implements an SMI handler to communicate with the DXE runtime driver \r
to provide variable services.\r
\r
-Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>\r
-This program and the accompanying materials \r
-are licensed and made available under the terms and conditions of the BSD License \r
-which accompanies this distribution. The full text of the license may be found at \r
-http://opensource.org/licenses/bsd-license.php \r
+ Caution: This module requires additional review when modified.\r
+ This driver will have external input - variable data and communicate buffer in SMM mode.\r
+ This external input must be validated carefully to avoid security issue like\r
+ buffer overflow, integer overflow.\r
+\r
+ SmmVariableHandler() will receive untrusted input and do basic validation.\r
+\r
+ Each sub function VariableServiceGetVariable(), VariableServiceGetNextVariableName(), \r
+ VariableServiceSetVariable(), VariableServiceQueryVariableInfo(), ReclaimForOS(), \r
+ SmmVariableGetStatistics() should also do validation based on its own knowledge.\r
+\r
+Copyright (c) 2010 - 2012, Intel Corporation. All rights reserved.<BR>\r
+This program and the accompanying materials \r
+are licensed and made available under the terms and conditions of the BSD License \r
+which accompanies this distribution. The full text of the license may be found at \r
+http://opensource.org/licenses/bsd-license.php\r
\r
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r
\r
**/\r
+#include <Protocol/SmmVariable.h>\r
+#include <Protocol/SmmFirmwareVolumeBlock.h>\r
#include <Protocol/SmmFaultTolerantWrite.h>\r
+#include <Protocol/SmmAccess2.h>\r
+\r
#include <Library/SmmServicesTableLib.h>\r
\r
+#include <Guid/VariableFormat.h>\r
+#include <Guid/SmmVariableCommon.h>\r
#include "Variable.h"\r
-#include "VariableSmmCommon.h"\r
\r
-extern SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY *gVariableInfo;\r
+EFI_SMRAM_DESCRIPTOR *mSmramRanges;\r
+UINTN mSmramRangeCount;\r
+\r
+extern VARIABLE_INFO_ENTRY *gVariableInfo;\r
EFI_HANDLE mSmmVariableHandle = NULL;\r
EFI_HANDLE mVariableHandle = NULL;\r
BOOLEAN mAtRuntime = FALSE;\r
EFI_GUID mZeroGuid = {0, 0, 0, {0, 0, 0, 0, 0, 0, 0, 0}};\r
-EFI_GUID mSmmVariableWriteGuid = EFI_SMM_VARIABLE_WRITE_GUID;\r
\r
EFI_SMM_VARIABLE_PROTOCOL gSmmVariable = {\r
VariableServiceGetVariable,\r
return mAtRuntime;\r
}\r
\r
+/**\r
+ This function check if the address is in SMRAM.\r
+\r
+ @param Buffer the buffer address to be checked.\r
+ @param Length the buffer length to be checked.\r
+\r
+ @retval TRUE this address is in SMRAM.\r
+ @retval FALSE this address is NOT in SMRAM.\r
+**/\r
+BOOLEAN\r
+InternalIsAddressInSmram (\r
+ IN EFI_PHYSICAL_ADDRESS Buffer,\r
+ IN UINT64 Length\r
+ )\r
+{\r
+ UINTN Index;\r
+\r
+ for (Index = 0; Index < mSmramRangeCount; Index ++) {\r
+ if (((Buffer >= mSmramRanges[Index].CpuStart) && (Buffer < mSmramRanges[Index].CpuStart + mSmramRanges[Index].PhysicalSize)) ||\r
+ ((mSmramRanges[Index].CpuStart >= Buffer) && (mSmramRanges[Index].CpuStart < Buffer + Length))) {\r
+ return TRUE;\r
+ }\r
+ }\r
+\r
+ return FALSE;\r
+}\r
+\r
+/**\r
+ This function check if the address refered by Buffer and Length is valid.\r
+\r
+ @param Buffer the buffer address to be checked.\r
+ @param Length the buffer length to be checked.\r
