diff --git a/reactos/subsys/win32k/objects/brush.c b/reactos/subsys/win32k/objects/brush.c
index b8d6803862a..0c89d915288 100644
--- a/reactos/subsys/win32k/objects/brush.c
+++ b/reactos/subsys/win32k/objects/brush.c
@@ -563,7 +563,7 @@ NtGdiCreateDIBBrush(
    CONST VOID *PackedDIB)
 {
    BITMAPINFO *SafeBitmapInfoAndData;
-   NTSTATUS Status;
+   NTSTATUS Status = STATUS_SUCCESS;
    HBRUSH hBrush;
 
    SafeBitmapInfoAndData = EngAllocMem(0, BitmapInfoSize, 0);
@@ -573,10 +573,24 @@ NtGdiCreateDIBBrush(
       return NULL;
    }
 
-   Status = MmCopyFromCaller(SafeBitmapInfoAndData, BitmapInfoAndData,
-                             BitmapInfoSize);
+   _SEH_TRY
+   {
+      ProbeForRead(BitmapInfoAndData,
+                   BitmapInfoSize,
+                   1);
+      RtlCopyMemory(SafeBitmapInfoAndData,
+                    BitmapInfoAndData,
+                    BitmapInfoSize);
+   }
+   _SEH_HANDLE
+   {
+      Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
+   
    if (!NT_SUCCESS(Status))
    {
+      EngFreeMem(SafeBitmapInfoAndData);
       SetLastNtError(Status);
       return 0;
    }
@@ -632,11 +646,23 @@ NtGdiSetBrushOrgEx(HDC hDC, INT XOrg, INT YOrg, LPPOINT Point)
 
    if (Point != NULL)
    {
-      NTSTATUS Status;
+      NTSTATUS Status = STATUS_SUCCESS;
       POINT SafePoint;
       SafePoint.x = dc->w.brushOrgX;
       SafePoint.y = dc->w.brushOrgY;
-      Status = MmCopyToCaller(Point, &SafePoint, sizeof(POINT));
+      _SEH_TRY
+      {
+         ProbeForWrite(Point,
+                       sizeof(POINT),
+                       1);
+         *Point = SafePoint;
+      }
+      _SEH_HANDLE
+      {
+         Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
+
       if(!NT_SUCCESS(Status))
       {
         DC_UnlockDc(dc);
@@ -661,7 +687,7 @@ NtGdiPolyPatBlt(
    ULONG Reserved)
 {
    PPATRECT rb = NULL;
-   NTSTATUS Status;
+   NTSTATUS Status = STATUS_SUCCESS;
    BOOL Ret;
 
    if (cRects > 0)
@@ -672,7 +698,21 @@ NtGdiPolyPatBlt(
          SetLastWin32Error(ERROR_NOT_ENOUGH_MEMORY);
          return FALSE;
       }
-      Status = MmCopyFromCaller(rb, pRects, sizeof(PATRECT) * cRects);
+      _SEH_TRY
+      {
+         ProbeForRead(pRects,
+                      cRects * sizeof(PATRECT),
+                      1);
+         RtlCopyMemory(rb,
+                       pRects,
+                       cRects * sizeof(PATRECT));
+      }
+      _SEH_HANDLE
+      {
+         Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
+
       if (!NT_SUCCESS(Status))
       {
          ExFreePool(rb);
diff --git a/reactos/subsys/win32k/objects/cliprgn.c b/reactos/subsys/win32k/objects/cliprgn.c
index 8990b2b082c..599318f0428 100644
--- a/reactos/subsys/win32k/objects/cliprgn.c
+++ b/reactos/subsys/win32k/objects/cliprgn.c
@@ -192,7 +192,19 @@ int STDCALL NtGdiGetClipBox(HDC  hDC,
 
   Ret = IntGdiGetClipBox(hDC, &Saferect);
 
-  Status = MmCopyToCaller(rc, &Saferect, sizeof(RECT));
+  _SEH_TRY
+  {
+    ProbeForWrite(rc,
+                  sizeof(RECT),
+                  1);
+    *rc = Saferect;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+
   if(!NT_SUCCESS(Status))
   {
 
@@ -341,7 +353,7 @@ BOOL STDCALL NtGdiPtVisible(HDC  hDC,
 BOOL STDCALL NtGdiRectVisible(HDC  hDC,
                       CONST PRECT  UnsafeRect)
 {
-   NTSTATUS Status;
+   NTSTATUS Status = STATUS_SUCCESS;
    PROSRGNDATA Rgn;
    PDC dc = DC_LockDc(hDC);
    BOOL Result = FALSE;
@@ -353,10 +365,23 @@ BOOL STDCALL NtGdiRectVisible(HDC  hDC,
       return FALSE;
    }
 
-   Status = MmCopyFromCaller(&Rect, UnsafeRect, sizeof(RECT));
+   _SEH_TRY
+   {
+      ProbeForRead(UnsafeRect,
+                   sizeof(RECT),
+                   1);
+      Rect = *UnsafeRect;
+   }
+   _SEH_HANDLE
+   {
+      Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
+
    if(!NT_SUCCESS(Status))
    {
       DC_UnlockDc(dc);
+      SetLastNtError(Status);
       return FALSE;
    }
 
diff --git a/reactos/subsys/win32k/objects/coord.c b/reactos/subsys/win32k/objects/coord.c
index b0e94d53968..612ff02999c 100644
--- a/reactos/subsys/win32k/objects/coord.c
+++ b/reactos/subsys/win32k/objects/coord.c
@@ -63,17 +63,29 @@ BOOL STDCALL NtGdiCombineTransform(LPXFORM  UnsafeXFormResult,
 {
   XFORM  xformTemp;
   XFORM  xform1, xform2;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
   BOOL Ret;
 
-
-  Status = MmCopyFromCaller( &xform1, Unsafexform1, sizeof(XFORM) );
-  if(!NT_SUCCESS(Status))
+  _SEH_TRY
   {
-    SetLastNtError(Status);
-    return FALSE;
+    ProbeForWrite(UnsafeXFormResult,
+                  sizeof(XFORM),
+                  1);
+    ProbeForRead(Unsafexform1,
+                 sizeof(XFORM),
+                 1);
+    ProbeForRead(Unsafexform2,
+                 sizeof(XFORM),
+                 1);
+    xform1 = *Unsafexform1;
+    xform2 = *Unsafexform2;
   }
-  Status = MmCopyFromCaller( &xform2, Unsafexform2, sizeof(XFORM) );
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+
   if(!NT_SUCCESS(Status))
   {
     SetLastNtError(Status);
@@ -83,7 +95,17 @@ BOOL STDCALL NtGdiCombineTransform(LPXFORM  UnsafeXFormResult,
   Ret = IntGdiCombineTransform(&xformTemp, &xform1, &xform2);
 
   /* Copy the result to xformResult */
-  Status = MmCopyToCaller(  UnsafeXFormResult, &xformTemp, sizeof(XFORM) );
+  _SEH_TRY
+  {
+    /* pointer was already probed! */
+    *UnsafeXFormResult = xformTemp;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+
   if(!NT_SUCCESS(Status))
   {
     SetLastNtError(Status);
@@ -131,7 +153,7 @@ NtGdiDPtoLP(HDC  hDC,
 	   int  Count)
 {
    PDC dc;
-   NTSTATUS Status;
+   NTSTATUS Status = STATUS_SUCCESS;
    LPPOINT Points;
    ULONG Size;
 
