Index: /trunk/src/VBox/Runtime/generic/memsafer-generic.cpp
===================================================================
--- /trunk/src/VBox/Runtime/generic/memsafer-generic.cpp	(revision 52019)
+++ /trunk/src/VBox/Runtime/generic/memsafer-generic.cpp	(revision 52020)
@@ -136,5 +136,6 @@
         if (RT_SUCCESS(rc))
         {
-            rc = SUPR3PageProtect(pvNew, NIL_RTR0PTR, PAGE_SIZE + cbUser, PAGE_SIZE, RTMEM_PROT_NONE);
+            Assert(cb == (size_t)((uint32_t)(PAGE_SIZE + cbUser)));
+            rc = SUPR3PageProtect(pvNew, NIL_RTR0PTR, PAGE_SIZE + (uint32_t)cbUser, PAGE_SIZE, RTMEM_PROT_NONE);
             if (RT_SUCCESS(rc))
             {