+\r
+ @retval TRUE this address is valid.\r
+ @retval FALSE this address is NOT valid.\r
+**/\r
+BOOLEAN\r
+InternalIsAddressValid (\r
+ IN UINTN Buffer,\r
+ IN UINTN Length\r
+ )\r
+{\r
+ if (Buffer > (MAX_ADDRESS - Length)) {\r
+ //\r
+ // Overflow happen\r
+ //\r
+ return FALSE;\r
+ }\r
+ if (InternalIsAddressInSmram ((EFI_PHYSICAL_ADDRESS)Buffer, (UINT64)Length)) {\r
+ return FALSE;\r
+ }\r
+ return TRUE;\r
+}\r
+\r
/**\r
Initializes a basic mutual exclusion lock.\r
\r
/**\r
Get the variable statistics information from the information buffer pointed by gVariableInfo.\r
\r
- @param[in, out] InfoEntry A pointer to the buffer of variable information entry.\r
- On input, point to the variable information returned last time. if \r
- InfoEntry->VendorGuid is zero, return the first information.\r
- On output, point to the next variable information.\r
- @param[in, out] InfoSize On input, the size of the variable information buffer.\r
- On output, the returned variable information size.\r
+ Caution: This function may be invoked at SMM runtime.\r
+ InfoEntry and InfoSize are external input. Care must be taken to make sure not security issue at runtime.\r
+\r
+ @param[in, out] InfoEntry A pointer to the buffer of variable information entry.\r
+ On input, point to the variable information returned last time. if \r
+ InfoEntry->VendorGuid is zero, return the first information.\r
+ On output, point to the next variable information.\r
+ @param[in, out] InfoSize On input, the size of the variable information buffer.\r
+ On output, the returned variable information size.\r
\r
@retval EFI_SUCCESS The variable information is found and returned successfully.\r
@retval EFI_UNSUPPORTED No variable inoformation exists in variable driver. The \r
**/\r
EFI_STATUS\r
SmmVariableGetStatistics (\r
- IN OUT SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY *InfoEntry,\r
+ IN OUT VARIABLE_INFO_ENTRY *InfoEntry,\r
IN OUT UINTN *InfoSize\r
)\r
{\r
- SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY *VariableInfo;\r
+ VARIABLE_INFO_ENTRY *VariableInfo;\r
UINTN NameLength;\r
UINTN StatisticsInfoSize;\r
CHAR16 *InfoName;\r
return EFI_UNSUPPORTED;\r
}\r
\r
- StatisticsInfoSize = sizeof (SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY) + StrSize (VariableInfo->Name);\r
- if (*InfoSize < sizeof (SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY)) {\r
+ StatisticsInfoSize = sizeof (VARIABLE_INFO_ENTRY) + StrSize (VariableInfo->Name);\r
+ if (*InfoSize < StatisticsInfoSize) {\r
*InfoSize = StatisticsInfoSize;\r
return EFI_BUFFER_TOO_SMALL;\r
}\r
//\r
// Return the first variable info\r
//\r
- CopyMem (InfoEntry, VariableInfo, sizeof (SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY));\r
+ CopyMem (InfoEntry, VariableInfo, sizeof (VARIABLE_INFO_ENTRY));\r
CopyMem (InfoName, VariableInfo->Name, StrSize (VariableInfo->Name));\r
*InfoSize = StatisticsInfoSize;\r
return EFI_SUCCESS;\r
//\r
// Output the new variable info\r
//\r
- StatisticsInfoSize = sizeof (SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY) + StrSize (VariableInfo->Name);\r
+ StatisticsInfoSize = sizeof (VARIABLE_INFO_ENTRY) + StrSize (VariableInfo->Name);\r
if (*InfoSize < StatisticsInfoSize) {\r
*InfoSize = StatisticsInfoSize;\r
return EFI_BUFFER_TOO_SMALL;\r
}\r
\r
