diff --git a/reactos/base/system/services/rpcserver.c b/reactos/base/system/services/rpcserver.c
index bfb7d8d7c70..4c877d27b00 100644
--- a/reactos/base/system/services/rpcserver.c
+++ b/reactos/base/system/services/rpcserver.c
@@ -2764,7 +2764,7 @@ DWORD RQueryServiceConfigW(
         lpStr += (wcslen(lpStr) + 1);
 
         /* Append the group name */
-        if (lpService->lpGroup != NULL)
+        if ((lpService->lpGroup != NULL) && (lpService->lpGroup->lpGroupName != NULL))
         {
             wcscpy(lpStr, lpService->lpGroup->lpGroupName);
         }
@@ -3733,6 +3733,11 @@ DWORD REnumServicesStatusA(
 
     DPRINT("REnumServicesStatusA() called\n");
 
+    if (pcbBytesNeeded == NULL || lpServicesReturned == NULL)
+    {
+        return ERROR_INVALID_ADDRESS;
+    }
+
     if ((dwBufSize > 0) && (lpBuffer))
     {
         lpStatusPtrW = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, dwBufSize);
@@ -4498,6 +4503,11 @@ DWORD REnumServiceGroupW(
         return ERROR_INVALID_HANDLE;
     }
 
+    if (pcbBytesNeeded == NULL || lpServicesReturned == NULL)
+    {
+        return ERROR_INVALID_ADDRESS;
+    }
+
     *pcbBytesNeeded = 0;
     *lpServicesReturned = 0;
 
@@ -5750,6 +5760,11 @@ DWORD REnumServicesStatusExA(
 
     DPRINT("REnumServicesStatusExA() called\n");
 
+    if (pcbBytesNeeded == NULL || lpServicesReturned == NULL)
+    {
+        return ERROR_INVALID_ADDRESS;
+    }
+
     if (pszGroupName)
     {
         pszGroupNameW = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, (strlen(pszGroupName) + 1) * sizeof(WCHAR));
@@ -5895,6 +5910,11 @@ DWORD REnumServicesStatusExW(
         return ERROR_INVALID_HANDLE;
     }
 
+    if (pcbBytesNeeded == NULL || lpServicesReturned == NULL)
+    {
+        return ERROR_INVALID_ADDRESS;
+    }
+
     *pcbBytesNeeded = 0;
     *lpServicesReturned = 0;
 
diff --git a/reactos/base/system/services/services.c b/reactos/base/system/services/services.c
index 56c3f04a719..2edb6e75887 100644
--- a/reactos/base/system/services/services.c
+++ b/reactos/base/system/services/services.c
@@ -173,7 +173,7 @@ ScmNamedPipeThread(LPVOID Context)
 
     hPipe = (HANDLE)Context;
 
-    DPRINT("ScmNamedPipeThread(%lu) - Accepting SCM commands through named pipe\n", hPipe);
+    DPRINT("ScmNamedPipeThread(%p) - Accepting SCM commands through named pipe\n", hPipe);
 
     for (;;)
     {
@@ -201,13 +201,13 @@ ScmNamedPipeThread(LPVOID Context)
         }
     }
 
-    DPRINT("ScmNamedPipeThread(%lu) - Disconnecting named pipe connection\n", hPipe);
+    DPRINT("ScmNamedPipeThread(%p) - Disconnecting named pipe connection\n", hPipe);
 
     FlushFileBuffers(hPipe);
     DisconnectNamedPipe(hPipe);
     CloseHandle(hPipe);
 
-    DPRINT("ScmNamedPipeThread(%lu) - Done.\n", hPipe);
+    DPRINT("ScmNamedPipeThread(%p) - Done.\n", hPipe);
 
     return ERROR_SUCCESS;
 }
@@ -237,7 +237,7 @@ ScmCreateNamedPipe(VOID)
         return FALSE;
     }
 
-    DPRINT("CreateNamedPipe() - calling ConnectNamedPipe(%x)\n", hPipe);
+    DPRINT("CreateNamedPipe() - calling ConnectNamedPipe(%p)\n", hPipe);
     bConnected = ConnectNamedPipe(hPipe,
                                   NULL) ? TRUE : (GetLastError() == ERROR_PIPE_CONNECTED);
     DPRINT("CreateNamedPipe() - ConnectNamedPipe() returned %d\n", bConnected);
diff --git a/reactos/dll/win32/advapi32/service/scm.c b/reactos/dll/win32/advapi32/service/scm.c
index dceb296d13c..f8cc95a7310 100644
--- a/reactos/dll/win32/advapi32/service/scm.c
+++ b/reactos/dll/win32/advapi32/service/scm.c
@@ -165,6 +165,8 @@ ChangeServiceConfig2A(SC_HANDLE hService,
 
