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/** @file
LockBox SMM driver.
Caution: This module requires additional review when modified.
This driver will have external input - communicate buffer in SMM mode.
This external input must be validated carefully to avoid security issue like
buffer overflow, integer overflow.
SmmLockBoxHandler(), SmmLockBoxRestore(), SmmLockBoxUpdate(), SmmLockBoxSave()
will receive untrusted input and do basic validation.
Copyright (c) 2010 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <PiSmm.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiRuntimeServicesTableLib.h>
#include <Library/SmmServicesTableLib.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/SmmMemLib.h>
#include <Library/LockBoxLib.h>
#include <Protocol/SmmReadyToLock.h>
#include <Protocol/SmmCommunication.h>
#include <Protocol/LockBox.h>
#include <Guid/SmmLockBox.h>
BOOLEAN mLocked = FALSE;
/**
Dispatch function for SMM lock box save.
Caution: This function may receive untrusted input.
Restore buffer and length are external input, so this function will validate
it is in SMRAM.
@param LockBoxParameterSave parameter of lock box save
**/
VOID
SmmLockBoxSave (
IN EFI_SMM_LOCK_BOX_PARAMETER_SAVE *LockBoxParameterSave
)
{
EFI_STATUS Status;
EFI_SMM_LOCK_BOX_PARAMETER_SAVE TempLockBoxParameterSave;
//
// Sanity check
//
if (mLocked) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Locked!\n"));
LockBoxParameterSave->Header.ReturnStatus = (UINT64)EFI_ACCESS_DENIED;
return;
}
CopyMem (&TempLockBoxParameterSave, LockBoxParameterSave, sizeof (EFI_SMM_LOCK_BOX_PARAMETER_SAVE));
//
// Sanity check
//
if (!SmmIsBufferOutsideSmmValid ((UINTN)TempLockBoxParameterSave.Buffer, (UINTN)TempLockBoxParameterSave.Length)) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Save address in SMRAM or buffer overflow!\n"));
LockBoxParameterSave->Header.ReturnStatus = (UINT64)EFI_ACCESS_DENIED;
return;
}
//
// The SpeculationBarrier() call here is to ensure the above range check for
// the CommBuffer have been completed before calling into SaveLockBox().
//
SpeculationBarrier ();
//
// Save data
//
Status = SaveLockBox (
&TempLockBoxParameterSave.Guid,
(VOID *)(UINTN)TempLockBoxParameterSave.Buffer,
(UINTN)TempLockBoxParameterSave.Length
);
LockBoxParameterSave->Header.ReturnStatus = (UINT64)Status;
return;
}
/**
Dispatch function for SMM lock box set attributes.
@param LockBoxParameterSetAttributes parameter of lock box set attributes
**/
VOID
SmmLockBoxSetAttributes (
IN EFI_SMM_LOCK_BOX_PARAMETER_SET_ATTRIBUTES *LockBoxParameterSetAttributes
)
{
EFI_STATUS Status;
EFI_SMM_LOCK_BOX_PARAMETER_SET_ATTRIBUTES TempLockBoxParameterSetAttributes;
//
// Sanity check
//
if (mLocked) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Locked!\n"));
LockBoxParameterSetAttributes->Header.ReturnStatus = (UINT64)EFI_ACCESS_DENIED;
return;
}
CopyMem (&TempLockBoxParameterSetAttributes, LockBoxParameterSetAttributes, sizeof (EFI_SMM_LOCK_BOX_PARAMETER_SET_ATTRIBUTES));
//
// Update data
//
Status = SetLockBoxAttributes (
&TempLockBoxParameterSetAttributes.Guid,
TempLockBoxParameterSetAttributes.Attributes
);
LockBoxParameterSetAttributes->Header.ReturnStatus = (UINT64)Status;
return;
}
/**
Dispatch function for SMM lock box update.
Caution: This function may receive untrusted input.
Restore buffer and length are external input, so this function will validate
it is in SMRAM.
@param LockBoxParameterUpdate parameter of lock box update
**/
VOID
SmmLockBoxUpdate (
IN EFI_SMM_LOCK_BOX_PARAMETER_UPDATE *LockBoxParameterUpdate
)
{
EFI_STATUS Status;
EFI_SMM_LOCK_BOX_PARAMETER_UPDATE TempLockBoxParameterUpdate;
//
// Sanity check
//
if (mLocked) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Locked!\n"));
LockBoxParameterUpdate->Header.ReturnStatus = (UINT64)EFI_ACCESS_DENIED;
return;
}
CopyMem (&TempLockBoxParameterUpdate, LockBoxParameterUpdate, sizeof (EFI_SMM_LOCK_BOX_PARAMETER_UPDATE));
//
// Sanity check
//
if (!SmmIsBufferOutsideSmmValid ((UINTN)TempLockBoxParameterUpdate.Buffer, (UINTN)TempLockBoxParameterUpdate.Length)) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Update address in SMRAM or buffer overflow!\n"));
LockBoxParameterUpdate->Header.ReturnStatus = (UINT64)EFI_ACCESS_DENIED;
return;
}
//
// The SpeculationBarrier() call here is to ensure the above range check for
// the CommBuffer have been completed before calling into UpdateLockBox().
