Security enhancement to SMM Base thunk drivers: Framework SMM drivers can't be loaded after SMRAM is locked.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10316 6f19259b-4bc3-4df7-8a09-765794883524

2 files changed, 58 insertions, 8 deletions

diff --git a/EdkCompatibilityPkg/Compatibility/SmmBaseHelper/SmmBaseHelper.c b/EdkCompatibilityPkg/Compatibility/SmmBaseHelper/SmmBaseHelper.c
index 033d93eff8..e7976b9c0c 100644
--- a/EdkCompatibilityPkg/Compatibility/SmmBaseHelper/SmmBaseHelper.c
+++ b/EdkCompatibilityPkg/Compatibility/SmmBaseHelper/SmmBaseHelper.c
@@ -32,6 +32,7 @@
 #include <Protocol/SmmCpuSaveState.h>

 #include <Protocol/MpService.h>

 #include <Protocol/LoadPe32Image.h>

+#include <Protocol/SmmReadyToLock.h>

 

 ///

 /// Structure for tracking paired information of registered Framework SMI handler

@@ -67,6 +68,7 @@ EFI_GUID                           mEfiSmmCpuIoGuid = EFI_SMM_CPU_IO_GUID;
 EFI_SMM_BASE_HELPER_READY_PROTOCOL *mSmmBaseHelperReady;

 EFI_SMM_SYSTEM_TABLE               *mFrameworkSmst;

 UINTN                              mNumberOfProcessors;

+BOOLEAN                            mLocked = FALSE;

 

 LIST_ENTRY mCallbackInfoListHead = INITIALIZE_LIST_HEAD_VARIABLE (mCallbackInfoListHead);

 

@@ -272,7 +274,7 @@ Register (
 {

   EFI_STATUS Status;

 

-  if (FunctionData->Args.Register.LegacyIA32Binary) {

+  if (mLocked || FunctionData->Args.Register.LegacyIA32Binary) {

     Status = EFI_UNSUPPORTED;

   } else {

     Status = LoadImage (

@@ -463,6 +465,11 @@ RegisterCallback (
 {

   CALLBACK_INFO  *Buffer;

 

+  if (mLocked) {

+    FunctionData->Status = EFI_UNSUPPORTED;

+    return;

+  }

+

   ///

   /// Note that MakeLast and FloatingPointSave options are not supported in PI SMM

   ///

@@ -512,11 +519,15 @@ HelperAllocatePool (
   IN OUT SMMBASE_FUNCTION_DATA *FunctionData

   )

 {

-  FunctionData->Status = gSmst->SmmAllocatePool (

-                                  FunctionData->Args.AllocatePool.PoolType,

-                                  FunctionData->Args.AllocatePool.Size,

-                                  FunctionData->Args.AllocatePool.Buffer

-                                  );

+  if (mLocked) {

+    FunctionData->Status =  EFI_UNSUPPORTED;

+  } else {

+    FunctionData->Status = gSmst->SmmAllocatePool (

+                                    FunctionData->Args.AllocatePool.PoolType,

+                                    FunctionData->Args.AllocatePool.Size,

+                                    FunctionData->Args.AllocatePool.Buffer

+                                    );

+  }

 }

 

 /** 

@@ -529,8 +540,12 @@ HelperFreePool (
   IN OUT SMMBASE_FUNCTION_DATA *FunctionData

   )

 {

-  FreePool (FunctionData->Args.FreePool.Buffer);

-  FunctionData->Status = EFI_SUCCESS;

+  if (mLocked) {

+    FunctionData->Status =  EFI_UNSUPPORTED;

+  } else {

+    FreePool (FunctionData->Args.FreePool.Buffer);

+    FunctionData->Status = EFI_SUCCESS;

+  }

 }

 

 /** 

@@ -634,6 +649,29 @@ SmmHandlerEntry (
 }

 

 /**

+  Smm Ready To Lock event notification handler.

+

+  It sets a flag indicating that SMRAM has been locked.

+  

+  @param[in] Protocol   Points to the protocol's unique identifier.

+  @param[in] Interface  Points to the interface instance.

+  @param[in] Handle     The handle on which the interface was installed.

+

+  @retval EFI_SUCCESS   Notification handler runs successfully.

+ **/

+EFI_STATUS

+EFIAPI

+SmmReadyToLockEventNotify (

+  IN CONST EFI_GUID  *Protocol,

+  IN VOID            *Interface,

+  IN EFI_HANDLE      Handle

+  )

+{

+  mLocked = TRUE;

+  return EFI_SUCCESS;

+}

+

+/**

   Entry point function of the SMM Base Helper SMM driver.

 

   @param[in] ImageHandle  The firmware allocated handle for the EFI image.  

@@ -653,6 +691,7 @@ SmmBaseHelperMain (
   EFI_MP_SERVICES_PROTOCOL   *MpServices;

   EFI_HANDLE                 Handle;

   UINTN                      NumberOfEnabledProcessors;

+  VOID                       *Registration;

   

   Handle = NULL;

   ///

@@ -697,6 +736,16 @@ SmmBaseHelperMain (
   mSmmBaseHelperReady->FrameworkSmst = mFrameworkSmst;

   mSmmBaseHelperReady->ServiceEntry = SmmHandlerEntry;

 

+  //

+  // Register SMM Ready To Lock Protocol notification

+  //

+  Status = gSmst->SmmRegisterProtocolNotify (

+                    &gEfiSmmReadyToLockProtocolGuid,

+                    SmmReadyToLockEventNotify,

+                    &Registration

+                    );

+  ASSERT_EFI_ERROR (Status);

+

   ///

   /// Register SMM Base Helper services for SMM Base Thunk driver

   ///

diff --git a/EdkCompatibilityPkg/Compatibility/SmmBaseHelper/SmmBaseHelper.inf b/EdkCompatibilityPkg/Compatibility/SmmBaseHelper/SmmBaseHelper.inf
index e4c0f42bd6..88e7f0a588 100644
--- a/EdkCompatibilityPkg/Compatibility/SmmBaseHelper/SmmBaseHelper.inf
+++ b/EdkCompatibilityPkg/Compatibility/SmmBaseHelper/SmmBaseHelper.inf
@@ -59,6 +59,7 @@
   gEfiMpServiceProtocolGuid              # PROTOCOL ALWAYS_CONSUMED

   gEfiSmmCpuIo2ProtocolGuid              # PROTOCOL ALWAYS_CONSUMED

   gEfiLoadPeImageProtocolGuid            # PROTOCOL ALWAYS_CONSUMED

+  gEfiSmmReadyToLockProtocolGuid         # PROTOCOL ALWAYS_CONSUMED

 

 [Depex]

   gEfiSmmCpuProtocolGuid AND