diff --git a/MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIo.c b/MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIo.c
index e8af46f6c0..ba61300911 100644
--- a/MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIo.c
+++ b/MdeModulePkg/Universal/Disk/DiskIoDxe/DiskIo.c
@@ -642,7 +642,7 @@ DiskIoCreateSubtaskList (
       InsertTailList (Subtasks, &Subtask->Link);
     }
 
-    Subtask = DiskIoCreateSubtask (Write, OverRunLba, 0, OverRun, WorkingBuffer, BufferPtr, Blocking);
+    Subtask = DiskIoCreateSubtask (Write, OverRunLba, 0, OverRun, WorkingBuffer, BufferPtr + BufferSize, Blocking);
     if (Subtask == NULL) {
       goto Done;
     }