//
SpeculationBarrier ();
//
// Update data
//
Status = UpdateLockBox (
&TempLockBoxParameterUpdate.Guid,
(UINTN)TempLockBoxParameterUpdate.Offset,
(VOID *)(UINTN)TempLockBoxParameterUpdate.Buffer,
(UINTN)TempLockBoxParameterUpdate.Length
);
LockBoxParameterUpdate->Header.ReturnStatus = (UINT64)Status;
return;
}
/**
Dispatch function for SMM lock box restore.
Caution: This function may receive untrusted input.
Restore buffer and length are external input, so this function will validate
it is in SMRAM.
@param LockBoxParameterRestore parameter of lock box restore
**/
VOID
SmmLockBoxRestore (
IN EFI_SMM_LOCK_BOX_PARAMETER_RESTORE *LockBoxParameterRestore
)
{
EFI_STATUS Status;
EFI_SMM_LOCK_BOX_PARAMETER_RESTORE TempLockBoxParameterRestore;
CopyMem (&TempLockBoxParameterRestore, LockBoxParameterRestore, sizeof (EFI_SMM_LOCK_BOX_PARAMETER_RESTORE));
//
// Sanity check
//
if (!SmmIsBufferOutsideSmmValid ((UINTN)TempLockBoxParameterRestore.Buffer, (UINTN)TempLockBoxParameterRestore.Length)) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Restore address in SMRAM or buffer overflow!\n"));
LockBoxParameterRestore->Header.ReturnStatus = (UINT64)EFI_ACCESS_DENIED;
return;
}
//
// Restore data
//
if ((TempLockBoxParameterRestore.Length == 0) && (TempLockBoxParameterRestore.Buffer == 0)) {
Status = RestoreLockBox (
&TempLockBoxParameterRestore.Guid,
NULL,
NULL
);
} else {
Status = RestoreLockBox (
&TempLockBoxParameterRestore.Guid,
(VOID *)(UINTN)TempLockBoxParameterRestore.Buffer,
(UINTN *)&TempLockBoxParameterRestore.Length
);
if ((Status == EFI_BUFFER_TOO_SMALL) || (Status == EFI_SUCCESS)) {
//
// Return the actual Length value.
//
LockBoxParameterRestore->Length = TempLockBoxParameterRestore.Length;
}
}
LockBoxParameterRestore->Header.ReturnStatus = (UINT64)Status;
return;
}
/**
Dispatch function for SMM lock box restore all in place.
@param LockBoxParameterRestoreAllInPlace parameter of lock box restore all in place
**/
VOID
SmmLockBoxRestoreAllInPlace (
IN EFI_SMM_LOCK_BOX_PARAMETER_RESTORE_ALL_IN_PLACE *LockBoxParameterRestoreAllInPlace
)
{
EFI_STATUS Status;
Status = RestoreAllLockBoxInPlace ();
LockBoxParameterRestoreAllInPlace->Header.ReturnStatus = (UINT64)Status;
return;
}
/**
Dispatch function for a Software SMI handler.
Caution: This function may receive untrusted input.
Communicate buffer and buffer size are external input, so this function will do basic validation.
@param DispatchHandle The unique handle assigned to this handler by SmiHandlerRegister().
@param Context Points to an optional handler context which was specified when the
handler was registered.
@param CommBuffer A pointer to a collection of data in memory that will
be conveyed from a non-SMM environment into an SMM environment.
@param CommBufferSize The size of the CommBuffer.
@retval EFI_SUCCESS Command is handled successfully.
