implements an SMI handler to communicate with the DXE runtime driver \r
to provide variable services.\r
\r
-Copyright (c) 2010 - 2011, 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
#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
\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
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
/**\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
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
VARIABLE_INFO_ENTRY *VariableInfo;\r
UINTN InfoSize;\r
\r
- ASSERT (CommBuffer != NULL);\r
+ //\r
+ // If input is invalid, stop processing this SMI\r
+ //\r
+ if (CommBuffer == NULL || CommBufferSize == NULL) {\r
+ return EFI_SUCCESS;\r
+ }\r
+\r
+ if (*CommBufferSize < sizeof(SMM_VARIABLE_COMMUNICATE_HEADER) - 1) {\r
+ return EFI_SUCCESS;\r
+ }\r
+\r
+ if (InternalIsAddressInSmram ((EFI_PHYSICAL_ADDRESS)(UINTN)CommBuffer, *CommBufferSize)) {\r
+ DEBUG ((EFI_D_ERROR, "SMM communication buffer size is in SMRAM!\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
+ 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 - OFFSET_OF (SMM_VARIABLE_COMMUNICATE_HEADER, Data)) {\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 = 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
+ 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 - OFFSET_OF (SMM_VARIABLE_COMMUNICATE_HEADER, Data)) {\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 = VariableServiceGetNextVariableName (\r
&GetNextVariableName->NameSize,\r
GetNextVariableName->Name,\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 - OFFSET_OF (SMM_VARIABLE_COMMUNICATE_HEADER, Data)) {\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
case SMM_VARIABLE_FUNCTION_GET_STATISTICS:\r
VariableInfo = (VARIABLE_INFO_ENTRY *) SmmVariableFunctionHeader->Data;\r
InfoSize = *CommBufferSize - OFFSET_OF (SMM_VARIABLE_COMMUNICATE_HEADER, Data);\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 size is 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
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
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
projects / mirror_edk2.git / commitdiff