Re: [edk2] [PATCH 2/3] MdeModulePkg/DxeCore: Ensure FfsFileHeader 8 bytes aligned [CVE-2018-3630]

2019-02-26 Thread Wang, Jian J


Reviewed-by: Jian J Wang 


> -Original Message-
> From: edk2-devel [mailto:edk2-devel-boun...@lists.01.org] On Behalf Of Jian J
> Wang
> Sent: Wednesday, February 27, 2019 12:04 AM
> To: edk2-devel@lists.01.org
> Cc: Wu, Hao A ; Yao, Jiewen ;
> Gao, Liming ; Zeng, Star 
> Subject: [edk2] [PATCH 2/3] MdeModulePkg/DxeCore: Ensure FfsFileHeader 8
> bytes aligned [CVE-2018-3630]
> 
> From: Star Zeng 
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=864
> 
> To follow PI spec, ensure FfsFileHeader 8 bytes aligned.
> 
> For the integrity of FV(especially non-MemoryMapped FV) layout,
> let CachedFv point to FV beginning, but not (FV + FV header).
> 
> And current code only handles (FwVolHeader->ExtHeaderOffset != 0) path,
> update code to also handle (FwVolHeader->ExtHeaderOffset == 0) path.
> 
> Cc: Jiewen Yao 
> Cc: Liming Gao 
> Cc: Jian J Wang 
> Cc: Hao Wu 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Star Zeng 
> ---
>  MdeModulePkg/Core/Dxe/FwVol/FwVol.c | 65 +++--
>  1 file changed, 14 insertions(+), 51 deletions(-)
> 
> diff --git a/MdeModulePkg/Core/Dxe/FwVol/FwVol.c
> b/MdeModulePkg/Core/Dxe/FwVol/FwVol.c
> index 93ddcc3591..28fce46a95 100644
> --- a/MdeModulePkg/Core/Dxe/FwVol/FwVol.c
> +++ b/MdeModulePkg/Core/Dxe/FwVol/FwVol.c
> @@ -3,7 +3,7 @@
>Layers on top of Firmware Block protocol to produce a file abstraction
>of FV based files.
> 
> -Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
> +Copyright (c) 2006 - 2019, 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
> @@ -329,8 +329,6 @@ FvCheck (
>FFS_FILE_LIST_ENTRY   *FfsFileEntry;
>EFI_FFS_FILE_HEADER   *FfsHeader;
>UINT8 *CacheLocation;
> -  UINTN LbaOffset;
> -  UINTN HeaderSize;
>UINTN Index;
>EFI_LBA   LbaIndex;
>UINTN Size;
> @@ -353,11 +351,7 @@ FvCheck (
>  return Status;
>}
> 
> -  //
> -  // Size is the size of the FV minus the head. We have already allocated
> -  // the header to check to make sure the volume is valid
> -  //
> -  Size = (UINTN)(FwVolHeader->FvLength - FwVolHeader->HeaderLength);
> +  Size = (UINTN) FwVolHeader->FvLength;
>if ((FvbAttributes & EFI_FVB2_MEMORY_MAPPED) != 0) {
>  FvDevice->IsMemoryMapped = TRUE;
> 
> @@ -369,7 +363,7 @@ FvCheck (
>  //
>  // Don't cache memory mapped FV really.
>  //
> -FvDevice->CachedFv = (UINT8 *) (UINTN) (PhysicalAddress + FwVolHeader-
> >HeaderLength);
> +FvDevice->CachedFv = (UINT8 *) (UINTN) PhysicalAddress;
>} else {
>  FvDevice->IsMemoryMapped = FALSE;
>  FvDevice->CachedFv = AllocatePool (Size);
> @@ -380,52 +374,27 @@ FvCheck (
>}
> 
>//
> -  // Remember a pointer to the end fo the CachedFv
> +  // Remember a pointer to the end of the CachedFv
>//
>FvDevice->EndOfCachedFv = FvDevice->CachedFv + Size;
> 
>if (!FvDevice->IsMemoryMapped) {
>  //
> -// Copy FV minus header into memory using the block map we have all ready
> -// read into memory.
> +// Copy FV into memory using the block map.
>  //
>  BlockMap = FwVolHeader->BlockMap;
>  CacheLocation = FvDevice->CachedFv;
>  LbaIndex = 0;
> -LbaOffset = 0;
> -HeaderSize = FwVolHeader->HeaderLength;
>  while ((BlockMap->NumBlocks != 0) || (BlockMap->Length != 0)) {
> -  Index = 0;
> -  Size  = BlockMap->Length;
> -  if (HeaderSize > 0) {
> -//
> -// Skip header size
> -//
> -for (; Index < BlockMap->NumBlocks && HeaderSize >= BlockMap->Length;
> Index ++) {
> -  HeaderSize -= BlockMap->Length;
> -  LbaIndex ++;
> -}
> -
> -//
> -// Check whether FvHeader is crossing the multi block range.
> -//
> -if (Index >= BlockMap->NumBlocks) {
> -  BlockMap++;
> -  continue;
> -} else if (HeaderSize > 0) {
> -  LbaOffset = HeaderSize;
> -  Size = BlockMap->Length - HeaderSize;
> -  HeaderSize = 0;
> -}
> -  }
> -

[edk2] [PATCH 2/3] MdeModulePkg/DxeCore: Ensure FfsFileHeader 8 bytes aligned [CVE-2018-3630]

2019-02-26 Thread Jian J Wang
From: Star Zeng 

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=864

To follow PI spec, ensure FfsFileHeader 8 bytes aligned.