- CopyMem (InfoEntry, VariableInfo, sizeof (SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY));\r
+ CopyMem (InfoEntry, VariableInfo, sizeof (VARIABLE_INFO_ENTRY));\r
CopyMem (InfoName, VariableInfo->Name, StrSize (VariableInfo->Name));\r
*InfoSize = StatisticsInfoSize;\r
\r
\r
This SMI handler provides services for the variable wrapper driver.\r
\r
+ Caution: This function may receive untrusted input.\r
+ This variable data and communicate buffer are external input, so this function will do basic validation.\r
+ Each sub function VariableServiceGetVariable(), VariableServiceGetNextVariableName(), \r
+ VariableServiceSetVariable(), VariableServiceQueryVariableInfo(), ReclaimForOS(), \r
+ SmmVariableGetStatistics() should also do validation based on its own knowledge.\r
+\r
@param[in] DispatchHandle The unique handle assigned to this handler by SmiHandlerRegister().\r
@param[in] RegisterContext Points to an optional handler context which was specified when the\r
handler was registered.\r
SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE *SmmVariableHeader;\r
SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME *GetNextVariableName;\r
SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO *QueryVariableInfo;\r
- SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY *VariableInfo;\r
+ VARIABLE_INFO_ENTRY *VariableInfo;\r
UINTN InfoSize;\r
+ UINTN NameBufferSize;\r
+\r
+ //\r
+ // If input is invalid, stop processing this SMI\r
+ //\r
+ if (CommBuffer == NULL || CommBufferSize == NULL) {\r
+ return EFI_SUCCESS;\r
+ }\r
\r
- ASSERT (CommBuffer != NULL);\r
+ if (*CommBufferSize < SMM_VARIABLE_COMMUNICATE_HEADER_SIZE) {\r
+ return EFI_SUCCESS;\r
+ }\r
+\r
+ if (!InternalIsAddressValid ((UINTN)CommBuffer, *CommBufferSize)) {\r
+ DEBUG ((EFI_D_ERROR, "SMM communication buffer in SMRAM or overflow!\n"));\r
+ return EFI_SUCCESS;\r
+ }\r
\r
SmmVariableFunctionHeader = (SMM_VARIABLE_COMMUNICATE_HEADER *)CommBuffer;\r
switch (SmmVariableFunctionHeader->Function) {\r
case SMM_VARIABLE_FUNCTION_GET_VARIABLE:\r
- SmmVariableHeader = (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE *) SmmVariableFunctionHeader->Data; \r
+ SmmVariableHeader = (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE *) SmmVariableFunctionHeader->Data;\r
+ if (((UINTN)(~0) - SmmVariableHeader->DataSize < OFFSET_OF(SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name)) ||\r
+ ((UINTN)(~0) - SmmVariableHeader->NameSize < OFFSET_OF(SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name) + SmmVariableHeader->DataSize)) {\r
+ //\r
+ // Prevent InfoSize overflow happen\r
+ //\r
+ Status = EFI_ACCESS_DENIED;\r
+ goto EXIT;\r
+ }\r
+ InfoSize = OFFSET_OF(SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name) \r
+ + SmmVariableHeader->DataSize + SmmVariableHeader->NameSize;\r
+\r
+ //\r
+ // SMRAM range check already covered before\r
+ //\r
+ if (InfoSize > *CommBufferSize - SMM_VARIABLE_COMMUNICATE_HEADER_SIZE) {\r
+ DEBUG ((EFI_D_ERROR, "Data size exceed communication buffer size limit!\n"));\r
+ Status = EFI_ACCESS_DENIED;\r
+ goto EXIT;\r
+ }\r
+\r
+ if (SmmVariableHeader->NameSize < sizeof (CHAR16) || SmmVariableHeader->Name[SmmVariableHeader->NameSize/sizeof (CHAR16) - 1] != L'\0') {\r
+ //\r
+ // Make sure VariableName is A Null-terminated string.\r
+ //\r