@@ -159,7 +181,21 @@ NtGdiDPtoLP(HDC  hDC,
      return FALSE;
    }
 
-   Status = MmCopyFromCaller(Points, UnsafePoints, Size);
+   _SEH_TRY
+   {
+      ProbeForWrite(UnsafePoints,
+                    Size,
+                    1);
+      RtlCopyMemory(Points,
+                    UnsafePoints,
+                    Size);
+   }
+   _SEH_HANDLE
+   {
+      Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
+   
    if(!NT_SUCCESS(Status))
    {
      DC_UnlockDc(dc);
@@ -170,7 +206,19 @@ NtGdiDPtoLP(HDC  hDC,
 
    IntDPtoLP(dc, Points, Count);
 
-   Status = MmCopyToCaller(UnsafePoints, Points, Size);
+   _SEH_TRY
+   {
+      /* pointer was already probed! */
+      RtlCopyMemory(UnsafePoints,
+                    Points,
+                    Size);
+   }
+   _SEH_HANDLE
+   {
+      Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
+
    if(!NT_SUCCESS(Status))
    {
      DC_UnlockDc(dc);
@@ -218,7 +266,7 @@ NtGdiGetWorldTransform(HDC  hDC,
                       LPXFORM  XForm)
 {
   PDC  dc;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   dc = DC_LockDc ( hDC );
   if (!dc)
@@ -233,7 +281,18 @@ NtGdiGetWorldTransform(HDC  hDC,
     return FALSE;
   }
 
-  Status = MmCopyToCaller(XForm, &dc->w.xformWorld2Wnd, sizeof(XFORM));
+  _SEH_TRY
+  {
+    ProbeForWrite(XForm,
+                  sizeof(XFORM),
+                  1);
+    *XForm = dc->w.xformWorld2Wnd;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
 
   DC_UnlockDc(dc);
   return NT_SUCCESS(Status);
@@ -280,7 +339,7 @@ BOOL STDCALL
 NtGdiLPtoDP ( HDC hDC, LPPOINT UnsafePoints, INT Count )
 {
    PDC dc;
-   NTSTATUS Status;
+   NTSTATUS Status = STATUS_SUCCESS;
    LPPOINT Points;
    ULONG Size;
 
@@ -308,7 +367,21 @@ NtGdiLPtoDP ( HDC hDC, LPPOINT UnsafePoints, INT Count )
      return FALSE;
    }
 
-   Status = MmCopyFromCaller(Points, UnsafePoints, Size);
+   _SEH_TRY
+   {
+      ProbeForWrite(UnsafePoints,
+                    Size,
+                    1);
+      RtlCopyMemory(Points,
+                    UnsafePoints,
+                    Size);
+   }
+   _SEH_HANDLE
+   {
+      Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
+
    if(!NT_SUCCESS(Status))
    {
      DC_UnlockDc(dc);
@@ -319,7 +392,19 @@ NtGdiLPtoDP ( HDC hDC, LPPOINT UnsafePoints, INT Count )
 
    IntLPtoDP(dc, Points, Count);
 
-   Status = MmCopyToCaller(UnsafePoints, Points, Size);
+   _SEH_TRY
+   {
+      /* pointer was already probed! */
+      RtlCopyMemory(UnsafePoints,
+                    Points,
+                    Size);
+   }
+   _SEH_HANDLE
+   {
+      Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
+
    if(!NT_SUCCESS(Status))
    {
      DC_UnlockDc(dc);
@@ -341,7 +426,7 @@ NtGdiModifyWorldTransform(HDC            hDC,
 {
    PDC dc;
    XFORM SafeXForm;
-   NTSTATUS Status;
+   NTSTATUS Status = STATUS_SUCCESS;
 
    dc = DC_LockDc(hDC);
    if (!dc)
@@ -357,7 +442,19 @@ NtGdiModifyWorldTransform(HDC            hDC,
      return FALSE;
    }
 
-   Status = MmCopyFromCaller(&SafeXForm, UnsafeXForm, sizeof(XFORM));
+   _SEH_TRY
+   {
+      ProbeForRead(UnsafeXForm,
+                   sizeof(XFORM),
+                   1);
+      SafeXForm = *UnsafeXForm;
+   }
+   _SEH_HANDLE
+   {
+      Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
+
    if(!NT_SUCCESS(Status))
    {
      DC_UnlockDc(dc);
@@ -403,8 +500,7 @@ NtGdiOffsetViewportOrgEx(HDC hDC,
                         LPPOINT UnsafePoint)
 {
   PDC      dc;
-  POINT    Point;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   dc = DC_LockDc ( hDC );
   if(!dc)
@@ -415,9 +511,20 @@ NtGdiOffsetViewportOrgEx(HDC hDC,
 
   if (UnsafePoint)
     {
-	Point.x = dc->vportOrgX;
-	Point.y = dc->vportOrgY;
-	Status = MmCopyToCaller(UnsafePoint, &Point, sizeof(POINT));
+        _SEH_TRY
+        {
+            ProbeForWrite(UnsafePoint,
+                          sizeof(POINT),
+                          1);
+            UnsafePoint->x = dc->vportOrgX;
+            UnsafePoint->y = dc->vportOrgY;
+        }
+        _SEH_HANDLE
+        {
+            Status = _SEH_GetExceptionCode();
+        }
+        _SEH_END;
+
 	if ( !NT_SUCCESS(Status) )
 	  {
 	    SetLastNtError(Status);
@@ -452,13 +559,22 @@ NtGdiOffsetWindowOrgEx(HDC  hDC,
 
   if (Point)
     {
-      POINT SafePoint;
-      NTSTATUS Status;
+      NTSTATUS Status = STATUS_SUCCESS;
+      
+      _SEH_TRY
+      {
+         ProbeForWrite(Point,
+                       sizeof(POINT),
+                       1);
+         Point->x = dc->wndOrgX;
+         Point->y = dc->wndOrgY;
+      }
+      _SEH_HANDLE
+      {
+         Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
 
-      SafePoint.x = dc->wndOrgX;
-      SafePoint.y = dc->wndOrgY;
-
-      Status = MmCopyToCaller(Point, &SafePoint, sizeof(POINT));
       if(!NT_SUCCESS(Status))
       {
         SetLastNtError(Status);
@@ -594,13 +710,22 @@ NtGdiSetViewportExtEx(HDC  hDC,
 
   if (Size)
     {
-      SIZE SafeSize;
-      NTSTATUS Status;
+      NTSTATUS Status = STATUS_SUCCESS;
 
-      SafeSize.cx = dc->vportExtX;
-      SafeSize.cy = dc->vportExtY;
+      _SEH_TRY
+      {
+         ProbeForWrite(Size,
+                       sizeof(SIZE),
+                       1);
+         Size->cx = dc->vportExtX;
+         Size->cy = dc->vportExtY;
+      }
+      _SEH_HANDLE
+      {
+         Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
 
-      Status = MmCopyToCaller(Size, &SafeSize, sizeof(SIZE));
       if(!NT_SUCCESS(Status))
       {
         SetLastNtError(Status);
@@ -636,13 +761,22 @@ NtGdiSetViewportOrgEx(HDC  hDC,
 
   if (Point)
     {
-      POINT SafePoint;
-      NTSTATUS Status;
+      NTSTATUS Status = STATUS_SUCCESS;
+      
+      _SEH_TRY
+      {
+         ProbeForWrite(Point,
+                       sizeof(POINT),
+                       1);
+         Point->x = dc->vportOrgX;
+         Point->y = dc->vportOrgY;
+      }
+      _SEH_HANDLE
+      {
+         Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
 