For the integrity of FV(especially non-MemoryMapped FV) layout,
let CachedFv point to FV beginning, but not (FV + FV header).

And current code only handles (FwVolHeader->ExtHeaderOffset != 0) path,
update code to also handle (FwVolHeader->ExtHeaderOffset == 0) path.

Cc: Jiewen Yao 
Cc: Liming Gao 
Cc: Jian J Wang 
Cc: Hao Wu 
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng 
---
 MdeModulePkg/Core/Dxe/FwVol/FwVol.c | 65 +++--
 1 file changed, 14 insertions(+), 51 deletions(-)

diff --git a/MdeModulePkg/Core/Dxe/FwVol/FwVol.c 
b/MdeModulePkg/Core/Dxe/FwVol/FwVol.c
index 93ddcc3591..28fce46a95 100644
--- a/MdeModulePkg/Core/Dxe/FwVol/FwVol.c
+++ b/MdeModulePkg/Core/Dxe/FwVol/FwVol.c
@@ -3,7 +3,7 @@
   Layers on top of Firmware Block protocol to produce a file abstraction
   of FV based files.
 
-Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
+Copyright (c) 2006 - 2019, 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
@@ -329,8 +329,6 @@ FvCheck (
   FFS_FILE_LIST_ENTRY   *FfsFileEntry;
   EFI_FFS_FILE_HEADER   *FfsHeader;
   UINT8 *CacheLocation;
-  UINTN LbaOffset;
-  UINTN HeaderSize;
   UINTN Index;
   EFI_LBA   LbaIndex;
   UINTN Size;
@@ -353,11 +351,7 @@ FvCheck (
 return Status;
   }
 
-  //
-  // Size is the size of the FV minus the head. We have already allocated
-  // the header to check to make sure the volume is valid
-  //
-  Size = (UINTN)(FwVolHeader->FvLength - FwVolHeader->HeaderLength);
+  Size = (UINTN) FwVolHeader->FvLength;
   if ((FvbAttributes & EFI_FVB2_MEMORY_MAPPED) != 0) {
 FvDevice->IsMemoryMapped = TRUE;
 
@@ -369,7 +363,7 @@ FvCheck (
 //
 // Don't cache memory mapped FV really.
 //
-FvDevice->CachedFv = (UINT8 *) (UINTN) (PhysicalAddress + 
FwVolHeader->HeaderLength);
+FvDevice->CachedFv = (UINT8 *) (UINTN) PhysicalAddress;
   } else {
 FvDevice->IsMemoryMapped = FALSE;
 FvDevice->CachedFv = AllocatePool (Size);
@@ -380,52 +374,27 @@ FvCheck (
   }
 
   //
-  // Remember a pointer to the end fo the CachedFv
+  // Remember a pointer to the end of the CachedFv
   //
   FvDevice->EndOfCachedFv = FvDevice->CachedFv + Size;
 
   if (!FvDevice->IsMemoryMapped) {
 //
-// Copy FV minus header into memory using the block map we have all ready
-// read into memory.
+// Copy FV into memory using the block map.
 //
 BlockMap = FwVolHeader->BlockMap;
 CacheLocation = FvDevice->CachedFv;
 LbaIndex = 0;
-LbaOffset = 0;
-HeaderSize = FwVolHeader->HeaderLength;
 while ((BlockMap->NumBlocks != 0) || (BlockMap->Length != 0)) {
-  Index = 0;
-  Size  = BlockMap->Length;
-  if (HeaderSize > 0) {
-//
-// Skip header size
-//
-for (; Index < BlockMap->NumBlocks && HeaderSize >= BlockMap->Length; 
Index ++) {
-  HeaderSize -= BlockMap->Length;
-  LbaIndex ++;
-}
-
-//
-// Check whether FvHeader is crossing the multi block range.
-//
-if (Index >= BlockMap->NumBlocks) {
-  BlockMap++;
-  continue;
-} else if (HeaderSize > 0) {
-  LbaOffset = HeaderSize;
-  Size = BlockMap->Length - HeaderSize;
-  HeaderSize = 0;
-}
-  }
-
   //
   // read the FV data
   //
-  for (; Index < BlockMap->NumBlocks; Index ++) {
-Status = Fvb->Read (Fvb,
+  Size = BlockMap->Length;
+  for (Index = 0; Index < BlockMap->NumBlocks; Index++) {
+Status = Fvb->Read (
+Fvb,
 LbaIndex,
-LbaOffset,
+0,
 ,
 CacheLocation
 );
@@ -438,13 +407,7 @@ FvCheck (
 }
 
 LbaIndex++;
-CacheLocation += Size;
-
-//
-// After we skip Fv Header always read from start of block
-//
-LbaOffset = 0;
-Size  = BlockMap->Length;
+CacheLocation += BlockMap->Length;
   }
 
   BlockMap++;
@@ -475,12 +438,12 @@ FvCheck (
 //
 // Searching for files starts on an 8 byte aligned boundary after the end 
of the Extended Header if it exists.
 //
-FwVolExtHeader = (EFI_FIRMWARE_VOLUME_EXT_HEADER *) (FvDevice->CachedFv + 
(FwVolHeader->ExtHeaderOffset - FwVolHeader->HeaderLength));
+FwVolExtHeader =