empathicqubit/Mesen-X
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Fixed infinite loop when trying to load invalid rom files (when file size does not match header)

Browse source
This commit is contained in:
Sour 2019-01-20 15:04:23 -05:00
parent 1ef80d8cec
commit 2ef8e235c6
3 changed files with 13 additions and 33 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

27
Core/NESHeader.cpp
View file

@ -248,30 +248,3 @@ PpuModel NESHeader::GetVsSystemPpuModel()
} }
return PpuModel::Ppu2C03; return PpuModel::Ppu2C03;
} }
void NESHeader::SanitizeHeader(size_t romLength)
{
uint32_t originalPrgSize = GetPrgSize();
uint32_t originalChrSize = GetChrSize();
size_t calculatedLength = sizeof(NESHeader) + GetPrgSize();
while(calculatedLength > romLength) {
Byte9 = 0;
PrgCount--;
calculatedLength = sizeof(NESHeader) + GetPrgSize();
}
calculatedLength = sizeof(NESHeader) + GetPrgSize() + GetChrSize();
while(calculatedLength > romLength) {
Byte9 = 0;
ChrCount--;
calculatedLength = sizeof(NESHeader) + GetPrgSize() + GetChrSize();
}
if(originalPrgSize != GetPrgSize()) {
MessageManager::Log("[iNes] Invalid ROM file length - PRG data has been truncated.");
}
if(originalChrSize != GetChrSize()) {
MessageManager::Log("[iNes] Invalid ROM file length - CHR data has been truncated.");
}
}

1
Core/NESHeader.h
View file

@ -48,5 +48,4 @@ struct NESHeader
GameInputType GetInputType(); GameInputType GetInputType();
VsSystemType GetVsSystemType(); VsSystemType GetVsSystemType();
PpuModel GetVsSystemPpuModel(); PpuModel GetVsSystemPpuModel();
void SanitizeHeader(size_t romLength);
}; };

18
Core/iNesLoader.cpp
View file

@ -15,11 +15,9 @@ RomData iNesLoader::LoadRom(vector<uint8_t>& romFile, NESHeader *preloadedHeader
uint32_t dataSize = (uint32_t)romFile.size(); uint32_t dataSize = (uint32_t)romFile.size();
if(preloadedHeader) { if(preloadedHeader) {
header = *preloadedHeader; header = *preloadedHeader;
header.SanitizeHeader(romFile.size() + sizeof(NESHeader));
} else { } else {
memcpy((char*)&header, buffer, sizeof(NESHeader)); memcpy((char*)&header, buffer, sizeof(NESHeader));
buffer += sizeof(NESHeader); buffer += sizeof(NESHeader);
header.SanitizeHeader(romFile.size());
dataSize -= sizeof(NESHeader); dataSize -= sizeof(NESHeader);
} }
@ -46,9 +44,16 @@ RomData iNesLoader::LoadRom(vector<uint8_t>& romFile, NESHeader *preloadedHeader
romData.SaveRamSize = header.GetSaveRamSize(); romData.SaveRamSize = header.GetSaveRamSize();
if(romData.Info.HasTrainer) { if(romData.Info.HasTrainer) {
//512-byte trainer at $7000-$71FF (stored before PRG data) if(dataSize >= 512) {
romData.TrainerData.insert(romData.TrainerData.end(), buffer, buffer + 512); //512-byte trainer at $7000-$71FF (stored before PRG data)
buffer += 512; romData.TrainerData.insert(romData.TrainerData.end(), buffer, buffer + 512);
buffer += 512;
dataSize -= 512;
} else {
romData.Error = true;
MessageManager::Log("[iNes] Invalid file (file length does not match header information) - load operation cancelled.");
return romData;
}
} }
size_t bytesRead = buffer - romFile.data(); size_t bytesRead = buffer - romFile.data();
@ -68,8 +73,11 @@ RomData iNesLoader::LoadRom(vector<uint8_t>& romFile, NESHeader *preloadedHeader
if(prgSize + chrSize > dataSize) { if(prgSize + chrSize > dataSize) {
//Invalid rom file //Invalid rom file
MessageManager::Log("[iNes] Invalid file (file length does not match header information) - load operation cancelled.");
romData.Error = true; romData.Error = true;
return romData; return romData;
} else if(prgSize + chrSize < dataSize) {
MessageManager::Log("[iNes] Warning: File is larger than excepted (based on the file header).");
} }
romData.PrgRom.insert(romData.PrgRom.end(), buffer, buffer + prgSize); romData.PrgRom.insert(romData.PrgRom.end(), buffer, buffer + prgSize);