From 62cefaf44e1cc14376e547e955a846ba456caa93 Mon Sep 17 00:00:00 2001 From: Krzysztof Koch Date: Thu, 1 Aug 2019 16:44:04 -0700 Subject: [PATCH] ShellPkg: acpiview: IORT: Prevent buffer overruns Modify the IORT table parsing logic to prevent reading past the buffer lengths provided. Change DumpIortNodeIdMappings() function's signature and implementation to simplify buffer overrun prevention. Update all calls to this function accordingly. Modify the parser for each type of IORT node such that the offset from the start of the node's buffer is tracked as the parsing function is executed. Again, this change helps prevent buffer overruns. Test that the IORT node buffer fits in the table buffer before the node's buffer contents are dumped. References: - IO Remapping Table (Issue D), Platform Design Document, March 2018 Signed-off-by: Krzysztof Koch Reviewed-by: Alexei Fedorov Reviewed-by: Zhichao Gao Reviewed-by: Sami Mujawar --- .../Parsers/Iort/IortParser.c | 191 ++++++++++-------- 1 file changed, 105 insertions(+), 86 deletions(-) diff --git a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Iort/IortParser.c b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Iort/IortParser.c index 7c850b3813..8912d415a7 100644 --- a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Iort/IortParser.c +++ b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Iort/IortParser.c @@ -247,42 +247,41 @@ STATIC CONST ACPI_PARSER IortNodePmcgParser[] = { /** This function parses the IORT Node Id Mapping array. - @param [in] Ptr Pointer to the start of the IORT Table. + @param [in] Ptr Pointer to the start of the ID mapping array. + @param [in] Length Length of the buffer. @param [in] MappingCount The ID Mapping count. - @param [in] MappingOffset The offset of the ID Mapping array - from the start of the IORT table. **/ STATIC VOID DumpIortNodeIdMappings ( IN UINT8* Ptr, - IN UINT32 MappingCount, - IN UINT32 MappingOffset + IN UINT32 Length, + IN UINT32 MappingCount ) { - UINT8* IdMappingPtr; UINT32 Index; UINT32 Offset; CHAR8 Buffer[40]; // Used for AsciiName param of ParseAcpi - IdMappingPtr = Ptr + MappingOffset; Index = 0; - while (Index < MappingCount) { + Offset = 0; + + while ((Index < MappingCount) && + (Offset < Length)) { AsciiSPrint ( Buffer, sizeof (Buffer), "ID Mapping [%d]", Index ); - Offset = ParseAcpi ( - TRUE, - 4, - Buffer, - IdMappingPtr, - 20, - PARSER_PARAMS (IortNodeIdMappingParser) - ); - IdMappingPtr += Offset; + Offset += ParseAcpi ( + TRUE, + 4, + Buffer, + Ptr + Offset, + Length - Offset, + PARSER_PARAMS (IortNodeIdMappingParser) + ); Index++; } } @@ -309,8 +308,6 @@ DumpIortNodeSmmuV1V2 ( UINT32 Offset; CHAR8 Buffer[50]; // Used for AsciiName param of ParseAcpi - UINT8* ArrayPtr; - ParseAcpi ( TRUE, 2, @@ -320,51 +317,55 @@ DumpIortNodeSmmuV1V2 ( PARSER_PARAMS (IortNodeSmmuV1V2Parser) ); - ArrayPtr = Ptr + *InterruptContextOffset; + Offset = *InterruptContextOffset; Index = 0; - while (Index < *InterruptContextCount) { + + while ((Index < *InterruptContextCount) && + (Offset < Length)) { AsciiSPrint ( Buffer, sizeof (Buffer), "Context Interrupts Array [%d]", Index ); - Offset = ParseAcpi ( - TRUE, - 4, - Buffer, - ArrayPtr, - 8, - PARSER_PARAMS (InterruptArrayParser) - ); - ArrayPtr += Offset; + Offset += ParseAcpi ( + TRUE, + 4, + Buffer, + Ptr + Offset, + Length - Offset, + PARSER_PARAMS (InterruptArrayParser) + ); Index++; } - ArrayPtr = Ptr + *PmuInterruptOffset; + Offset = *PmuInterruptOffset; Index = 0; - while (Index < *PmuInterruptCount) { + + while ((Index < *PmuInterruptCount) && + (Offset < Length)) { AsciiSPrint ( Buffer, sizeof (Buffer), "PMU Interrupts Array [%d]", Index ); - Offset = ParseAcpi ( - TRUE, - 4, - Buffer, - ArrayPtr, - 8, - PARSER_PARAMS (InterruptArrayParser) - ); - ArrayPtr += Offset; + Offset += ParseAcpi ( + TRUE, + 4, + Buffer, + Ptr + Offset, + Length - Offset, + PARSER_PARAMS (InterruptArrayParser) + ); Index++; } - if (*IortIdMappingCount != 0) { - DumpIortNodeIdMappings (Ptr, MappingCount, MappingOffset); - } + DumpIortNodeIdMappings ( + Ptr + MappingOffset, + Length - MappingOffset, + MappingCount + ); } /** @@ -394,9 +395,11 @@ DumpIortNodeSmmuV3 ( PARSER_PARAMS (IortNodeSmmuV3Parser) ); - if (*IortIdMappingCount != 0) { - DumpIortNodeIdMappings (Ptr, MappingCount, MappingOffset); - } + DumpIortNodeIdMappings ( + Ptr + MappingOffset, + Length - MappingOffset, + MappingCount + ); } /** @@ -414,40 +417,40 @@ DumpIortNodeIts ( { UINT32 Offset; UINT32 Index; - UINT8* ItsIdPtr; CHAR8 Buffer[80]; // Used for AsciiName param of ParseAcpi Offset = ParseAcpi ( - TRUE, - 2, - "ITS Node", - Ptr, - Length, - PARSER_PARAMS (IortNodeItsParser) - ); + TRUE, + 2, + "ITS Node", + Ptr, + Length, + PARSER_PARAMS (IortNodeItsParser) + ); - ItsIdPtr = Ptr + Offset; Index = 0; - while (Index < *ItsCount) { + + while ((Index < *ItsCount) && + (Offset < Length)) { AsciiSPrint ( Buffer, sizeof (Buffer), "GIC ITS Identifier Array [%d]", Index ); - Offset = ParseAcpi ( - TRUE, - 4, - Buffer, - ItsIdPtr, - 4, - PARSER_PARAMS (ItsIdParser) - ); - ItsIdPtr += Offset; + Offset += ParseAcpi ( + TRUE, + 4, + Buffer, + Ptr + Offset, + Length - Offset, + PARSER_PARAMS (ItsIdParser) + ); Index++; } // Note: ITS does not have the ID Mappings Array + } /** @@ -470,8 +473,6 @@ DumpIortNodeNamedComponent ( { UINT32 Offset; UINT32 Index; - UINT8* DeviceNamePtr; - UINT32 DeviceNameLength; Offset = ParseAcpi ( TRUE, @@ -482,19 +483,22 @@ DumpIortNodeNamedComponent ( PARSER_PARAMS (IortNodeNamedComponentParser) ); - DeviceNamePtr = Ptr + Offset; // Estimate the Device Name length - DeviceNameLength = Length - Offset - (MappingCount * 20); PrintFieldName (2, L"Device Object Name"); Index = 0; - while ((Index < DeviceNameLength) && (DeviceNamePtr[Index] != 0)) { - Print (L"%c", DeviceNamePtr[Index++]); + + while ((*(Ptr + Offset) != 0) && + (Offset < Length)) { + Print (L"%c", *(Ptr + Offset)); + Offset++; } Print (L"\n"); - if (*IortIdMappingCount != 0) { - DumpIortNodeIdMappings (Ptr, MappingCount, MappingOffset); - } + DumpIortNodeIdMappings ( + Ptr + MappingOffset, + Length - MappingOffset, + MappingCount + ); } /** @@ -524,9 +528,11 @@ DumpIortNodeRootComplex ( PARSER_PARAMS (IortNodeRootComplexParser) ); - if (*IortIdMappingCount != 0) { - DumpIortNodeIdMappings (Ptr, MappingCount, MappingOffset); - } + DumpIortNodeIdMappings ( + Ptr + MappingOffset, + Length - MappingOffset, + MappingCount + ); } /** @@ -554,11 +560,13 @@ DumpIortNodePmcg ( Ptr, Length, PARSER_PARAMS (IortNodePmcgParser) - ); + ); - if (*IortIdMappingCount != 0) { - DumpIortNodeIdMappings (Ptr, MappingCount, MappingOffset); - } + DumpIortNodeIdMappings ( + Ptr + MappingOffset, + Length - MappingOffset, + MappingCount + ); } /** @@ -605,23 +613,34 @@ ParseAcpiIort ( AcpiTableLength, PARSER_PARAMS (IortParser) ); + Offset = *IortNodeOffset; NodePtr = Ptr + Offset; Index = 0; - while ((Index < *IortNodeCount) && (Offset < AcpiTableLength)) { + // Parse the specified number of IORT nodes or the IORT table buffer length. + // Whichever is minimum. + while ((Index++ < *IortNodeCount) && + (Offset < AcpiTableLength)) { // Parse the IORT Node Header ParseAcpi ( FALSE, 0, "IORT Node Header", NodePtr, - 16, + AcpiTableLength - Offset, PARSER_PARAMS (IortNodeHeaderParser) ); - if (*IortNodeLength == 0) { + + // Make sure the IORT Node is inside the table + if ((Offset + (*IortNodeLength)) > AcpiTableLength) { IncrementErrorCount (); - Print (L"ERROR: Parser error. Invalid table data.\n"); + Print ( + L"ERROR: Invalid IORT node length. IortNodeLength = %d. " \ + L"RemainingTableBufferLength = %d. IORT parsing aborted.\n", + *IortNodeLength, + AcpiTableLength - Offset + ); return; } -- 2.39.2