+ Status = EFI_ACCESS_DENIED;\r
+ goto EXIT;\r
+ }\r
+\r
Status = VariableServiceGetVariable (\r
SmmVariableHeader->Name,\r
&SmmVariableHeader->Guid,\r
\r
case SMM_VARIABLE_FUNCTION_GET_NEXT_VARIABLE_NAME:\r
GetNextVariableName = (SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME *) SmmVariableFunctionHeader->Data;\r
+ if ((UINTN)(~0) - GetNextVariableName->NameSize < OFFSET_OF(SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME, Name)) {\r
+ //\r
+ // Prevent InfoSize overflow happen\r
+ //\r
+ Status = EFI_ACCESS_DENIED;\r
+ goto EXIT;\r
+ }\r
+ InfoSize = OFFSET_OF(SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME, Name) + GetNextVariableName->NameSize;\r
+\r
+ //\r
+ // SMRAM range check already covered before\r
+ //\r
+ if (InfoSize > *CommBufferSize - SMM_VARIABLE_COMMUNICATE_HEADER_SIZE) {\r
+ DEBUG ((EFI_D_ERROR, "Data size exceed communication buffer size limit!\n"));\r
+ Status = EFI_ACCESS_DENIED;\r
+ goto EXIT;\r
+ }\r
+\r
+ NameBufferSize = *CommBufferSize - SMM_VARIABLE_COMMUNICATE_HEADER_SIZE - OFFSET_OF(SMM_VARIABLE_COMMUNICATE_GET_NEXT_VARIABLE_NAME, Name);\r
+ if (NameBufferSize < sizeof (CHAR16) || GetNextVariableName->Name[NameBufferSize/sizeof (CHAR16) - 1] != L'\0') {\r
+ //\r
+ // Make sure input VariableName is A Null-terminated string.\r
+ //\r
+ Status = EFI_ACCESS_DENIED;\r
+ goto EXIT;\r
+ }\r
+\r
Status = VariableServiceGetNextVariableName (\r
&GetNextVariableName->NameSize,\r
GetNextVariableName->Name,\r
\r
case SMM_VARIABLE_FUNCTION_SET_VARIABLE:\r
SmmVariableHeader = (SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE *) SmmVariableFunctionHeader->Data;\r
+ if (((UINTN)(~0) - SmmVariableHeader->DataSize < OFFSET_OF(SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name)) ||\r
+ ((UINTN)(~0) - SmmVariableHeader->NameSize < OFFSET_OF(SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name) + SmmVariableHeader->DataSize)) {\r
+ //\r
+ // Prevent InfoSize overflow happen\r
+ //\r
+ Status = EFI_ACCESS_DENIED;\r
+ goto EXIT;\r
+ }\r
+ InfoSize = OFFSET_OF(SMM_VARIABLE_COMMUNICATE_ACCESS_VARIABLE, Name)\r
+ + SmmVariableHeader->DataSize + SmmVariableHeader->NameSize;\r
+\r
+ //\r
+ // SMRAM range check already covered before\r
+ // Data buffer should not contain SMM range\r
+ //\r
+ if (InfoSize > *CommBufferSize - SMM_VARIABLE_COMMUNICATE_HEADER_SIZE) {\r
+ DEBUG ((EFI_D_ERROR, "Data size exceed communication buffer size limit!\n"));\r
+ Status = EFI_ACCESS_DENIED;\r
+ goto EXIT;\r
+ }\r
+\r
+ if (SmmVariableHeader->NameSize < sizeof (CHAR16) || SmmVariableHeader->Name[SmmVariableHeader->NameSize/sizeof (CHAR16) - 1] != L'\0') {\r
+ //\r
+ // Make sure VariableName is A Null-terminated string.\r
+ //\r
+ Status = EFI_ACCESS_DENIED;\r
+ goto EXIT;\r
+ }\r
+\r
Status = VariableServiceSetVariable (\r
SmmVariableHeader->Name,\r
&SmmVariableHeader->Guid,\r
\r
case SMM_VARIABLE_FUNCTION_QUERY_VARIABLE_INFO:\r
QueryVariableInfo = (SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO *) SmmVariableFunctionHeader->Data;\r
+ InfoSize = sizeof(SMM_VARIABLE_COMMUNICATE_QUERY_VARIABLE_INFO);\r
+\r
+ //\r
+ // SMRAM range check already covered before\r
+ //\r
+ if (InfoSize > *CommBufferSize - SMM_VARIABLE_COMMUNICATE_HEADER_SIZE) {\r
+ DEBUG ((EFI_D_ERROR, "Data size exceed communication buffer size limit!\n"));\r
