diff --git a/src/common/linked_list.c b/src/common/linked_list.c
index c3f8720b..d0ac6162 100644
--- a/src/common/linked_list.c
+++ b/src/common/linked_list.c
@@ -156,14 +156,14 @@ LinkedList_remove(LinkedList list, void* data)
 LinkedList
 LinkedList_insertAfter(LinkedList list, void* data)
 {
-    LinkedList originalNextElement = LinkedList_getNext(list);
-
     LinkedList newElement = LinkedList_create();
 
-    newElement->data = data;
-    newElement->next = originalNextElement;
+    if (newElement) {
+        newElement->data = data;
+        newElement->next = LinkedList_getNext(list);
 
-    list->next = newElement;
+        list->next = newElement;
+    }
 
     return newElement;
 }
diff --git a/src/mms/iso_mms/server/mms_file_service.c b/src/mms/iso_mms/server/mms_file_service.c
index ab86c880..fce656cc 100644
--- a/src/mms/iso_mms/server/mms_file_service.c
+++ b/src/mms/iso_mms/server/mms_file_service.c
@@ -1,7 +1,7 @@
 /*
  *  mms_file_service.c
  *
- *  Copyright 2013-2018 Michael Zillgith
+ *  Copyright 2013-2022 Michael Zillgith
  *
  *  This file is part of libIEC61850.
  *
@@ -370,7 +370,6 @@ mmsServer_handleFileOpenRequest(
             else
                 mmsMsg_createServiceErrorPdu(invokeId, response, MMS_ERROR_FILE_FILE_NON_EXISTENT);
 
-
         }
         else
             mmsMsg_createServiceErrorPdu(invokeId, response, MMS_ERROR_RESOURCE_OTHER);
@@ -390,7 +389,6 @@ exit_reject_invalid_pdu:
 
 #if (MMS_OBTAIN_FILE_SERVICE == 1)
 
-
 static void /* Confirmed service error (ServiceError) */
 createServiceErrorObtainFileError(uint32_t invokeId, ByteBuffer* response,
         MmsError errorType, uint32_t value)
@@ -403,7 +401,6 @@ createServiceErrorObtainFileError(uint32_t invokeId, ByteBuffer* response,
             buffer, size);
 }
 
-
 static void
 createObtainFileResponse(uint32_t invokeId, ByteBuffer* response)
 {
@@ -1176,7 +1173,8 @@ mmsServer_handleFileDirectoryRequest(
 
     char* continueAfter = NULL;
 
-    while (bufPos < maxBufPos) {
+    while (bufPos < maxBufPos)
+    {
         uint8_t tag = buffer[bufPos++];
         int length;
 
@@ -1215,8 +1213,6 @@ mmsServer_handleFileDirectoryRequest(
             mmsMsg_createMmsRejectPdu(&invokeId, MMS_ERROR_REJECT_INVALID_PDU, response);
             return;
         }
-
-
     }
 
     int maxPduSize = connection->maxPduSize;
diff --git a/src/mms/iso_mms/server/mms_get_namelist_service.c b/src/mms/iso_mms/server/mms_get_namelist_service.c
index 77c13d5c..f1a24b6a 100644
--- a/src/mms/iso_mms/server/mms_get_namelist_service.c
+++ b/src/mms/iso_mms/server/mms_get_namelist_service.c
@@ -1,7 +1,7 @@
 /*
  *  mms_get_namelist_service.c
  *
- *  Copyright 2013, 2014, 2015 Michael Zillgith
+ *  Copyright 2013-2022 Michael Zillgith
  *
  *  This file is part of libIEC61850.
  *
@@ -109,18 +109,21 @@ appendMmsSubVariable(char* name, char* child)
 
     char* newName = (char*) GLOBAL_MALLOC(newSize);
 
-    int bufPos = 0;
-    int i;
-    for (i = 0; i < nameLen; i++) {
-        newName[bufPos++] = name[i];
-    }
-    newName[bufPos++] = '$';
+    if (newName)
+    {
+        int bufPos = 0;
+        int i;
+        for (i = 0; i < nameLen; i++) {
+            newName[bufPos++] = name[i];
+        }
+        newName[bufPos++] = '$';
 
-    for (i = 0; i < childLen; i++) {
-        newName[bufPos++] = child[i];
-    }
+        for (i = 0; i < childLen; i++) {
+            newName[bufPos++] = child[i];
+        }
 
-    newName[bufPos] = 0;
+        newName[bufPos] = 0;
+    }
 
     return newName;
 }
@@ -139,30 +142,37 @@ addSubNamedVaribleNamesToList(LinkedList nameList, char* prefix, MmsVariableSpec
 #if (CONFIG_MMS_SORT_NAME_LIST == 1)
         int* index = (int*) GLOBAL_MALLOC(sizeof(int) * variable->typeSpec.structure.elementCount);
 
-        for (i = 0; i < variable->typeSpec.structure.elementCount; i++)
-            index[i] = i;
+        if (index)
+        {
+            for (i = 0; i < variable->typeSpec.structure.elementCount; i++)
+                index[i] = i;
 
-        sortIndex(index, variable->typeSpec.structure.elementCount, variables);
+            sortIndex(index, variable->typeSpec.structure.elementCount, variables);
 #endif /* (CONFIG_MMS_SORT_NAME_LIST == 1) */
 
-        for (i = 0; i < variable->typeSpec.structure.elementCount; i++) {
+            for (i = 0; i < variable->typeSpec.structure.elementCount; i++) {
 #if (CONFIG_MMS_SORT_NAME_LIST == 1)
-            char* variableName = appendMmsSubVariable(prefix, variables[index[i]]->name);
+                char* variableName = appendMmsSubVariable(prefix, variables[index[i]]->name);
 #else
-            char* variableName = appendMmsSubVariable(prefix, variables[i]->name);
+                char* variableName = appendMmsSubVariable(prefix, variables[i]->name);
 #endif /* (CONFIG_MMS_SORT_NAME_LIST == 1) */
 
-            listElement = LinkedList_insertAfter(listElement, variableName);
+                if (variableName)
+                {
+                    listElement = LinkedList_insertAfter(listElement, variableName);
 
 #if (CONFIG_MMS_SORT_NAME_LIST == 1)
-            listElement = addSubNamedVaribleNamesToList(listElement, variableName, variables[index[i]]);
+                    listElement = addSubNamedVaribleNamesToList(listElement, variableName, variables[index[i]]);
 #else
-            listElement = addSubNamedVaribleNamesToList(listElement, variableName, variables[i]);
+                    listElement = addSubNamedVaribleNamesToList(listElement, variableName, variables[i]);
 #endif /* (CONFIG_MMS_SORT_NAME_LIST == 1) */
-        }
+                }
+            }
 
 #if (CONFIG_MMS_SORT_NAME_LIST == 1)
-        GLOBAL_FREEMEM(index);
+            GLOBAL_FREEMEM(index);
+
+        }
 #endif
     }