-      SafePoint.x = dc->vportOrgX;
-      SafePoint.y = dc->vportOrgY;
-
-      Status = MmCopyToCaller(Point, &SafePoint, sizeof(POINT));
       if(!NT_SUCCESS(Status))
       {
         SetLastNtError(Status);
@@ -690,13 +824,22 @@ NtGdiSetWindowExtEx(HDC  hDC,
 
   if (Size)
     {
-      SIZE SafeSize;
-      NTSTATUS Status;
+      NTSTATUS Status = STATUS_SUCCESS;
+      
+      _SEH_TRY
+      {
+         ProbeForWrite(Size,
+                       sizeof(SIZE),
+                       1);
+         Size->cx = dc->wndExtX;
+         Size->cy = dc->wndExtY;
+      }
+      _SEH_HANDLE
+      {
+         Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
 
-      SafeSize.cx = dc->wndExtX;
-      SafeSize.cy = dc->wndExtY;
-
-      Status = MmCopyToCaller(Size, &SafeSize, sizeof(SIZE));
       if(!NT_SUCCESS(Status))
       {
         SetLastNtError(Status);
@@ -732,13 +875,22 @@ NtGdiSetWindowOrgEx(HDC  hDC,
 
   if (Point)
     {
-      POINT SafePoint;
-      NTSTATUS Status;
+      NTSTATUS Status = STATUS_SUCCESS;
+      
+      _SEH_TRY
+      {
+         ProbeForWrite(Point,
+                       sizeof(POINT),
+                       1);
+         Point->x = dc->wndOrgX;
+         Point->y = dc->wndOrgY;
+      }
+      _SEH_HANDLE
+      {
+         Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
 
-      SafePoint.x = dc->wndOrgX;
-      SafePoint.y = dc->wndOrgY;
-
-      Status = MmCopyToCaller(Point, &SafePoint, sizeof(POINT));
       if(!NT_SUCCESS(Status))
       {
         SetLastNtError(Status);
@@ -762,7 +914,7 @@ NtGdiSetWorldTransform(HDC  hDC,
                       CONST LPXFORM  XForm)
 {
   PDC  dc;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   dc = DC_LockDc (hDC);
   if ( !dc )
@@ -785,7 +937,19 @@ NtGdiSetWorldTransform(HDC  hDC,
     return  FALSE;
   }
 
-  Status = MmCopyFromCaller(&dc->w.xformWorld2Wnd, XForm, sizeof(XFORM));
+  _SEH_TRY
+  {
+    ProbeForRead(XForm,
+                 sizeof(XFORM),
+                 1);
+    dc->w.xformWorld2Wnd = *XForm;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+
   if(!NT_SUCCESS(Status))
   {
     DC_UnlockDc(dc);
diff --git a/reactos/subsys/win32k/objects/dc.c b/reactos/subsys/win32k/objects/dc.c
index 676dc2d8d1b..e436def9dd3 100644
--- a/reactos/subsys/win32k/objects/dc.c
+++ b/reactos/subsys/win32k/objects/dc.c
@@ -69,7 +69,7 @@ VOID FASTCALL Int##FuncName ( PDC dc, LP##type pt) \
 } \
 BOOL STDCALL NtGdi##FuncName ( HDC hdc, LP##type pt ) \
 { \
-  NTSTATUS Status; \
+  NTSTATUS Status = STATUS_SUCCESS; \
   type Safept; \
   PDC dc; \
   if(!pt) \
@@ -84,7 +84,18 @@ BOOL STDCALL NtGdi##FuncName ( HDC hdc, LP##type pt ) \
   } \
   Int##FuncName( dc, &Safept); \
   DC_UnlockDc(dc); \
-  Status = MmCopyToCaller(pt, &Safept, sizeof( type )); \
+  _SEH_TRY \
+  { \
+    ProbeForWrite(pt, \
+                  sizeof( type ), \
+                  1); \
+    *pt = Safept; \
+  } \
+  _SEH_HANDLE \
+  { \
+    Status = _SEH_GetExceptionCode(); \
+  } \
+  _SEH_END; \
   if(!NT_SUCCESS(Status)) \
   { \
     SetLastNtError(Status); \
@@ -830,11 +841,25 @@ NtGdiCreateDC(PUNICODE_STRING Driver,
   UNICODE_STRING SafeDriver, SafeDevice;
   DEVMODEW SafeInitData;
   HDC Ret;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   if(InitData)
   {
-    Status = MmCopyFromCaller(&SafeInitData, InitData, sizeof(DEVMODEW));
+    _SEH_TRY
+    {
+      ProbeForRead(InitData,
+                   sizeof(DEVMODEW),
+                   1);
+      RtlCopyMemory(&SafeInitData,
+                    InitData,
+                    sizeof(DEVMODEW));
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
     if(!NT_SUCCESS(Status))
     {
       SetLastNtError(Status);
@@ -878,11 +903,24 @@ NtGdiCreateIC(PUNICODE_STRING Driver,
   UNICODE_STRING SafeDriver, SafeDevice;
   DEVMODEW SafeInitData;
   HDC Ret;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   if(InitData)
   {
-    Status = MmCopyFromCaller(&SafeInitData, InitData, sizeof(DEVMODEW));
+    _SEH_TRY
+    {
+      ProbeForRead(InitData,
+                   sizeof(DEVMODEW),
+                   1);
+      RtlCopyMemory(&SafeInitData,
+                    InitData,
+                    sizeof(DEVMODEW));
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
     if(!NT_SUCCESS(Status))
     {
       SetLastNtError(Status);
@@ -1076,7 +1114,7 @@ NtGdiGetDCOrgEx(HDC  hDC, LPPOINT  Point)
   BOOL Ret;
   DC *dc;
   POINT SafePoint;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   if(!Point)
   {
@@ -1093,7 +1131,19 @@ NtGdiGetDCOrgEx(HDC  hDC, LPPOINT  Point)
 
   Ret = IntGdiGetDCOrgEx(dc, &SafePoint);
 
-  Status = MmCopyToCaller(Point, &SafePoint, sizeof(POINT));
+  _SEH_TRY
+  {
+    ProbeForWrite(Point,
+                  sizeof(POINT),
+                  1);
+    *Point = SafePoint;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+
   if(!NT_SUCCESS(Status))
   {
     SetLastNtError(Status);
@@ -1621,12 +1671,30 @@ NtGdiGetObject(HANDLE handle, INT count, LPVOID buffer)
 {
   INT Ret;
   LPVOID SafeBuf;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   if (count <= 0)
   {
     return 0;
   }
+  
+  _SEH_TRY
+  {
+    ProbeForWrite(buffer,
+                  count,
+                  1);
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+  
+  if(!NT_SUCCESS(Status))
+  {
+    SetLastNtError(Status);
+    return 0;
+  }
 
   SafeBuf = ExAllocatePoolWithTag(PagedPool, count, TAG_GDIOBJ);
   if(!SafeBuf)
@@ -1637,7 +1705,19 @@ NtGdiGetObject(HANDLE handle, INT count, LPVOID buffer)
 
   Ret = IntGdiGetObject(handle, count, SafeBuf);
 