+ Status = EFI_ACCESS_DENIED;\r
+ goto EXIT;\r
+ }\r
+\r
Status = VariableServiceQueryVariableInfo (\r
QueryVariableInfo->Attributes,\r
&QueryVariableInfo->MaximumVariableStorageSize,\r
break;\r
\r
case SMM_VARIABLE_FUNCTION_READY_TO_BOOT:\r
+ if (AtRuntime()) {\r
+ Status = EFI_UNSUPPORTED;\r
+ break;\r
+ }\r
ReclaimForOS ();\r
Status = EFI_SUCCESS;\r
break;\r
break;\r
\r
case SMM_VARIABLE_FUNCTION_GET_STATISTICS:\r
- VariableInfo = (SMM_VARIABLE_COMMUNICATE_VARIABLE_INFO_ENTRY *) SmmVariableFunctionHeader->Data;\r
- InfoSize = *CommBufferSize - OFFSET_OF (SMM_VARIABLE_COMMUNICATE_HEADER, Data);\r
+ VariableInfo = (VARIABLE_INFO_ENTRY *) SmmVariableFunctionHeader->Data;\r
+ InfoSize = *CommBufferSize - SMM_VARIABLE_COMMUNICATE_HEADER_SIZE;\r
+\r
+ //\r
+ // Do not need to check SmmVariableFunctionHeader->Data in SMRAM here. \r
+ // It is covered by previous CommBuffer check \r
+ //\r
+ \r
+ if (InternalIsAddressInSmram ((EFI_PHYSICAL_ADDRESS)(UINTN)CommBufferSize, sizeof(UINTN))) {\r
+ DEBUG ((EFI_D_ERROR, "SMM communication buffer in SMRAM!\n"));\r
+ Status = EFI_ACCESS_DENIED;\r
+ goto EXIT;\r
+ } \r
+\r
Status = SmmVariableGetStatistics (VariableInfo, &InfoSize);\r
- *CommBufferSize = InfoSize + OFFSET_OF (SMM_VARIABLE_COMMUNICATE_HEADER, Data);\r
+ *CommBufferSize = InfoSize + SMM_VARIABLE_COMMUNICATE_HEADER_SIZE;\r
break;\r
\r
default:\r
- ASSERT (FALSE);\r
Status = EFI_UNSUPPORTED;\r
}\r
\r
+EXIT:\r
+\r
SmmVariableFunctionHeader->ReturnStatus = Status;\r
\r
return EFI_SUCCESS;\r
//\r
// Ensure SMM FTW protocol is installed.\r
//\r
- Status = GetFtwProtocol (&FtwProtocol);\r
+ Status = GetFtwProtocol ((VOID **)&FtwProtocol);\r
if (EFI_ERROR (Status)) {\r
return Status;\r
}\r
//\r
Status = gBS->InstallProtocolInterface (\r
&mSmmVariableHandle,\r
- &mSmmVariableWriteGuid,\r
+ &gSmmVariableWriteGuid,\r
EFI_NATIVE_INTERFACE,\r
NULL\r
);\r
/**\r
Variable Driver main entry point. The Variable driver places the 4 EFI\r
runtime services in the EFI System Table and installs arch protocols \r
- for variable read and write services being availible. It also registers\r
+ for variable read and write services being available. It also registers\r
a notification function for an EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE event.\r
\r
@param[in] ImageHandle The firmware allocated handle for the EFI image. \r
EFI_STATUS Status;\r
EFI_HANDLE VariableHandle;\r
VOID *SmmFtwRegistration;\r
- \r
+ EFI_SMM_ACCESS2_PROTOCOL *SmmAccess;\r
+ UINTN Size;\r
+\r
//\r
// Variable initialize.\r
//\r
);\r
ASSERT_EFI_ERROR (Status);\r
\r
+ //\r
+ // Get SMRAM information\r
+ //\r
+ Status = gBS->LocateProtocol (&gEfiSmmAccess2ProtocolGuid, NULL, (VOID **)&SmmAccess);\r
+ ASSERT_EFI_ERROR (Status);\r
+\r
+ Size = 0;\r
+ Status = SmmAccess->GetCapabilities (SmmAccess, &Size, NULL);\r
+ ASSERT (Status == EFI_BUFFER_TOO_SMALL);\r
+\r
+ Status = gSmst->SmmAllocatePool (\r
+ EfiRuntimeServicesData,\r
+ Size,\r
+ (VOID **)&mSmramRanges\r
+ );\r
+ ASSERT_EFI_ERROR (Status);\r
+\r
+ Status = SmmAccess->GetCapabilities (SmmAccess, &Size, mSmramRanges);\r
+ ASSERT_EFI_ERROR (Status);\r
+\r
+ mSmramRangeCount = Size / sizeof (EFI_SMRAM_DESCRIPTOR);\r
+\r
///\r
/// Register SMM variable SMI handler\r
///\r
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