SecurityPkg: Variable drivers robustly handle crashes during Reclaim().

PEI variable implementation checks only the variable header signature for validity. This does not seem robust if system crash occurred during previous Reclaim() operation. If the crash occurred while FTW was rewriting the variable FV, the signature could be valid even though the rest of the FV isn't valid.
Solution: PEI variable and early phase(before FTW protocol ready) of DXE variable can check the FTW last write status provided by FaultTolerantWritePei and determine if all or partial variable data has been backed up in spare block, and then use the backed up data.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14455 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 150 insertions, 81 deletions

diff --git a/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c b/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c
index 576623e88b..ef123d2d5c 100644
--- a/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c
+++ b/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c
@@ -3069,6 +3069,135 @@ ReclaimForOS(
 }

 

 /**

+  Init non-volatile variable store.

+

+  @retval EFI_SUCCESS           Function successfully executed.

+  @retval EFI_OUT_OF_RESOURCES  Fail to allocate enough memory resource.

+  @retval EFI_VOLUME_CORRUPTED  Variable Store or Firmware Volume for Variable Store is corrupted.

+

+**/

+EFI_STATUS

+InitNonVolatileVariableStore (

+  VOID

+  )

+{

+  EFI_FIRMWARE_VOLUME_HEADER            *FvHeader;

+  VARIABLE_HEADER                       *NextVariable;

+  EFI_PHYSICAL_ADDRESS                  VariableStoreBase;

+  UINT64                                VariableStoreLength;

+  UINTN                                 VariableSize;

+  EFI_HOB_GUID_TYPE                     *GuidHob;

+  EFI_PHYSICAL_ADDRESS                  NvStorageBase;

+  UINT8                                 *NvStorageData;

+  UINT32                                NvStorageSize;

+  FAULT_TOLERANT_WRITE_LAST_WRITE_DATA  *FtwLastWriteData;

+  UINT32                                BackUpOffset;

+  UINT32                                BackUpSize;

+

+  mVariableModuleGlobal->FvbInstance = NULL;

+

+  //

+  // Note that in EdkII variable driver implementation, Hardware Error Record type variable

+  // is stored with common variable in the same NV region. So the platform integrator should

+  // ensure that the value of PcdHwErrStorageSize is less than or equal to the value of

+  // PcdFlashNvStorageVariableSize.

+  //

+  ASSERT (PcdGet32 (PcdHwErrStorageSize) <= PcdGet32 (PcdFlashNvStorageVariableSize));

+

+  //

+  // Allocate runtime memory used for a memory copy of the FLASH region.

+  // Keep the memory and the FLASH in sync as updates occur.

+  //

+  NvStorageSize = PcdGet32 (PcdFlashNvStorageVariableSize);

+  NvStorageData = AllocateRuntimeZeroPool (NvStorageSize);

+  if (NvStorageData == NULL) {

+    return EFI_OUT_OF_RESOURCES;

+  }

+

+  NvStorageBase = (EFI_PHYSICAL_ADDRESS) PcdGet64 (PcdFlashNvStorageVariableBase64);

+  if (NvStorageBase == 0) {

+    NvStorageBase = (EFI_PHYSICAL_ADDRESS) PcdGet32 (PcdFlashNvStorageVariableBase);

+  }

+  //

+  // Copy NV storage data to the memory buffer.

+  //

+  CopyMem (NvStorageData, (UINT8 *) (UINTN) NvStorageBase, NvStorageSize);

+

+  //

+  // Check the FTW last write data hob.

+  //

+  GuidHob = GetFirstGuidHob (&gEdkiiFaultTolerantWriteGuid);

+  if (GuidHob != NULL) {

+    FtwLastWriteData = (FAULT_TOLERANT_WRITE_LAST_WRITE_DATA *) GET_GUID_HOB_DATA (GuidHob);

+    if (FtwLastWriteData->TargetAddress == NvStorageBase) {

+      DEBUG ((EFI_D_INFO, "Variable: NV storage is backed up in spare block: 0x%x\n", (UINTN) FtwLastWriteData->SpareAddress));

+      //

+      // Copy the backed up NV storage data to the memory buffer from spare block.

+      //

+      CopyMem (NvStorageData, (UINT8 *) (UINTN) (FtwLastWriteData->SpareAddress), NvStorageSize);

+    } else if ((FtwLastWriteData->TargetAddress > NvStorageBase) &&

+               (FtwLastWriteData->TargetAddress < (NvStorageBase + NvStorageSize))) {

+      //

+      // Flash NV storage from the Offset is backed up in spare block.