-  Status = MmCopyToCaller(buffer, SafeBuf, count);
+  _SEH_TRY
+  {
+    /* pointer already probed! */
+    RtlCopyMemory(buffer,
+                  SafeBuf,
+                  count);
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+
   ExFreePool(SafeBuf);
   if(!NT_SUCCESS(Status))
   {
diff --git a/reactos/subsys/win32k/objects/fillshap.c b/reactos/subsys/win32k/objects/fillshap.c
index 8cfea2c5833..8c6a557abb5 100644
--- a/reactos/subsys/win32k/objects/fillshap.c
+++ b/reactos/subsys/win32k/objects/fillshap.c
@@ -845,7 +845,7 @@ NtGdiPolygon(HDC          hDC,
 {
   DC *dc;
   LPPOINT Safept;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
   BOOL Ret = FALSE;
 
   if ( Count < 2 )
@@ -853,6 +853,24 @@ NtGdiPolygon(HDC          hDC,
     SetLastWin32Error(ERROR_INVALID_PARAMETER);
     return FALSE;
   }
+  
+  _SEH_TRY
+  {
+    ProbeForRead(UnsafePoints,
+                 Count * sizeof(POINT),
+                 1);
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+  
+  if (!NT_SUCCESS(Status))
+  {
+    SetLastNtError(Status);
+    return FALSE;
+  }
 
   dc = DC_LockDc(hDC);
   if(!dc)
@@ -870,7 +888,19 @@ NtGdiPolygon(HDC          hDC,
       SetLastWin32Error(ERROR_NOT_ENOUGH_MEMORY);
     else
     {
-      Status = MmCopyFromCaller(Safept, UnsafePoints, sizeof(POINT) * Count);
+      _SEH_TRY
+      {
+        /* pointer was already probed! */
+        RtlCopyMemory(Safept,
+                      UnsafePoints,
+                      Count * sizeof(POINT));
+      }
+      _SEH_HANDLE
+      {
+        Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
+
       if(!NT_SUCCESS(Status))
         SetLastNtError(Status);
       else
@@ -913,6 +943,28 @@ NtGdiPolyPolygon(HDC           hDC,
 
   if(Count > 0)
   {
+    _SEH_TRY
+    {
+      ProbeForRead(Points,
+                   Count * sizeof(POINT),
+                   1);
+      ProbeForRead(PolyCounts,
+                   Count * sizeof(INT),
+                   1);
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
+    if (!NT_SUCCESS(Status))
+    {
+      DC_UnlockDc(dc);
+      SetLastNtError(Status);
+      return FALSE;
+    }
+  
     Safept = ExAllocatePoolWithTag(PagedPool, (sizeof(POINT) + sizeof(INT)) * Count, TAG_SHAPE);
     if(!Safept)
     {
@@ -922,16 +974,23 @@ NtGdiPolyPolygon(HDC           hDC,
     }
 
     SafePolyPoints = (LPINT)&Safept[Count];
-
-    Status = MmCopyFromCaller(Safept, Points, sizeof(POINT) * Count);
-    if(!NT_SUCCESS(Status))
+    
+    _SEH_TRY
     {
-      DC_UnlockDc(dc);
-      ExFreePool(Safept);
-      SetLastNtError(Status);
-      return FALSE;
+      /* pointers already probed! */
+      RtlCopyMemory(Safept,
+                    Points,
+                    Count * sizeof(POINT));
+      RtlCopyMemory(SafePolyPoints,
+                    PolyCounts,
+                    Count * sizeof(INT));
     }
-    Status = MmCopyFromCaller(SafePolyPoints, PolyCounts, sizeof(INT) * Count);
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
     if(!NT_SUCCESS(Status))
     {
       DC_UnlockDc(dc);
@@ -1520,7 +1579,7 @@ NtGdiGradientFill(
   PTRIVERTEX SafeVertex;
   PVOID SafeMesh;
   ULONG SizeMesh;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   dc = DC_LockDc(hdc);
   if(!dc)
@@ -1555,6 +1614,28 @@ NtGdiGradientFill(
       SetLastWin32Error(ERROR_INVALID_PARAMETER);
       return FALSE;
   }
+  
+  _SEH_TRY
+  {
+    ProbeForRead(pVertex,
+                 uVertex * sizeof(TRIVERTEX),
+                 1);
+    ProbeForRead(pMesh,
+                 SizeMesh,
+                 1);
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+  
+  if (!NT_SUCCESS(Status))
+  {
+    DC_UnlockDc(dc);
+    SetLastWin32Error(Status);
+    return FALSE;
+  }
 
   if(!(SafeVertex = ExAllocatePoolWithTag(PagedPool, (uVertex * sizeof(TRIVERTEX)) + SizeMesh, TAG_SHAPE)))
   {
@@ -1562,16 +1643,25 @@ NtGdiGradientFill(
     SetLastWin32Error(ERROR_NOT_ENOUGH_MEMORY);
     return FALSE;
   }
-  Status = MmCopyFromCaller(SafeVertex, pVertex, uVertex * sizeof(TRIVERTEX));
-  if(!NT_SUCCESS(Status))
-  {
-    DC_UnlockDc(dc);
-    ExFreePool(SafeVertex);
-    SetLastNtError(Status);
-    return FALSE;
-  }
+  
   SafeMesh = (PTRIVERTEX)(SafeVertex + uVertex);
-  Status = MmCopyFromCaller(SafeMesh, pMesh, SizeMesh);
+
+  _SEH_TRY
+  {
+    /* pointers were already probed! */
+    RtlCopyMemory(SafeVertex,
+                  pVertex,
+                  uVertex * sizeof(TRIVERTEX));
+    RtlCopyMemory(SafeMesh,
+                  pMesh,
+                  SizeMesh);
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+  
   if(!NT_SUCCESS(Status))
   {
     DC_UnlockDc(dc);
diff --git a/reactos/subsys/win32k/objects/line.c b/reactos/subsys/win32k/objects/line.c
index 0d7f1f67eb2..754a788d933 100644
--- a/reactos/subsys/win32k/objects/line.c
+++ b/reactos/subsys/win32k/objects/line.c
@@ -503,7 +503,7 @@ NtGdiMoveToEx(HDC      hDC,
 {
   DC *dc;
   POINT SafePoint;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
   BOOL Ret;
 
   dc = DC_LockDc(hDC);
@@ -521,7 +521,19 @@ NtGdiMoveToEx(HDC      hDC,
 
   if(Point)
   {
-    Status = MmCopyFromCaller(&SafePoint, Point, sizeof(POINT));
+    _SEH_TRY
+    {
+      ProbeForRead(Point,
+                   sizeof(POINT),
+                   1);
+      SafePoint = *Point;
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
     if(!NT_SUCCESS(Status))
     {
       DC_UnlockDc(dc);
@@ -544,7 +556,7 @@ NtGdiPolyBezier(HDC           hDC,
 {
   DC *dc;
   LPPOINT Safept;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
   BOOL Ret;
 
   dc = DC_LockDc(hDC);
@@ -562,6 +574,25 @@ NtGdiPolyBezier(HDC           hDC,
 
   if(Count > 0)
   {
+    _SEH_TRY
+    {
+      ProbeForRead(pt,
+                   Count * sizeof(POINT),
+                   1);
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+    
+    if (!NT_SUCCESS(Status))
+    {
+      DC_UnlockDc(dc);
+      SetLastNtError(Status);
+      return FALSE;
+    }
+    
     Safept = ExAllocatePoolWithTag(PagedPool, sizeof(POINT) * Count, TAG_BEZIER);
     if(!Safept)
     {
@@ -570,7 +601,19 @@ NtGdiPolyBezier(HDC           hDC,
       return FALSE;
     }
 
