Index: win32ss/gdi/ntgdi/bitmaps.c
===================================================================
--- win32ss/gdi/ntgdi/bitmaps.c	(revision 73499)
+++ win32ss/gdi/ntgdi/bitmaps.c	(working copy)
@@ -429,11 +429,12 @@
     return Bmp;
 }
 
-BOOL
-APIENTRY
-NtGdiGetBitmapDimension(
+static
+BOOL FASTCALL
+IntGetBitmapDimension(
     HBITMAP hBitmap,
-    LPSIZE psizDim)
+    LPSIZE psizDim,
+    BOOL ProbeBuffer)
 {
     PSURFACE psurfBmp;
     BOOL bResult = TRUE;
@@ -441,6 +442,19 @@
     if (hBitmap == NULL)
         return FALSE;
 
+    if (ProbeBuffer)
+    {
+        _SEH2_TRY
+        {
+            ProbeForWrite(psizDim, sizeof(*psizDim), 1);
+        }
+        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
+        {
+            _SEH2_YIELD(return FALSE);
+        }
+        _SEH2_END
+    }
+
     /* Lock the bitmap */
     psurfBmp = SURFACE_ShareLockSurface(hBitmap);
     if (psurfBmp == NULL)
@@ -452,7 +466,6 @@
     /* Use SEH to copy the data to the caller */
     _SEH2_TRY
     {
-        ProbeForWrite(psizDim, sizeof(SIZE), 1);
         *psizDim = psurfBmp->sizlDim;
     }
     _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
@@ -467,7 +480,25 @@
     return bResult;
 }
 
+BOOL
+NTAPI
+GreGetBitmapDimension(
+    _In_ HBITMAP hBitmap,
+    _Out_ LPSIZE psizDim)
+{
+    return IntGetBitmapDimension(hBitmap, psizDim, FALSE);
+}
 
+BOOL
+APIENTRY
+NtGdiGetBitmapDimension(
+    HBITMAP hBitmap,
+    LPSIZE psizDim)
+{
+    return IntGetBitmapDimension(hBitmap, psizDim, TRUE);
+}
+
+
 VOID
 FASTCALL
 UnsafeGetBitmapBits(
Index: win32ss/gdi/ntgdi/bitmaps.h
===================================================================
--- win32ss/gdi/ntgdi/bitmaps.h	(revision 73499)
+++ win32ss/gdi/ntgdi/bitmaps.h	(working copy)
@@ -50,3 +50,10 @@
     _Inout_ PSURFACE psurf,
     _In_ ULONG cjBits,
     _In_ const VOID *pvBits);
+
+BOOL
+NTAPI
+GreGetBitmapDimension(
+    _In_ HBITMAP hBitmap,
+    _Out_ LPSIZE psizDim);
+
Index: win32ss/user/ntuser/caret.c
===================================================================
--- win32ss/user/ntuser/caret.c	(revision 73499)
+++ win32ss/user/ntuser/caret.c	(working copy)
@@ -43,7 +43,7 @@
 
     if (CaretInfo->Bitmap)
     {
-        if (!NtGdiGetBitmapDimension(CaretInfo->Bitmap, &CaretInfo->Size))
+        if (!GreGetBitmapDimension(CaretInfo->Bitmap, &CaretInfo->Size))
         {
             ERR("Failed to get bitmap dimensions\n");
             return;