+      //

+      BackUpOffset = (UINT32) (FtwLastWriteData->TargetAddress - NvStorageBase);

+      BackUpSize = NvStorageSize - BackUpOffset;

+      DEBUG ((EFI_D_INFO, "Variable: High partial NV storage from offset: %x is backed up in spare block: 0x%x\n", BackUpOffset, (UINTN) FtwLastWriteData->SpareAddress));

+      //

+      // Copy the partial backed up NV storage data to the memory buffer from spare block.

+      //

+      CopyMem (NvStorageData + BackUpOffset, (UINT8 *) (UINTN) FtwLastWriteData->SpareAddress, BackUpSize);

+    }

+  }

+

+  FvHeader = (EFI_FIRMWARE_VOLUME_HEADER *) NvStorageData;

+

+  //

+  // Check if the Firmware Volume is not corrupted

+  //

+  if ((FvHeader->Signature != EFI_FVH_SIGNATURE) || (!CompareGuid (&gEfiSystemNvDataFvGuid, &FvHeader->FileSystemGuid))) {

+    FreePool (NvStorageData);

+    DEBUG ((EFI_D_ERROR, "Firmware Volume for Variable Store is corrupted\n"));

+    return EFI_VOLUME_CORRUPTED;

+  }

+

+  VariableStoreBase = (EFI_PHYSICAL_ADDRESS) ((UINTN) FvHeader + FvHeader->HeaderLength);

+  VariableStoreLength = (UINT64) (NvStorageSize - FvHeader->HeaderLength);

+

+  mVariableModuleGlobal->VariableGlobal.NonVolatileVariableBase = VariableStoreBase;

+  mNvVariableCache = (VARIABLE_STORE_HEADER *) (UINTN) VariableStoreBase;

+  if (GetVariableStoreStatus (mNvVariableCache) != EfiValid) {

+    FreePool (NvStorageData);

+    DEBUG((EFI_D_ERROR, "Variable Store header is corrupted\n"));

+    return EFI_VOLUME_CORRUPTED;

+  }

+  ASSERT(mNvVariableCache->Size == VariableStoreLength);

+

+  //

+  // The max variable or hardware error variable size should be < variable store size.

+  //

+  ASSERT(MAX (PcdGet32 (PcdMaxVariableSize), PcdGet32 (PcdMaxHardwareErrorVariableSize)) < VariableStoreLength);

+

+  //

+  // Parse non-volatile variable data and get last variable offset.

+  //

+  NextVariable  = GetStartPointer ((VARIABLE_STORE_HEADER *)(UINTN)VariableStoreBase);

+  while (IsValidVariableHeader (NextVariable)) {

+    VariableSize = NextVariable->NameSize + NextVariable->DataSize + sizeof (VARIABLE_HEADER);

+    if ((NextVariable->Attributes & (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_HARDWARE_ERROR_RECORD)) == (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_HARDWARE_ERROR_RECORD)) {

+      mVariableModuleGlobal->HwErrVariableTotalSize += HEADER_ALIGN (VariableSize);

+    } else {

+      mVariableModuleGlobal->CommonVariableTotalSize += HEADER_ALIGN (VariableSize);

+    }

+

+    NextVariable = GetNextVariablePtr (NextVariable);

+  }

+  mVariableModuleGlobal->NonVolatileLastVariableOffset = (UINTN) NextVariable - (UINTN) VariableStoreBase;

+

+  return EFI_SUCCESS;

+}

+

+/**

   Flush the HOB variable to flash.

 

   @param[in] VariableName       Name of variable has been updated or deleted.

@@ -3159,7 +3288,7 @@ FlushHobVariableToFlash (
 }

 

 /**

-  Initializes variable write service after FVB was ready.

+  Initializes variable write service after FTW was ready.

 

   @retval EFI_SUCCESS          Function successfully executed.

   @retval Others               Fail to initialize the variable service.