-    Status = MmCopyFromCaller(Safept, pt, sizeof(POINT) * Count);
+    _SEH_TRY
+    {
+      /* pointers were already probed */
+      RtlCopyMemory(Safept,
+                    pt,
+                    Count * sizeof(POINT));
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
     if(!NT_SUCCESS(Status))
     {
       DC_UnlockDc(dc);
@@ -601,7 +644,7 @@ NtGdiPolyBezierTo(HDC  hDC,
 {
   DC *dc;
   LPPOINT Safept;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
   BOOL Ret;
 
   dc = DC_LockDc(hDC);
@@ -619,6 +662,25 @@ NtGdiPolyBezierTo(HDC  hDC,
 
   if(Count > 0)
   {
+    _SEH_TRY
+    {
+      ProbeForRead(pt,
+                   Count * sizeof(POINT),
+                   1);
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
+    if (!NT_SUCCESS(Status))
+    {
+      DC_UnlockDc(dc);
+      SetLastNtError(Status);
+      return FALSE;
+    }
+    
     Safept = ExAllocatePoolWithTag(PagedPool, sizeof(POINT) * Count, TAG_BEZIER);
     if(!Safept)
     {
@@ -627,7 +689,19 @@ NtGdiPolyBezierTo(HDC  hDC,
       return FALSE;
     }
 
-    Status = MmCopyFromCaller(Safept, pt, sizeof(POINT) * Count);
+    _SEH_TRY
+    {
+      /* pointers were already probed */
+      RtlCopyMemory(Safept,
+                    pt,
+                    Count * sizeof(POINT));
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
     if(!NT_SUCCESS(Status))
     {
       DC_UnlockDc(dc);
@@ -669,7 +743,7 @@ NtGdiPolyline(HDC            hDC,
 {
   DC *dc;
   LPPOINT Safept;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
   BOOL Ret;
 
   dc = DC_LockDc(hDC);
@@ -687,6 +761,25 @@ NtGdiPolyline(HDC            hDC,
 
   if(Count >= 2)
   {
+    _SEH_TRY
+    {
+      ProbeForRead(pt,
+                   Count * sizeof(POINT),
+                   1);
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
+    if (!NT_SUCCESS(Status))
+    {
+      DC_UnlockDc(dc);
+      SetLastNtError(Status);
+      return FALSE;
+    }
+    
     Safept = ExAllocatePoolWithTag(PagedPool, sizeof(POINT) * Count, TAG_SHAPE);
     if(!Safept)
     {
@@ -695,7 +788,19 @@ NtGdiPolyline(HDC            hDC,
       return FALSE;
     }
 
-    Status = MmCopyFromCaller(Safept, pt, sizeof(POINT) * Count);
+    _SEH_TRY
+    {
+      /* pointers were already probed */
+      RtlCopyMemory(Safept,
+                    pt,
+                    Count * sizeof(POINT));
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
     if(!NT_SUCCESS(Status))
     {
       DC_UnlockDc(dc);
@@ -726,7 +831,7 @@ NtGdiPolylineTo(HDC            hDC,
 {
   DC *dc;
   LPPOINT Safept;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
   BOOL Ret;
 
   dc = DC_LockDc(hDC);
@@ -744,6 +849,25 @@ NtGdiPolylineTo(HDC            hDC,
 
   if(Count > 0)
   {
+    _SEH_TRY
+    {
+      ProbeForRead(pt,
+                   Count * sizeof(POINT),
+                   1);
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
+    if (!NT_SUCCESS(Status))
+    {
+      DC_UnlockDc(dc);
+      SetLastNtError(Status);
+      return FALSE;
+    }
+    
     Safept = ExAllocatePoolWithTag(PagedPool, sizeof(POINT) * Count, TAG_SHAPE);
     if(!Safept)
     {
@@ -752,7 +876,19 @@ NtGdiPolylineTo(HDC            hDC,
       return FALSE;
     }
 
-    Status = MmCopyFromCaller(Safept, pt, sizeof(POINT) * Count);
+    _SEH_TRY
+    {
+      /* pointers were already probed */
+      RtlCopyMemory(Safept,
+                    pt,
+                    Count * sizeof(POINT));
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
     if(!NT_SUCCESS(Status))
     {
       DC_UnlockDc(dc);
@@ -785,7 +921,7 @@ NtGdiPolyPolyline(HDC            hDC,
   DC *dc;
   LPPOINT Safept;
   LPDWORD SafePolyPoints;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
   BOOL Ret;
 
   dc = DC_LockDc(hDC);
@@ -803,6 +939,28 @@ NtGdiPolyPolyline(HDC            hDC,
 
   if(Count > 0)
   {
+    _SEH_TRY
+    {
+      ProbeForRead(pt,
+                   Count * sizeof(POINT),
+                   1);
+      ProbeForRead(PolyPoints,
+                   Count * sizeof(DWORD),
+                   1);
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
+    if (!NT_SUCCESS(Status))
+    {
+      DC_UnlockDc(dc);
+      SetLastNtError(Status);
+      return FALSE;
+    }
+    
     Safept = ExAllocatePoolWithTag(PagedPool, (sizeof(POINT) + sizeof(DWORD)) * Count, TAG_SHAPE);
     if(!Safept)
     {
@@ -812,16 +970,23 @@ NtGdiPolyPolyline(HDC            hDC,
     }
 
     SafePolyPoints = (LPDWORD)&Safept[Count];
-
-    Status = MmCopyFromCaller(Safept, pt, sizeof(POINT) * Count);
-    if(!NT_SUCCESS(Status))
+    
+    _SEH_TRY
     {
-      DC_UnlockDc(dc);
-      ExFreePool(Safept);
-      SetLastNtError(Status);
-      return FALSE;
+      /* pointers were already probed */
+      RtlCopyMemory(Safept,
+                    pt,
+                    Count * sizeof(POINT));
+      RtlCopyMemory(SafePolyPoints,
+                    PolyPoints,
+                    Count * sizeof(DWORD));
     }
-    Status = MmCopyFromCaller(SafePolyPoints, PolyPoints, sizeof(DWORD) * Count);
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+
     if(!NT_SUCCESS(Status))
     {
       DC_UnlockDc(dc);
diff --git a/reactos/subsys/win32k/objects/pen.c b/reactos/subsys/win32k/objects/pen.c
index 90383c0ef39..c634f6d9f50 100644
--- a/reactos/subsys/win32k/objects/pen.c
+++ b/reactos/subsys/win32k/objects/pen.c
@@ -97,9 +97,21 @@ HPEN STDCALL
 NtGdiCreatePenIndirect(CONST PLOGPEN LogPen)
 {
    LOGPEN SafeLogPen;
-   NTSTATUS Status;
+   NTSTATUS Status = STATUS_SUCCESS;
+
+   _SEH_TRY
+   {
+     ProbeForRead(LogPen,
+                  sizeof(LOGPEN),
+                  1);
+     SafeLogPen = *LogPen;
+   }
+   _SEH_HANDLE
+   {
+     Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
 
