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Impose stricter upper bound on memory accesses in order to prevent overflow/wrap around.

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This commit is contained in:
Bhargava Shastry 2022-01-03 18:22:42 +01:00
parent b8ee17340b
commit 259a98b82c
1 changed files with 3 additions and 1 deletions
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4
test/tools/yulInterpreter/EVMInstructionInterpreter.cpp
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@ -476,7 +476,9 @@ bool EVMInstructionInterpreter::accessMemory(u256 const& _offset, u256 const& _s
{
u256 newSize = (_offset + _size + 0x1f) & ~u256(0x1f);
m_state.msize = max(m_state.msize, newSize);
return _size <= 0xffff;
// We only record accesses to contiguous memory chunks that are at most 0xffff bytes
// in size and at an offset of at most numeric_limits<size_t>::max() - 0xffff
return _size <= 0xffff && _offset <= u256(numeric_limits<size_t>::max() - 0xffff);
}
else
m_state.msize = u256(-1);