@@ -3175,8 +3304,18 @@ VariableWriteServiceInitialize (
   UINTN                           Index;

   UINT8                           Data;

   EFI_PHYSICAL_ADDRESS            VariableStoreBase;

+  EFI_PHYSICAL_ADDRESS            NvStorageBase;

+

+  NvStorageBase = (EFI_PHYSICAL_ADDRESS) PcdGet64 (PcdFlashNvStorageVariableBase64);

+  if (NvStorageBase == 0) {

+    NvStorageBase = (EFI_PHYSICAL_ADDRESS) PcdGet32 (PcdFlashNvStorageVariableBase);

+  }

+  VariableStoreBase = NvStorageBase + (((EFI_FIRMWARE_VOLUME_HEADER *)(UINTN)(NvStorageBase))->HeaderLength);

 

-  VariableStoreBase   = mVariableModuleGlobal->VariableGlobal.NonVolatileVariableBase;

+  //

+  // Let NonVolatileVariableBase point to flash variable store base directly after FTW ready.

+  //

+  mVariableModuleGlobal->VariableGlobal.NonVolatileVariableBase = VariableStoreBase;

   VariableStoreHeader = (VARIABLE_STORE_HEADER *)(UINTN)VariableStoreBase;

 

   //

@@ -3229,12 +3368,8 @@ VariableCommonInitialize (
   EFI_STATUS                      Status;

   VARIABLE_STORE_HEADER           *VolatileVariableStore;

   VARIABLE_STORE_HEADER           *VariableStoreHeader;

-  VARIABLE_HEADER                 *NextVariable;

-  EFI_PHYSICAL_ADDRESS            TempVariableStoreHeader;

-  EFI_PHYSICAL_ADDRESS            VariableStoreBase;

   UINT64                          VariableStoreLength;

   UINTN                           ScratchSize;

-  UINTN                           VariableSize;

   EFI_HOB_GUID_TYPE               *GuidHob;

 

   //

@@ -3248,14 +3383,6 @@ VariableCommonInitialize (
   InitializeLock (&mVariableModuleGlobal->VariableGlobal.VariableServicesLock, TPL_NOTIFY);

 

   //

-  // Note that in EdkII variable driver implementation, Hardware Error Record type variable

-  // is stored with common variable in the same NV region. So the platform integrator should

-  // ensure that the value of PcdHwErrStorageSize is less than or equal to the value of

-  // PcdFlashNvStorageVariableSize.

-  //

-  ASSERT (PcdGet32 (PcdHwErrStorageSize) <= PcdGet32 (PcdFlashNvStorageVariableSize));

-

-  //

   // Get HOB variable store.

   //

   GuidHob = GetFirstGuidHob (&gEfiAuthenticatedVariableGuid);

@@ -3265,6 +3392,7 @@ VariableCommonInitialize (
     if (GetVariableStoreStatus (VariableStoreHeader) == EfiValid) {

       mVariableModuleGlobal->VariableGlobal.HobVariableBase = (EFI_PHYSICAL_ADDRESS) (UINTN) AllocateRuntimeCopyPool ((UINTN) VariableStoreLength, (VOID *) VariableStoreHeader);

       if (mVariableModuleGlobal->VariableGlobal.HobVariableBase == 0) {

+        FreePool (mVariableModuleGlobal);

         return EFI_OUT_OF_RESOURCES;

       }

     } else {

@@ -3278,6 +3406,9 @@ VariableCommonInitialize (
   ScratchSize = MAX (PcdGet32 (PcdMaxVariableSize), PcdGet32 (PcdMaxHardwareErrorVariableSize));

   VolatileVariableStore = AllocateRuntimePool (PcdGet32 (PcdVariableStoreSize) + ScratchSize);

   if (VolatileVariableStore == NULL) {

+    if (mVariableModuleGlobal->VariableGlobal.HobVariableBase != 0) {

+      FreePool ((VOID *) (UINTN) mVariableModuleGlobal->VariableGlobal.HobVariableBase);

+    }

     FreePool (mVariableModuleGlobal);

     return EFI_OUT_OF_RESOURCES;

   }

@@ -3289,7 +3420,6 @@ VariableCommonInitialize (
   //

   mVariableModuleGlobal->VariableGlobal.VolatileVariableBase = (EFI_PHYSICAL_ADDRESS) (UINTN) VolatileVariableStore;

   mVariableModuleGlobal->VolatileLastVariableOffset = (UINTN) GetStartPointer (VolatileVariableStore) - (UINTN) VolatileVariableStore;

-  mVariableModuleGlobal->FvbInstance = NULL;

 

   CopyGuid (&VolatileVariableStore->Signature, &gEfiAuthenticatedVariableGuid);

   VolatileVariableStore->Size        = PcdGet32 (PcdVariableStoreSize);

@@ -3299,74 +3429,13 @@ VariableCommonInitialize (
   VolatileVariableStore->Reserved1   = 0;

 

   //

-  // Get non-volatile variable store.