**/
EFI_STATUS
EFIAPI
SmmLockBoxHandler (
IN EFI_HANDLE DispatchHandle,
IN CONST VOID *Context OPTIONAL,
IN OUT VOID *CommBuffer OPTIONAL,
IN OUT UINTN *CommBufferSize OPTIONAL
)
{
EFI_SMM_LOCK_BOX_PARAMETER_HEADER *LockBoxParameterHeader;
UINTN TempCommBufferSize;
DEBUG ((DEBUG_INFO, "SmmLockBox SmmLockBoxHandler Enter\n"));
//
// If input is invalid, stop processing this SMI
//
if ((CommBuffer == NULL) || (CommBufferSize == NULL)) {
return EFI_SUCCESS;
}
TempCommBufferSize = *CommBufferSize;
//
// Sanity check
//
if (TempCommBufferSize < sizeof (EFI_SMM_LOCK_BOX_PARAMETER_HEADER)) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Command Buffer Size invalid!\n"));
return EFI_SUCCESS;
}
if (!SmmIsBufferOutsideSmmValid ((UINTN)CommBuffer, TempCommBufferSize)) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Command Buffer in SMRAM or overflow!\n"));
return EFI_SUCCESS;
}
LockBoxParameterHeader = (EFI_SMM_LOCK_BOX_PARAMETER_HEADER *)((UINTN)CommBuffer);
LockBoxParameterHeader->ReturnStatus = (UINT64)-1;
DEBUG ((DEBUG_INFO, "SmmLockBox LockBoxParameterHeader - %x\n", (UINTN)LockBoxParameterHeader));
DEBUG ((DEBUG_INFO, "SmmLockBox Command - %x\n", (UINTN)LockBoxParameterHeader->Command));
switch (LockBoxParameterHeader->Command) {
case EFI_SMM_LOCK_BOX_COMMAND_SAVE:
if (TempCommBufferSize < sizeof (EFI_SMM_LOCK_BOX_PARAMETER_SAVE)) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Command Buffer Size for SAVE invalid!\n"));
break;
}
SmmLockBoxSave ((EFI_SMM_LOCK_BOX_PARAMETER_SAVE *)(UINTN)LockBoxParameterHeader);
break;
case EFI_SMM_LOCK_BOX_COMMAND_UPDATE:
if (TempCommBufferSize < sizeof (EFI_SMM_LOCK_BOX_PARAMETER_UPDATE)) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Command Buffer Size for UPDATE invalid!\n"));
break;
}
SmmLockBoxUpdate ((EFI_SMM_LOCK_BOX_PARAMETER_UPDATE *)(UINTN)LockBoxParameterHeader);
break;
case EFI_SMM_LOCK_BOX_COMMAND_RESTORE:
if (TempCommBufferSize < sizeof (EFI_SMM_LOCK_BOX_PARAMETER_RESTORE)) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Command Buffer Size for RESTORE invalid!\n"));
break;
}
SmmLockBoxRestore ((EFI_SMM_LOCK_BOX_PARAMETER_RESTORE *)(UINTN)LockBoxParameterHeader);
break;
case EFI_SMM_LOCK_BOX_COMMAND_SET_ATTRIBUTES:
if (TempCommBufferSize < sizeof (EFI_SMM_LOCK_BOX_PARAMETER_SET_ATTRIBUTES)) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Command Buffer Size for SET_ATTRIBUTES invalid!\n"));
break;
}
SmmLockBoxSetAttributes ((EFI_SMM_LOCK_BOX_PARAMETER_SET_ATTRIBUTES *)(UINTN)LockBoxParameterHeader);
break;
case EFI_SMM_LOCK_BOX_COMMAND_RESTORE_ALL_IN_PLACE:
if (TempCommBufferSize < sizeof (EFI_SMM_LOCK_BOX_PARAMETER_RESTORE_ALL_IN_PLACE)) {
DEBUG ((DEBUG_ERROR, "SmmLockBox Command Buffer Size for RESTORE_ALL_IN_PLACE invalid!\n"));
break;
}
SmmLockBoxRestoreAllInPlace ((EFI_SMM_LOCK_BOX_PARAMETER_RESTORE_ALL_IN_PLACE *)(UINTN)LockBoxParameterHeader);
break;
default:
DEBUG ((DEBUG_ERROR, "SmmLockBox Command invalid!\n"));
break;
}
LockBoxParameterHeader->Command = (UINT32)-1;
DEBUG ((DEBUG_INFO, "SmmLockBox SmmLockBoxHandler Exit\n"));
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 for LockBox SMM driver.
@param[in] ImageHandle Image handle of this driver.
@param[in] SystemTable A Pointer to the EFI System Table.
@retval EFI_SUCEESS
@return Others Some error occurs.
**/
EFI_STATUS
EFIAPI
SmmLockBoxEntryPoint (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
EFI_HANDLE DispatchHandle;
VOID *Registration;
//
// Register LockBox communication handler
//
Status = gSmst->SmiHandlerRegister (
SmmLockBoxHandler,
&gEfiSmmLockBoxCommunicationGuid,
&DispatchHandle
);
ASSERT_EFI_ERROR (Status);
//
// Register SMM Ready To Lock Protocol notification
//
Status = gSmst->SmmRegisterProtocolNotify (
&gEfiSmmReadyToLockProtocolGuid,
SmmReadyToLockEventNotify,
&Registration
);
ASSERT_EFI_ERROR (Status);
//
// Install NULL to DXE data base as notify
//
ImageHandle = NULL;
Status = gBS->InstallProtocolInterface (
&ImageHandle,
&gEfiLockBoxProtocolGuid,
EFI_NATIVE_INTERFACE,
NULL
);
ASSERT_EFI_ERROR (Status);
return Status;
}