--- xnu/xnu-3789.31.2/libkern/c++/OSData.cpp
+++ xnu/xnu-4903.221.2/libkern/c++/OSData.cpp
@@ -76,8 +76,8 @@
 	if (inCapacity < page_size) data = (void *) kalloc_container(inCapacity);
 	else {
 	    kern_return_t kr;
-	    inCapacity = round_page_32(inCapacity);
-	    kr = kmem_alloc(kernel_map, (vm_offset_t *)&data, inCapacity, IOMemoryTag(kernel_map));
+	    if (round_page_overflow(inCapacity, &inCapacity)) kr = KERN_RESOURCE_SHORTAGE;
+	    else kr = kmem_alloc(kernel_map, (vm_offset_t *)&data, inCapacity, IOMemoryTag(kernel_map));
 	    if (KERN_SUCCESS != kr) data = NULL;
 	}
         if (!data)
@@ -289,7 +289,9 @@
     if (capacity == EXTERNAL)
         return false;
     
-    newSize = length + inLength;
+    if (os_add_overflow(length, inLength, &newSize))
+        return false;
+
     if ( (newSize > capacity) && newSize > ensureCapacity(newSize) )
         return false;
 
@@ -313,7 +315,9 @@
     if (capacity == EXTERNAL)
         return false;
     
-    newSize = length + inLength;
+    if (os_add_overflow(length, inLength, &newSize))
+        return false;
+
     if ( (newSize > capacity) && newSize > ensureCapacity(newSize) )
         return false;