-  //

-

-  TempVariableStoreHeader = (EFI_PHYSICAL_ADDRESS) PcdGet64 (PcdFlashNvStorageVariableBase64);

-  if (TempVariableStoreHeader == 0) {

-    TempVariableStoreHeader = (EFI_PHYSICAL_ADDRESS) PcdGet32 (PcdFlashNvStorageVariableBase);

-  }

-  

-  //

-  // Check if the Firmware Volume is not corrupted

-  //

-  if ((((EFI_FIRMWARE_VOLUME_HEADER *)(UINTN)(TempVariableStoreHeader))->Signature != EFI_FVH_SIGNATURE) ||

-      (!CompareGuid (&gEfiSystemNvDataFvGuid, &((EFI_FIRMWARE_VOLUME_HEADER *)(UINTN)(TempVariableStoreHeader))->FileSystemGuid))) {

-    Status = EFI_VOLUME_CORRUPTED;

-    DEBUG ((EFI_D_ERROR, "Firmware Volume for Variable Store is corrupted\n"));

-    goto Done;

-  }

-

-  VariableStoreBase       = TempVariableStoreHeader + \

-                              (((EFI_FIRMWARE_VOLUME_HEADER *)(UINTN)(TempVariableStoreHeader)) -> HeaderLength);

-  VariableStoreLength     = (UINT64) PcdGet32 (PcdFlashNvStorageVariableSize) - \

-                              (((EFI_FIRMWARE_VOLUME_HEADER *)(UINTN)(TempVariableStoreHeader)) -> HeaderLength);

-

-  mVariableModuleGlobal->VariableGlobal.NonVolatileVariableBase = VariableStoreBase;

-  VariableStoreHeader = (VARIABLE_STORE_HEADER *)(UINTN)VariableStoreBase;

-  if (GetVariableStoreStatus (VariableStoreHeader) != EfiValid) {

-    Status = EFI_VOLUME_CORRUPTED;

-    DEBUG((EFI_D_INFO, "Variable Store header is corrupted\n"));

-    goto Done;

-  }

-  ASSERT(VariableStoreHeader->Size == VariableStoreLength);

-

-  //

-  // The max variable or hardware error variable size should be < variable store size.

-  //

-  ASSERT(MAX (PcdGet32 (PcdMaxVariableSize), PcdGet32 (PcdMaxHardwareErrorVariableSize)) < VariableStoreLength);

-

-  //

-  // Parse non-volatile variable data and get last variable offset.

+  // Init non-volatile variable store.

   //

-  NextVariable  = GetStartPointer ((VARIABLE_STORE_HEADER *)(UINTN)VariableStoreBase);

-  while (IsValidVariableHeader (NextVariable)) {

-    VariableSize = NextVariable->NameSize + NextVariable->DataSize + sizeof (VARIABLE_HEADER);

-    if ((NextVariable->Attributes & (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_HARDWARE_ERROR_RECORD)) == (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_HARDWARE_ERROR_RECORD)) {

-      mVariableModuleGlobal->HwErrVariableTotalSize += HEADER_ALIGN (VariableSize);

-    } else {

-      mVariableModuleGlobal->CommonVariableTotalSize += HEADER_ALIGN (VariableSize);

-    }

-

-    NextVariable = GetNextVariablePtr (NextVariable);

-  }

-

-  mVariableModuleGlobal->NonVolatileLastVariableOffset = (UINTN) NextVariable - (UINTN) VariableStoreBase;

-

-  //

-  // Allocate runtime memory used for a memory copy of the FLASH region.

-  // Keep the memory and the FLASH in sync as updates occur

-  //

-  mNvVariableCache = AllocateRuntimeZeroPool ((UINTN)VariableStoreLength);

-  if (mNvVariableCache == NULL) {

-    Status = EFI_OUT_OF_RESOURCES;

-    goto Done;

-  }

-  CopyMem (mNvVariableCache, (CHAR8 *)(UINTN)VariableStoreBase, (UINTN)VariableStoreLength);

-  Status = EFI_SUCCESS;

-

-Done:

+  Status = InitNonVolatileVariableStore ();

   if (EFI_ERROR (Status)) {

+    if (mVariableModuleGlobal->VariableGlobal.HobVariableBase != 0) {

+      FreePool ((VOID *) (UINTN) mVariableModuleGlobal->VariableGlobal.HobVariableBase);

+    }

     FreePool (mVariableModuleGlobal);

     FreePool (VolatileVariableStore);

   }