *fmt, ...)
 
     va_start(ap, fmt);
     tmp = HAL_Malloc(len+2);
+    if (NULL == tmp) {
+        return NULL;
+    }
     memset(tmp, 0, len+2);
     rc = HAL_Vsnprintf(tmp, len+1, fmt, ap);
     va_end(ap);