-   Status = MmCopyFromCaller(&SafeLogPen, LogPen, sizeof(LOGPEN));
    if (!NT_SUCCESS(Status))
    {
       SetLastNtError(Status);
diff --git a/reactos/subsys/win32k/objects/print.c b/reactos/subsys/win32k/objects/print.c
index bd4a0ba2362..8f328318029 100644
--- a/reactos/subsys/win32k/objects/print.c
+++ b/reactos/subsys/win32k/objects/print.c
@@ -154,7 +154,7 @@ NtGdiExtEscape(
    PDC      pDC = DC_LockDc(hDC);
    LPVOID   SafeInData = NULL;
    LPVOID   SafeOutData = NULL;
-   NTSTATUS Status;
+   NTSTATUS Status = STATUS_SUCCESS;
    INT      Result;
 
    if ( pDC == NULL )
@@ -170,6 +170,25 @@ NtGdiExtEscape(
 
    if ( InSize && UnsafeInData )
    {
+      _SEH_TRY
+      {
+        ProbeForRead(UnsafeInData,
+                     InSize,
+                     1);
+      }
+      _SEH_HANDLE
+      {
+        Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
+      
+      if (!NT_SUCCESS(Status))
+      {
+        DC_UnlockDc(pDC);
+        SetLastNtError(Status);
+        return -1;
+      }
+      
       SafeInData = ExAllocatePoolWithTag ( PagedPool, InSize, TAG_PRINT );
       if ( !SafeInData )
       {
@@ -177,7 +196,20 @@ NtGdiExtEscape(
          SetLastWin32Error(ERROR_NOT_ENOUGH_MEMORY);
          return -1;
       }
-      Status = MmCopyFromCaller ( SafeInData, UnsafeInData, InSize );
+      
+      _SEH_TRY
+      {
+        /* pointers were already probed! */
+        RtlCopyMemory(SafeInData,
+                      UnsafeInData,
+                      InSize);
+      }
+      _SEH_HANDLE
+      {
+        Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
+
       if ( !NT_SUCCESS(Status) )
       {
          ExFreePool ( SafeInData );
@@ -189,13 +221,32 @@ NtGdiExtEscape(
 
    if ( OutSize && UnsafeOutData )
    {
+      _SEH_TRY
+      {
+        ProbeForWrite(UnsafeOutData,
+                      OutSize,
+                      1);
+      }
+      _SEH_HANDLE
+      {
+        Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
+
+      if (!NT_SUCCESS(Status))
+      {
+        SetLastNtError(Status);
+        goto freeout;
+      }
+      
       SafeOutData = ExAllocatePoolWithTag ( PagedPool, OutSize, TAG_PRINT );
       if ( !SafeOutData )
       {
+         SetLastWin32Error(ERROR_NOT_ENOUGH_MEMORY);
+freeout:
          if ( SafeInData )
             ExFreePool ( SafeInData );
          DC_UnlockDc(pDC);
-         SetLastWin32Error(ERROR_NOT_ENOUGH_MEMORY);
          return -1;
       }
    }
@@ -209,7 +260,19 @@ NtGdiExtEscape(
 
    if ( SafeOutData )
    {
-      Status = MmCopyToCaller ( UnsafeOutData, SafeOutData, OutSize );
+      _SEH_TRY
+      {
+        /* pointers were already probed! */
+        RtlCopyMemory(UnsafeOutData,
+                      SafeOutData,
+                      OutSize);
+      }
+      _SEH_HANDLE
+      {
+        Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
+
       ExFreePool ( SafeOutData );
       if ( !NT_SUCCESS(Status) )
       {
diff --git a/reactos/subsys/win32k/objects/rect.c b/reactos/subsys/win32k/objects/rect.c
index 1d6289ac093..4ebda5b6dc1 100644
--- a/reactos/subsys/win32k/objects/rect.c
+++ b/reactos/subsys/win32k/objects/rect.c
@@ -35,11 +35,23 @@ BOOL STDCALL
 NtGdiSetEmptyRect(PRECT UnsafeRect)
 {
   RECT Rect;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   IntGdiSetEmptyRect(&Rect);
 
-  Status = MmCopyToCaller(UnsafeRect, &Rect, sizeof(RECT));
+  _SEH_TRY
+  {
+    ProbeForWrite(UnsafeRect,
+                  sizeof(RECT),
+                  1);
+    *UnsafeRect = Rect;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+
   if (! NT_SUCCESS(Status))
     {
       SetLastNtError(Status);
@@ -59,9 +71,20 @@ BOOL STDCALL
 NtGdiIsEmptyRect(const RECT* UnsafeRect)
 {
   RECT Rect;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
-  Status = MmCopyFromCaller(&Rect, UnsafeRect, sizeof(RECT));
+  _SEH_TRY
+  {
+    ProbeForRead(UnsafeRect,
+                 sizeof(RECT),
+                 1);
+    Rect = *UnsafeRect;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
   if (! NT_SUCCESS(Status))
     {
       SetLastNtError(Status);
@@ -84,9 +107,20 @@ BOOL STDCALL
 NtGdiOffsetRect(LPRECT UnsafeRect, INT x, INT y)
 {
   RECT Rect;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
-  Status = MmCopyFromCaller(&Rect, UnsafeRect, sizeof(RECT));
+  _SEH_TRY
+  {
+    ProbeForRead(UnsafeRect,
+                 sizeof(RECT),
+                 1);
+    Rect = *UnsafeRect;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
   if (! NT_SUCCESS(Status))
     {
       SetLastNtError(Status);
@@ -95,7 +129,18 @@ NtGdiOffsetRect(LPRECT UnsafeRect, INT x, INT y)
 
   IntGdiOffsetRect(&Rect, x, y);
 
-  Status = MmCopyToCaller(UnsafeRect, &Rect, sizeof(RECT));
+  _SEH_TRY
+  {
+    ProbeForWrite(UnsafeRect,
+                  sizeof(RECT),
+                  1);
+    *UnsafeRect = Rect;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
   if (! NT_SUCCESS(Status))
     {
       SetLastNtError(Status);
@@ -142,16 +187,25 @@ BOOL STDCALL
 NtGdiUnionRect(PRECT UnsafeDest, const RECT* UnsafeSrc1, const RECT* UnsafeSrc2)
 {
   RECT Dest, Src1, Src2;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
   BOOL Ret;
 
-  Status = MmCopyFromCaller(&Src1, UnsafeSrc1, sizeof(RECT));
-  if (! NT_SUCCESS(Status))
-    {
-      SetLastNtError(Status);
-      return FALSE;
-    }
-  Status = MmCopyFromCaller(&Src2, UnsafeSrc2, sizeof(RECT));
+  _SEH_TRY
+  {
+    ProbeForRead(UnsafeSrc1,
+                 sizeof(RECT),
+                 1);
+    ProbeForRead(UnsafeSrc2,
+                 sizeof(RECT),
+                 1);
+    Src1 = *UnsafeSrc1;
+    Src2 = *UnsafeSrc2;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
   if (! NT_SUCCESS(Status))
     {
       SetLastNtError(Status);
@@ -162,7 +216,18 @@ NtGdiUnionRect(PRECT UnsafeDest, const RECT* UnsafeSrc1, const RECT* UnsafeSrc2)
 
   if (Ret)
     {
-      Status = MmCopyToCaller(UnsafeDest, &Dest, sizeof(RECT));
+      _SEH_TRY
+      {
+        ProbeForWrite(UnsafeDest,
+                      sizeof(RECT),
+                      1);
+        *UnsafeDest = Dest;
+      }
+      _SEH_HANDLE
+      {
+        Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
       if (! NT_SUCCESS(Status))
         {
           SetLastNtError(Status);
@@ -186,11 +251,22 @@ BOOL STDCALL
 NtGdiSetRect(PRECT UnsafeRect, INT left, INT top, INT right, INT bottom)
 {
   RECT Rect;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   IntGdiSetRect(&Rect, left, top, right, bottom);
 
