From 0196c24a94c65a7d8ccbd111adff06b84d595a55 Mon Sep 17 00:00:00 2001
From: Dandan Bi <dandan.bi@intel.com>
Date: Fri, 15 Jan 2016 09:50:40 +0000
Subject: [PATCH] MdeModulePkg:Fix the potential memory leak issue in Display
 Engine

The MenuOption insert to gMenuOption allocate memory every time,but not free.
Now add the code to free it.And for Date/Time,it will create 3 menus,but previously
the Description point to the same address,so when free the Description,it will cause
issue,now reset the Description pointer.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Dandan Bi <dandan.bi@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19647 6f19259b-4bc3-4df7-8a09-765794883524
---
 .../Universal/DisplayEngineDxe/FormDisplay.c  | 46 +++++++++++++++----
 1 file changed, 38 insertions(+), 8 deletions(-)

diff --git a/MdeModulePkg/Universal/DisplayEngineDxe/FormDisplay.c b/MdeModulePkg/Universal/DisplayEngineDxe/FormDisplay.c
index a391442d16..37cfcc591f 100644
--- a/MdeModulePkg/Universal/DisplayEngineDxe/FormDisplay.c
+++ b/MdeModulePkg/Universal/DisplayEngineDxe/FormDisplay.c
@@ -1,7 +1,7 @@
 /** @file
 Entry and initialization module for the browser.
 
-Copyright (c) 2007 - 2015, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2007 - 2016, Intel Corporation. All rights reserved.<BR>
 Copyright (c) 2014, Hewlett-Packard Development Company, L.P.<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
@@ -604,7 +604,6 @@ UiAddMenuOption (
   UI_MENU_OPTION   *MenuOption;
   UINTN            Index;
   UINTN            Count;
-  CHAR16           *String;
   UINT16           NumberOfLines;
   UINT16           GlyphWidth;
   UINT16           Width;
@@ -621,9 +620,6 @@ UiAddMenuOption (
   PromptId = GetPrompt (Statement->OpCode);
   ASSERT (PromptId != 0);
 
-  String = GetToken (PromptId, gFormData->HiiHandle);
-  ASSERT (String != NULL);
-
   if (Statement->OpCode->OpCode == EFI_IFR_DATE_OP || Statement->OpCode->OpCode == EFI_IFR_TIME_OP) {
     Count = 3;
   }
@@ -633,7 +629,7 @@ UiAddMenuOption (
     ASSERT (MenuOption);
 
     MenuOption->Signature   = UI_MENU_OPTION_SIGNATURE;
-    MenuOption->Description = String;
+    MenuOption->Description = GetToken (PromptId, gFormData->HiiHandle);
     MenuOption->Handle      = gFormData->HiiHandle;
     MenuOption->ThisTag     = Statement;
     MenuOption->NestInStatement = NestIn;
@@ -697,11 +693,11 @@ UiAddMenuOption (
       (Statement->OpCode->OpCode != EFI_IFR_DATE_OP) && 
       (Statement->OpCode->OpCode != EFI_IFR_TIME_OP)) {
       Width  = GetWidth (MenuOption, NULL);
-      for (; GetLineByWidth (String, Width, &GlyphWidth,&ArrayEntry, &OutputString) != 0x0000;) {
+      for (; GetLineByWidth (MenuOption->Description, Width, &GlyphWidth,&ArrayEntry, &OutputString) != 0x0000;) {
         //
         // If there is more string to process print on the next row and increment the Skip value
         //
-        if (StrLen (&String[ArrayEntry]) != 0) {
+        if (StrLen (&MenuOption->Description[ArrayEntry]) != 0) {
           NumberOfLines++;
         }
         FreePool (OutputString);
@@ -3729,6 +3725,35 @@ UiDisplayMenu (
   }
 }
 
+/**
+  Free the UI Menu Option structure data.
+
+  @param   MenuOptionList         Point to the menu option list which need to be free.
+
+**/
+
+VOID
+FreeMenuOptionData(
+  LIST_ENTRY           *MenuOptionList
+  )
+{
+  LIST_ENTRY           *Link;
+  UI_MENU_OPTION       *Option;
+
+  //
+  // Free menu option list
+  //
+  while (!IsListEmpty (MenuOptionList)) {
+    Link = GetFirstNode (MenuOptionList);
+    Option = MENU_OPTION_FROM_LINK (Link);
+    if (Option->Description != NULL){
+      FreePool(Option->Description);
+    }
+    RemoveEntryList (&Option->Link);
+    FreePool (Option);
+  }
+}
+
 /**
 
   Base on the browser status info to show an pop up message.
@@ -4001,6 +4026,11 @@ FormDisplay (
   CopyGuid (&gOldFormEntry.FormSetGuid, &FormData->FormSetGuid);
   gOldFormEntry.FormId    = FormData->FormId;
 
+  //
+  //Free the Ui menu option list.
+  //
+  FreeMenuOptionData(&gMenuOption);
+
   return Status;
 }