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

1 files changed, 16 insertions, 1 deletions

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;

@@ -545,10 +547,22 @@ 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;