-  Status = MmCopyToCaller(UnsafeRect, &Rect, sizeof(RECT));
+  _SEH_TRY
+  {
+    ProbeForWrite(UnsafeRect,
+                  sizeof(RECT),
+                  1);
+    *UnsafeRect = Rect;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
   if (! NT_SUCCESS(Status))
     {
       SetLastNtError(Status);
@@ -223,16 +299,25 @@ BOOL STDCALL
 NtGdiIntersectRect(PRECT UnsafeDest, const RECT* UnsafeSrc1, const RECT* UnsafeSrc2)
 {
   RECT Dest, Src1, Src2;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
   BOOL Ret;
 
-  Status = MmCopyFromCaller(&Src1, UnsafeSrc1, sizeof(RECT));
-  if (! NT_SUCCESS(Status))
-    {
-      SetLastNtError(Status);
-      return FALSE;
-    }
-  Status = MmCopyFromCaller(&Src2, UnsafeSrc2, sizeof(RECT));
+  _SEH_TRY
+  {
+    ProbeForRead(UnsafeSrc1,
+                 sizeof(RECT),
+                 1);
+    ProbeForRead(UnsafeSrc2,
+                 sizeof(RECT),
+                 1);
+    Src1 = *UnsafeSrc1;
+    Src2 = *UnsafeSrc2;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
   if (! NT_SUCCESS(Status))
     {
       SetLastNtError(Status);
@@ -243,7 +328,18 @@ NtGdiIntersectRect(PRECT UnsafeDest, const RECT* UnsafeSrc1, const RECT* UnsafeS
 
   if (Ret)
     {
-      Status = MmCopyToCaller(UnsafeDest, &Dest, sizeof(RECT));
+      _SEH_TRY
+      {
+        ProbeForWrite(UnsafeDest,
+                      sizeof(RECT),
+                      1);
+        *UnsafeDest = Dest;
+      }
+      _SEH_HANDLE
+      {
+        Status = _SEH_GetExceptionCode();
+      }
+      _SEH_END;
       if (! NT_SUCCESS(Status))
         {
           SetLastNtError(Status);
diff --git a/reactos/subsys/win32k/objects/region.c b/reactos/subsys/win32k/objects/region.c
index 31418c04591..0b39ef1a146 100644
--- a/reactos/subsys/win32k/objects/region.c
+++ b/reactos/subsys/win32k/objects/region.c
@@ -2029,9 +2029,20 @@ STDCALL
 NtGdiCreateEllipticRgnIndirect(CONST PRECT Rect)
 {
   RECT SafeRect;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
-  Status = MmCopyFromCaller(&SafeRect, Rect, sizeof(RECT));
+  _SEH_TRY
+  {
+    ProbeForRead(Rect,
+                 sizeof(RECT),
+                 1);
+    SafeRect = *Rect;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
   if(!NT_SUCCESS(Status))
   {
     SetLastNtError(Status);
@@ -2063,9 +2074,20 @@ HRGN STDCALL
 NtGdiCreateRectRgnIndirect(CONST PRECT rc)
 {
   RECT SafeRc;
-  NTSTATUS Status;
+  NTSTATUS Status = STATUS_SUCCESS;
 
-  Status = MmCopyFromCaller(&SafeRc, rc, sizeof(RECT));
+  _SEH_TRY
+  {
+    ProbeForRead(rc,
+                 sizeof(RECT),
+                 1);
+    SafeRc = *rc;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
   if (!NT_SUCCESS(Status))
     {
       return(NULL);
@@ -2229,9 +2251,9 @@ NtGdiExtCreateRegion(CONST XFORM *Xform,
                           CONST RGNDATA *RgnData)
 {
    HRGN hRgn;
-   RGNDATA SafeRgnData;
    PROSRGNDATA Region;
-   NTSTATUS Status;
+   DWORD nCount = 0;
+   NTSTATUS Status = STATUS_SUCCESS;
 
    if (Count < FIELD_OFFSET(RGNDATA, Buffer))
    {
@@ -2239,14 +2261,30 @@ NtGdiExtCreateRegion(CONST XFORM *Xform,
       return NULL;
    }
 
-   Status = MmCopyFromCaller(&SafeRgnData, RgnData, min(Count, sizeof(RGNDATA)));
+   _SEH_TRY
+   {
+     ProbeForRead(RgnData,
+                  Count,
+                  1);
+     nCount = RgnData->rdh.nCount;
+     if((Count - FIELD_OFFSET(RGNDATA, Buffer)) / sizeof(RECT) < nCount)
+     {
+       Status = STATUS_INVALID_PARAMETER;
+       _SEH_LEAVE;
+     }
+   }
+   _SEH_HANDLE
+   {
+     Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
    if (!NT_SUCCESS(Status))
    {
-      SetLastWin32Error(ERROR_INVALID_PARAMETER);
+      SetLastNtError(Status);
       return NULL;
    }
 
-   hRgn = RGNDATA_AllocRgn(SafeRgnData.rdh.nCount);
+   hRgn = RGNDATA_AllocRgn(nCount);
    if (hRgn == NULL)
    {
       SetLastWin32Error(ERROR_NOT_ENOUGH_MEMORY);
@@ -2260,10 +2298,20 @@ NtGdiExtCreateRegion(CONST XFORM *Xform,
       return FALSE;
    }
 
-   RtlCopyMemory(&Region->rdh, &SafeRgnData, FIELD_OFFSET(RGNDATA, Buffer));
-
-   Status = MmCopyFromCaller(Region->Buffer, RgnData->Buffer,
-                             Count - FIELD_OFFSET(RGNDATA, Buffer));
+   _SEH_TRY
+   {
+     RtlCopyMemory(&Region->rdh,
+                   RgnData,
+                   FIELD_OFFSET(RGNDATA, Buffer));
+     RtlCopyMemory(Region->Buffer,
+                   RgnData->Buffer,
+                   Count - FIELD_OFFSET(RGNDATA, Buffer));
+   }
+   _SEH_HANDLE
+   {
+     Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
    if (!NT_SUCCESS(Status))
    {
       SetLastWin32Error(ERROR_INVALID_PARAMETER);
@@ -2354,6 +2402,7 @@ NtGdiGetRgnBox(HRGN  hRgn,
   PROSRGNDATA  Rgn;
   RECT SafeRect;
   DWORD ret;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   if (!(Rgn = RGNDATA_LockRgn(hRgn)))
     {
@@ -2367,7 +2416,19 @@ NtGdiGetRgnBox(HRGN  hRgn,
       return ret;
     }
 
-  if (!NT_SUCCESS(MmCopyToCaller(pRect, &SafeRect, sizeof(RECT))))
+  _SEH_TRY
+  {
+    ProbeForWrite(pRect,
+                  sizeof(RECT),
+                  1);
+    *pRect = SafeRect;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+  if (!NT_SUCCESS(Status))
     {
       return ERROR;
     }
@@ -2576,15 +2637,30 @@ NtGdiRectInRegion(HRGN  hRgn,
   PROSRGNDATA Rgn;
   RECT rc;
   BOOL Ret;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   if(!(Rgn = RGNDATA_LockRgn(hRgn)))
   {
     return ERROR;
   }
 
