ArmPkg/BdsLinuxFdt.c: Check that FDT blob is correctly loaded.

Add some checks in the code loading an FDT blob from a memory-mapped device
so that UEFI will detect and print an error message if the address
range doesn't cover the whole file.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@14192 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 25 insertions, 12 deletions

diff --git a/ArmPkg/Library/BdsLib/BdsLinuxFdt.c b/ArmPkg/Library/BdsLib/BdsLinuxFdt.c
index 5fccf8cac7..1baa237162 100644
--- a/ArmPkg/Library/BdsLib/BdsLinuxFdt.c
+++ b/ArmPkg/Library/BdsLib/BdsLinuxFdt.c
@@ -1,14 +1,14 @@
 /** @file

 *

-*  Copyright (c) 2011-2012, ARM Limited. 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        

-*  http://opensource.org/licenses/bsd-license.php                                            

+*  Copyright (c) 2011-2013, ARM Limited. All rights reserved.

 *

-*  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     

-*  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

+*  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

+*  http://opensource.org/licenses/bsd-license.php

+*

+*  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,

+*  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

 *

 **/

 

@@ -243,6 +243,7 @@ PrepareFdt (
   UINTN                 Pages;

   BOOLEAN               PsciSmcSupported;

   UINTN                 Rx;

+  UINTN                 OriginalFdtSize;

 

   //

   // Ensure the Power State Coordination Interface (PSCI) SMCs are there if supported

@@ -271,16 +272,28 @@ PrepareFdt (
     }

   }

 

+  //

+  // Sanity checks on the original FDT blob.

+  //

   err = fdt_check_header ((VOID*)(UINTN)(*FdtBlobBase));

   if (err != 0) {

     Print (L"ERROR: Device Tree header not valid (err:%d)\n", err);

     return EFI_INVALID_PARAMETER;

   }

 

+  // The original FDT blob might have been loaded partially.

+  // Check that it is not the case.

+  OriginalFdtSize = (UINTN)fdt_totalsize ((VOID*)(UINTN)(*FdtBlobBase));

+  if (OriginalFdtSize > *FdtBlobSize) {

+    Print (L"ERROR: Incomplete FDT. Only %d/%d bytes have been loaded.\n",

+           *FdtBlobSize, OriginalFdtSize);

+    return EFI_INVALID_PARAMETER;

+  }

+

   //

   // Allocate memory for the new FDT

   //

-  NewFdtBlobSize = fdt_totalsize((VOID*)(UINTN)(*FdtBlobBase)) + FDT_ADDITIONAL_ENTRIES_SIZE;

+  NewFdtBlobSize = OriginalFdtSize + FDT_ADDITIONAL_ENTRIES_SIZE;

 

   // Try below a watermark address

   Status = EFI_NOT_FOUND;

@@ -370,10 +383,10 @@ PrepareFdt (
     if (node >= 0) {

       fdt_setprop_string(fdt, node, "name", "memory");

       fdt_setprop_string(fdt, node, "device_type", "memory");

-      

+

       GetSystemMemoryResources (&ResourceList);

       Resource = (BDS_SYSTEM_MEMORY_RESOURCE*)ResourceList.ForwardLink;

-      

+

       if (sizeof(UINTN) == sizeof(UINT32)) {

         Region.Base = cpu_to_fdt32((UINTN)Resource->PhysicalStart);

         Region.Size = cpu_to_fdt32((UINTN)Resource->ResourceLength);

@@ -507,7 +520,7 @@ PrepareFdt (
   return EFI_SUCCESS;

 

 FAIL_NEW_FDT:

-  *FdtBlobSize = (UINTN)fdt_totalsize ((VOID*)(UINTN)(*FdtBlobBase));

+  *FdtBlobSize = OriginalFdtSize;

   // Return success even if we failed to update the FDT blob. The original one is still valid.

   return EFI_SUCCESS;

 }