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Stack pointer validation for call function/method opcodes #237

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merged 2 commits into from
Nov 27, 2024
Merged

Stack pointer validation for call function/method opcodes #237

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66600dc
Added stack pointer validation for call function/method opcodes.
MiranDMC Nov 24, 2024
c9fa064
More detailed error message.
MiranDMC Nov 27, 2024
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19 changes: 19 additions & 0 deletions cleo_plugins/MemoryOperations/MemoryOperations.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -161,8 +161,11 @@ class MemoryOperations
SCRIPT_VAR* arguments_end = arguments + numArg;
numPop *= 4; // bytes peer argument
DWORD result;
int oriSp, postSp; // stack validation
_asm
{
mov oriSp, esp

// transfer args to stack
lea ecx, arguments
call_func_loop :
Expand All @@ -179,6 +182,22 @@ class MemoryOperations
call func
mov result, eax // get result
add esp, numPop // cleanup stack

mov postSp, esp
}

// validate stack pointer
if (postSp != oriSp)
{
_asm
{
mov esp, oriSp // fix stack pointer
}

int diff = oriSp - postSp;
int requiredPop = (numPop + diff) / 4;
SHOW_ERROR("Function call left stack position changed (%s%d). This usually happens when incorrect calling convention is used. \nArgument 'pop' value should have been %d in script %s \nScript suspended.", diff > 0 ? "+" : "", diff, requiredPop, CLEO::ScriptInfoStr(thread).c_str());
return thread->Suspend();
}

if (returnArg)
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