[lldb-dev] malloc of 1 used as 8

Carlo Kok ck at remobjects.com
Mon Mar 4 10:55:49 PST 2013

In IRInterpreter.cpp, memory class there's this code:

Region Malloc (size_t size, size_t align)
lldb::DataBufferSP data(new lldb_private::DataBufferHeap(size, 0));

m_memory.push_back(AllocationSP(new Allocation(base, size, data)));

AllocationSP alloc = m_memory[index];

alloc->m_origin.GetScalar() = (unsigned long long)data->GetBytes();

This last statement presumes that that there's at least sizeof(unsigned 
long long), but this code also gets triggered for booleans (1 byte), in 
which case size is 1.

This works:

lldb::DataBufferSP data(new lldb_private::DataBufferHeap(size < 8 ? 8 : 
size, 0));

But I'm not sure if it's the right fix.

Visual Studio freaks out when things write outside the bounds that were 

Carlo Kok

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