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Reject malformed savestate container metadata #2712

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Reject malformed savestate container metadata #2712

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18 changes: 18 additions & 0 deletions src/FIFO.h
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Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,12 @@ class FIFO
file->Var32(&WritePos);

file->VarArray(Entries, sizeof(T)*NumEntries);

if (!file->Saving && !file->Error &&
(NumOccupied > NumEntries || ReadPos >= NumEntries || WritePos >= NumEntries))
{
file->Error = true;
}
}


Expand Down Expand Up @@ -136,6 +142,12 @@ class DynamicFIFO
file->Var32(&WritePos);

file->VarArray(Entries, sizeof(T)*NumEntries);

if (!file->Saving && !file->Error &&
(NumOccupied > NumEntries || ReadPos >= NumEntries || WritePos >= NumEntries))
{
file->Error = true;
}
}


Expand Down Expand Up @@ -213,6 +225,12 @@ class RingBuffer
file->Var32(&WritePos);

file->VarArray(Buffer, Size);

if (!file->Saving && !file->Error &&
(NumOccupied > Size || ReadPos >= Size || WritePos >= Size))
{
file->Error = true;
}
}


Expand Down
22 changes: 14 additions & 8 deletions src/Savestate.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -367,6 +367,12 @@ u32 Savestate::FindSection(const char* magic) const
for (u32 offset = 0x10; offset < buffer_length;)
{ // Until we've found the desired section...

if (buffer_length - offset < 16)
{
Log(LogLevel::Error, "savestate: truncated section header\n");
return NO_SECTION;
}

// Get this section's magic number
char read_magic[4] = {0};
memcpy(read_magic, buffer + offset, sizeof(read_magic));
Expand All @@ -378,15 +384,15 @@ u32 Savestate::FindSection(const char* magic) const

// Haven't found our section yet. Let's move on to the next one.

u32 section_length_offset = offset + sizeof(read_magic);
if (section_length_offset >= buffer_length)
{ // If trying to read the section length would take us past the file's end...
break;
}

// First we need to find out how big this section is...
u32 section_length = 0;
memcpy(&section_length, buffer + section_length_offset, sizeof(section_length));
memcpy(&section_length, buffer + offset + sizeof(read_magic), sizeof(section_length));

if (section_length < 16 || section_length > buffer_length - offset)
{
Log(LogLevel::Error, "savestate: invalid section length %u\n", section_length);
return NO_SECTION;
}

// ...then skip it. (The section length includes the 16-byte header.)
offset += section_length;
Expand All @@ -397,4 +403,4 @@ u32 Savestate::FindSection(const char* magic) const
return NO_SECTION;
}

}
}