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

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
   )
 {
+  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
   )
 {
+  if (mLocked) {
+    FunctionData->Status =  EFI_UNSUPPORTED;
+  } else {
     FreePool (FunctionData->Args.FreePool.Buffer);
     FunctionData->Status = EFI_SUCCESS;
+  }
 }
 
 /** 
@@ -633,6 +648,29 @@ SmmHandlerEntry (
   return EFI_SUCCESS;
 }
 
+/**
+  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.
 
@@ -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
   ///

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

EdkCompatibilityPkg/Compatibility/SmmBaseOnSmmBase2Thunk/SmmBaseOnSmmBase2Thunk.c

@@ -44,6 +44,7 @@ EFI_HANDLE                         mSmmBaseHandle = NULL;
 EFI_SMM_BASE2_PROTOCOL             *mSmmBase2 = NULL;
 EFI_SMM_COMMUNICATION_PROTOCOL     *mSmmCommunication = NULL;
 EFI_SMM_BASE_HELPER_READY_PROTOCOL *mSmmBaseHelperReady = NULL;
+BOOLEAN                            mAtRuntime = FALSE;
 
 /**
   Determine if in SMM mode.
@@ -133,7 +134,7 @@ SmmBaseRegister (
   IN      BOOLEAN                   LegacyIA32Binary
   )
 {
-  if (LegacyIA32Binary) {
+  if (mAtRuntime || LegacyIA32Binary) {
     return EFI_UNSUPPORTED;
   }
 
@@ -166,6 +167,10 @@ SmmBaseUnregister (
   IN      EFI_HANDLE                ImageHandle
   )
 {
+  if (mAtRuntime) {
+    return EFI_UNSUPPORTED;
+  }
+
   mCommunicationData.FunctionData.Function = SmmBaseFunctionUnregister;
   mCommunicationData.FunctionData.Args.UnRegister.ImageHandle = ImageHandle;
 
@@ -308,6 +313,10 @@ SmmBaseSmmAllocatePool (
   OUT     VOID                      **Buffer
   )
 {
+  if (mAtRuntime) {
+    return EFI_UNSUPPORTED;
+  }
+
   mCommunicationData.FunctionData.Function = SmmBaseFunctionAllocatePool;
   mCommunicationData.FunctionData.Args.AllocatePool.PoolType = PoolType;
   mCommunicationData.FunctionData.Args.AllocatePool.Size = Size;
@@ -336,6 +345,10 @@ SmmBaseSmmFreePool (
   IN      VOID                      *Buffer
   )
 {
+  if (mAtRuntime) {
+    return EFI_UNSUPPORTED;
+  }
+
   mCommunicationData.FunctionData.Function = SmmBaseFunctionFreePool;
   mCommunicationData.FunctionData.Args.FreePool.Buffer = Buffer;
 
@@ -408,6 +421,24 @@ EFI_SMM_BASE_PROTOCOL  mSmmBase = {
   SmmBaseGetSmstLocation
 };
 
+/**
+  Notification function on Exit Boot Services Event.
+
+  This function sets a flag indicating it is in Runtime phase.
+
+  @param  Event        Event whose notification function is being invoked
+  @param  Context      Pointer to the notification function's context
+**/
+VOID
+EFIAPI
+SmmBaseExitBootServicesEventNotify (
+  IN EFI_EVENT  Event,
+  IN VOID       *Context
+  )
+{
+  mAtRuntime = TRUE;
+}
+
 /**
   Entry Point for SMM Base Protocol on SMM Base2 Protocol Thunk driver.
 
@@ -449,6 +480,19 @@ SmmBaseThunkMain (
   Status = gBS->LocateProtocol (&gEfiSmmBaseHelperReadyProtocolGuid, NULL, (VOID **) &mSmmBaseHelperReady);
   ASSERT_EFI_ERROR (Status);
 
+  //
+  // Create event notification on Exit Boot Services event.
+  //
+  Status = gBS->CreateEventEx (
+                  EVT_NOTIFY_SIGNAL,
+                  TPL_NOTIFY,
+                  SmmBaseExitBootServicesEventNotify,
+                  NULL,
+                  &gEfiEventExitBootServicesGuid,
+                  &Event
+                  );
+  ASSERT_EFI_ERROR (Status);
+
   //
   // Create event on SetVirtualAddressMap() to convert mSmmCommunication from a physical address to a virtual address
   //

EdkCompatibilityPkg/Compatibility/SmmBaseOnSmmBase2Thunk/SmmBaseOnSmmBase2Thunk.inf

@@ -44,6 +44,7 @@
 
 [Guids]
   gEfiEventVirtualAddressChangeGuid   # GUID ALWAYS_CONSUMED
+  gEfiEventExitBootServicesGuid       # GUID ALWAYS_CONSUMED
 
 [Protocols]
   gEfiSmmBase2ProtocolGuid            # PROTOCOL ALWAYS_CONSUMED