-  if (!NT_SUCCESS(MmCopyFromCaller(&rc, unsaferc, sizeof(RECT))))
+  _SEH_TRY
+  {
+    ProbeForRead(unsaferc,
+                 sizeof(RECT),
+                 1);
+    rc = *unsaferc;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
+  
+  if (!NT_SUCCESS(Status))
     {
       RGNDATA_UnlockRgn(Rgn);
+      SetLastNtError(Status);
       DPRINT1("NtGdiRectInRegion: bogus rc\n");
       return ERROR;
     }
@@ -2635,17 +2711,31 @@ NtGdiUnionRectWithRgn(HRGN hDest, CONST PRECT UnsafeRect)
 {
   RECT SafeRect;
   PROSRGNDATA Rgn;
+  NTSTATUS Status = STATUS_SUCCESS;
 
   if(!(Rgn = (PROSRGNDATA)RGNDATA_LockRgn(hDest)))
   {
      SetLastWin32Error(ERROR_INVALID_HANDLE);
      return NULL;
   }
+  
+  _SEH_TRY
+  {
+    ProbeForRead(UnsafeRect,
+                 sizeof(RECT),
+                 1);
+    SafeRect = *UnsafeRect;
+  }
+  _SEH_HANDLE
+  {
+    Status = _SEH_GetExceptionCode();
+  }
+  _SEH_END;
 
-  if (! NT_SUCCESS(MmCopyFromCaller(&SafeRect, UnsafeRect, sizeof(RECT))))
+  if (! NT_SUCCESS(Status))
     {
       RGNDATA_UnlockRgn(Rgn);
-      SetLastWin32Error(ERROR_INVALID_PARAMETER);
+      SetLastNtError(Status);
       return NULL;
     }
 
@@ -2668,6 +2758,7 @@ DWORD STDCALL NtGdiGetRegionData(HRGN hrgn, DWORD count, LPRGNDATA rgndata)
 {
     DWORD size;
     PROSRGNDATA obj = RGNDATA_LockRgn( hrgn );
+    NTSTATUS Status = STATUS_SUCCESS;
 
     if(!obj)
 		return 0;
@@ -2681,16 +2772,31 @@ DWORD STDCALL NtGdiGetRegionData(HRGN hrgn, DWORD count, LPRGNDATA rgndata)
 		else		/* user requested buffer size with rgndata NULL */
 		    return size + sizeof(RGNDATAHEADER);
     }
-
-	//first we copy the header then we copy buffer
-	if( !NT_SUCCESS( MmCopyToCaller( rgndata, obj, sizeof( RGNDATAHEADER )))){
-		RGNDATA_UnlockRgn( obj );
-		return 0;
-	}
-	if( !NT_SUCCESS( MmCopyToCaller( (char*)rgndata+sizeof( RGNDATAHEADER ), obj->Buffer, size ))){
-		RGNDATA_UnlockRgn( obj );
-		return 0;
-	}
+    
+    _SEH_TRY
+    {
+      ProbeForWrite(rgndata,
+                    count,
+                    1);
+      RtlCopyMemory(rgndata,
+                    obj,
+                    sizeof(RGNDATAHEADER));
+      RtlCopyMemory((PVOID)((ULONG_PTR)rgndata + (ULONG_PTR)sizeof(RGNDATAHEADER)),
+                    obj->Buffer,
+                    size);
+    }
+    _SEH_HANDLE
+    {
+      Status = _SEH_GetExceptionCode();
+    }
+    _SEH_END;
+    
+    if(!NT_SUCCESS(Status))
+    {
+      SetLastNtError(Status);
+      RGNDATA_UnlockRgn( obj );
+      return 0;
+    }
 
     RGNDATA_UnlockRgn( obj );
     return size + sizeof(RGNDATAHEADER);
@@ -3291,7 +3397,7 @@ NtGdiCreatePolygonRgn(CONST PPOINT  pt,
                       INT  PolyFillMode)
 {
    POINT *SafePoints;
-   NTSTATUS Status;
+   NTSTATUS Status = STATUS_SUCCESS;
    HRGN hRgn;
 
 
@@ -3329,6 +3435,24 @@ NtGdiCreatePolygonRgn(CONST PPOINT  pt,
       RGNDATA_UnlockRgn(rgn);
       return hRgn;
    }
+   
+   _SEH_TRY
+   {
+      ProbeForRead(pt,
+                   Count * sizeof(POINT),
+                   1);
+   }
+   _SEH_HANDLE
+   {
+      Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
+   
+   if (!NT_SUCCESS(Status))
+   {
+      SetLastNtError(Status);
+      return (HRGN)0;
+   }
 
    if (!(SafePoints = ExAllocatePoolWithTag(PagedPool, Count * sizeof(POINT), TAG_REGION)))
    {
@@ -3336,7 +3460,18 @@ NtGdiCreatePolygonRgn(CONST PPOINT  pt,
       return (HRGN)0;
    }
 
-   Status = MmCopyFromCaller(SafePoints, pt, Count * sizeof(POINT));
+   _SEH_TRY
+   {
+      /* pointers were already probed! */
+      RtlCopyMemory(SafePoints,
+                    pt,
+                    Count * sizeof(POINT));
+   }
+   _SEH_HANDLE
+   {
+      Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
    if (!NT_SUCCESS(Status))
    {
       ExFreePool(SafePoints);
@@ -3361,7 +3496,7 @@ NtGdiCreatePolyPolygonRgn(CONST PPOINT  pt,
    INT *SafePolyCounts;
    INT nPoints, nEmpty, nInvalid, i;
    HRGN hRgn;
-   NTSTATUS Status;
+   NTSTATUS Status = STATUS_SUCCESS;
 
    if (pt == NULL || PolyCounts == NULL || Count == 0 ||
        (PolyFillMode != WINDING && PolyFillMode != ALTERNATE))
@@ -3369,6 +3504,27 @@ NtGdiCreatePolyPolygonRgn(CONST PPOINT  pt,
       /* Windows doesn't set a last error here */
       return (HRGN)0;
    }
+   
+   _SEH_TRY
+   {
+      ProbeForRead(PolyCounts,
+                   Count * sizeof(INT),
+                   1);
+      ProbeForRead(pt,
+                   nPoints * sizeof(POINT),
+                   1);
+   }
+   _SEH_HANDLE
+   {
+      Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
+   
+   if (!NT_SUCCESS(Status))
+   {
+      SetLastNtError(Status);
+      return (HRGN)0;
+   }
 
    if (!(SafePolyCounts = ExAllocatePoolWithTag(PagedPool, Count * sizeof(INT), TAG_REGION)))
    {
@@ -3376,7 +3532,19 @@ NtGdiCreatePolyPolygonRgn(CONST PPOINT  pt,
       return (HRGN)0;
    }
 
-   Status = MmCopyFromCaller(SafePolyCounts, PolyCounts, Count * sizeof(INT));
+   _SEH_TRY
+   {
+      /* pointers were already probed! */
+      RtlCopyMemory(SafePolyCounts,
+                    PolyCounts,
+                    Count * sizeof(INT));
+   }
+   _SEH_HANDLE
+   {
+      Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
+   
    if (!NT_SUCCESS(Status))
    {
       ExFreePool(SafePolyCounts);
@@ -3423,7 +3591,18 @@ NtGdiCreatePolyPolygonRgn(CONST PPOINT  pt,
       return (HRGN)0;
    }
 
-   Status = MmCopyFromCaller(Safept, pt, nPoints * sizeof(POINT));
+   _SEH_TRY
+   {
+      /* pointers were already probed! */
+      RtlCopyMemory(Safept,
+                    pt,
+                    Count * sizeof(POINT));
+   }
+   _SEH_HANDLE
+   {
+      Status = _SEH_GetExceptionCode();
+   }
+   _SEH_END;
    if (!NT_SUCCESS(Status))
    {
       ExFreePool(Safept);