From 1564e9ac2cd2756b400feb98676e1a53806fcea2 Mon Sep 17 00:00:00 2001
From: eric_tian <eric_tian@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Wed, 19 Mar 2008 02:05:57 +0000
Subject: [PATCH] [Description] Duplicate the device path prior to the access
 to it [Impaction] directly access the device path may cause an exception when
 the device path includes some unaligned device path nodes [Reference Info] In
 the case of ISCSI, there is a situation that the device path may consists of
 some unaligned device path node. it causes the unaligned exception when we
 access the node.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@4905 6f19259b-4bc3-4df7-8a09-765794883524
---
 MdeModulePkg/Core/Dxe/Image/ImageFile.c | 80 +++++++++++++++----------
 1 file changed, 49 insertions(+), 31 deletions(-)

diff --git a/MdeModulePkg/Core/Dxe/Image/ImageFile.c b/MdeModulePkg/Core/Dxe/Image/ImageFile.c
index 5d8293a734..b9c8c657b8 100644
--- a/MdeModulePkg/Core/Dxe/Image/ImageFile.c
+++ b/MdeModulePkg/Core/Dxe/Image/ImageFile.c
@@ -1,6 +1,6 @@
 /*++
 
-Copyright (c) 2006 - 2007, Intel Corporation
+Copyright (c) 2006 - 2008, Intel Corporation
 All rights reserved. This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -83,7 +83,9 @@ Returns:
   EFI_FILE_INFO                     *FileInfo;
   UINTN                             FileInfoSize;
   EFI_GUID                          *NameGuid;
+  FILEPATH_DEVICE_PATH              *OriginalFilePathNode;
 
+  OriginalFilePathNode = NULL;
   *AuthenticationStatus = 0;
   ZeroMem (ImageFileHandle, sizeof (IMAGE_FILE_HANDLE));
   ImageFileHandle->Signature = IMAGE_FILE_HANDLE_SIGNATURE;
@@ -187,41 +189,57 @@ Returns:
     //
     Status = Volume->OpenVolume (Volume, &FileHandle);
     if (!EFI_ERROR (Status)) {
-
       //
-      // 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
+      // 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. 
       //
-      while (!IsDevicePathEnd (&FilePathNode->Header)) {
-        if (DevicePathType (&FilePathNode->Header) != MEDIA_DEVICE_PATH ||
-            DevicePathSubType (&FilePathNode->Header) != MEDIA_FILEPATH_DP) {
-          Status = EFI_UNSUPPORTED;
-        }
-
-        if (EFI_ERROR (Status)) {
-          //
-          // Exit loop on Error
-          //
-          break;
-        }
-
-        LastHandle = FileHandle;
-        FileHandle = NULL;
-        Status = LastHandle->Open (
-                              LastHandle,
-                              &FileHandle,
-                              FilePathNode->PathName,
-                              EFI_FILE_MODE_READ,
-                              0
-                              );
-
+      FilePathNode = (FILEPATH_DEVICE_PATH *)CoreDuplicateDevicePath((EFI_DEVICE_PATH_PROTOCOL *)(UINTN)FilePathNode);
+      if (FilePathNode == NULL) {
+        FileHandle->Close (FileHandle);
+        Status = EFI_OUT_OF_RESOURCES;
+      } else {
+        OriginalFilePathNode = FilePathNode;
         //
-        // Close the previous node
+        // 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
         //
-        LastHandle->Close (LastHandle);
+        while (!IsDevicePathEnd (&FilePathNode->Header)) {
+          if (DevicePathType (&FilePathNode->Header) != MEDIA_DEVICE_PATH ||
+              DevicePathSubType (&FilePathNode->Header) != MEDIA_FILEPATH_DP) {
+            Status = EFI_UNSUPPORTED;
+          }
 
-        FilePathNode = (FILEPATH_DEVICE_PATH *) NextDevicePathNode (&FilePathNode->Header);
+          if (EFI_ERROR (Status)) {
+            //
+            // Exit loop on Error
+            //
+            break;
+          }
+
+          LastHandle = FileHandle;
+          FileHandle = NULL;
+
+          Status = LastHandle->Open (
+                                LastHandle,
+                                &FileHandle,
+                                FilePathNode->PathName,
+                                EFI_FILE_MODE_READ,
+                                0
+                                );
+
+          //
+          // Close the previous node
+          //
+          LastHandle->Close (LastHandle);
+
+          FilePathNode = (FILEPATH_DEVICE_PATH *) NextDevicePathNode (&FilePathNode->Header);
+        }
+        //
+        // Free the allocated memory pool 
+        //
+        CoreFreePool(OriginalFilePathNode);
       }
 
       if (!EFI_ERROR (Status)) {