     TRACE("ChangeServiceConfig2A() called\n");
 
+    if (lpInfo == NULL) return TRUE;
+
     /* Fill relevent field of the Info structure */
     Info.dwInfoLevel = dwInfoLevel;
     switch (dwInfoLevel)
@@ -184,9 +186,6 @@ ChangeServiceConfig2A(SC_HANDLE hService,
             return FALSE;
     }
 
-    if (lpInfo == NULL)
-        return TRUE;
-
     RpcTryExcept
     {
         dwError = RChangeServiceConfig2A((SC_RPC_HANDLE)hService,
@@ -224,6 +223,8 @@ ChangeServiceConfig2W(SC_HANDLE hService,
 
     TRACE("ChangeServiceConfig2W() called\n");
 
+    if (lpInfo == NULL) return TRUE;
+
     /* Fill relevent field of the Info structure */
     Info.dwInfoLevel = dwInfoLevel;
     switch (dwInfoLevel)
@@ -242,9 +243,6 @@ ChangeServiceConfig2W(SC_HANDLE hService,
             return FALSE;
     }
 
-    if (lpInfo == NULL)
-        return TRUE;
-
     RpcTryExcept
     {
         dwError = RChangeServiceConfig2W((SC_RPC_HANDLE)hService,
@@ -926,6 +924,12 @@ EnumServiceGroupW(SC_HANDLE hSCManager,
         return FALSE;
     }
 
+    if (pcbBytesNeeded == NULL || lpServicesReturned == NULL)
+    {
+        SetLastError(ERROR_INVALID_ADDRESS);
+        return FALSE;
+    }
+
     if (lpServices == NULL || cbBufSize < sizeof(ENUM_SERVICE_STATUSW))
     {
         lpStatusPtr = &ServiceStatus;
@@ -1027,6 +1031,12 @@ EnumServicesStatusA(SC_HANDLE hSCManager,
         return FALSE;
     }
 
+    if (pcbBytesNeeded == NULL || lpServicesReturned == NULL)
+    {
+        SetLastError(ERROR_INVALID_ADDRESS);
+        return FALSE;
+    }
+
     if (lpServices == NULL || cbBufSize < sizeof(ENUM_SERVICE_STATUSA))
     {
         lpStatusPtr = &ServiceStatus;
@@ -1113,6 +1123,12 @@ EnumServicesStatusW(SC_HANDLE hSCManager,
         return FALSE;
     }
 
+    if (pcbBytesNeeded == NULL || lpServicesReturned == NULL)
+    {
+        SetLastError(ERROR_INVALID_ADDRESS);
+        return FALSE;
+    }
+
     if (lpServices == NULL || cbBufSize < sizeof(ENUM_SERVICE_STATUSW))
     {
         lpStatusPtr = &ServiceStatus;
@@ -1207,8 +1223,13 @@ EnumServicesStatusExA(SC_HANDLE hSCManager,
         return FALSE;
     }
 
-    if (lpServices == NULL ||
-        cbBufSize < sizeof(ENUM_SERVICE_STATUS_PROCESSA))
+    if (pcbBytesNeeded == NULL || lpServicesReturned == NULL)
+    {
+        SetLastError(ERROR_INVALID_ADDRESS);
+        return FALSE;
+    }
+
+    if (lpServices == NULL || cbBufSize < sizeof(ENUM_SERVICE_STATUS_PROCESSA))
     {
         lpStatusPtr = &ServiceStatus;
         dwBufferSize = sizeof(ENUM_SERVICE_STATUS_PROCESSA);
@@ -1307,8 +1328,13 @@ EnumServicesStatusExW(SC_HANDLE hSCManager,
         return FALSE;
     }
 
-    if (lpServices == NULL ||
-        cbBufSize < sizeof(ENUM_SERVICE_STATUS_PROCESSW))
+    if (pcbBytesNeeded == NULL || lpServicesReturned == NULL)
+    {
+        SetLastError(ERROR_INVALID_ADDRESS);
+        return FALSE;
+    }
+
+    if (lpServices == NULL || cbBufSize < sizeof(ENUM_SERVICE_STATUS_PROCESSW))
     {
         lpStatusPtr = &ServiceStatus;
         dwBufferSize = sizeof(ENUM_SERVICE_STATUS_PROCESSW);