From 95dd343a4be064f3fa32d55da41fb367369e6828 Mon Sep 17 00:00:00 2001
From: lgao4 <lgao4@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Tue, 1 Dec 2009 10:29:39 +0000
Subject: [PATCH] Make MEDIA DEVICE PATH on 2 byte aligned to avoid the access
 to unaligned device path node.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9503 6f19259b-4bc3-4df7-8a09-765794883524
---
 MdePkg/Library/DxeServicesLib/DxeServicesLib.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/MdePkg/Library/DxeServicesLib/DxeServicesLib.c b/MdePkg/Library/DxeServicesLib/DxeServicesLib.c
index fa54c7bd01..107bf4bd62 100644
--- a/MdePkg/Library/DxeServicesLib/DxeServicesLib.c
+++ b/MdePkg/Library/DxeServicesLib/DxeServicesLib.c
@@ -435,6 +435,7 @@ GetFileBufferByFilePath (
 {
   EFI_DEVICE_PATH_PROTOCOL          *DevicePathNode;
   EFI_DEVICE_PATH_PROTOCOL          *OrigDevicePathNode;
+  EFI_DEVICE_PATH_PROTOCOL          *TempDevicePathNode;
   EFI_HANDLE                        Handle;
   EFI_GUID                          *FvNameGuid;
   EFI_FIRMWARE_VOLUME2_PROTOCOL     *FwVol;
@@ -462,6 +463,7 @@ GetFileBufferByFilePath (
   //
   // Init local variable
   //
+  TempDevicePathNode  = NULL;
   FvNameGuid          = NULL;
   FileInfo            = NULL;
   FileHandle          = NULL;
@@ -544,11 +546,23 @@ GetFileBufferByFilePath (
       //
       Status = Volume->OpenVolume (Volume, &FileHandle);
       if (!EFI_ERROR (Status)) {
+        //
+        // Duplicate the device path to avoid the access to unaligned device path node.
+        // Because the device path consists of one or more FILE PATH MEDIA DEVICE PATH
+        // nodes, It assures the fields in device path nodes are 2 byte aligned.
+        //
+        TempDevicePathNode = DuplicateDevicePath (DevicePathNode);
+        if (TempDevicePathNode == NULL) {
+          FileHandle->Close (FileHandle);
+          Status = EFI_OUT_OF_RESOURCES;
+          goto Finish;
+        }
         //
         // Parse each MEDIA_FILEPATH_DP node. There may be more than one, since the
         // directory information and filename can be seperate. The goal is to inch
         // our way down each device path node and close the previous node
         //
+        DevicePathNode = TempDevicePathNode;
         while (!IsDevicePathEnd (DevicePathNode) && !EFI_ERROR (Status)) {
           if (DevicePathType (DevicePathNode) != MEDIA_DEVICE_PATH ||
               DevicePathSubType (DevicePathNode) != MEDIA_FILEPATH_DP) {
@@ -620,7 +634,7 @@ GetFileBufferByFilePath (
           }
         }
         //
-        // Close the file and Free FileInfo since we are done
+        // Close the file and Free FileInfo and TempDevicePathNode since we are done
         // 
         if (FileInfo != NULL) {
           FreePool (FileInfo);
@@ -628,6 +642,7 @@ GetFileBufferByFilePath (
         if (FileHandle != NULL) {
           FileHandle->Close (FileHandle);
         }
+        FreePool (TempDevicePathNode);
       }
     }
     goto Finish;
-- 
2.39.2