Gulu la ofufuza ochokera ku mayunivesite aku America, Australia ndi Israeli apereka njira yatsopano yowukira njira kuti agwiritse ntchito ziwopsezo za Specter-class mu asakatuli potengera injini ya Chromium. Kuwukirako, kotchedwa Spook.js, kumakupatsani mwayi wodutsa njira yodzipatula pamasamba pogwiritsa ntchito JavaScript code ndikuwerenga zomwe zili mu adilesi yonse yazomwe zikuchitika, i.e. pezani zambiri kuchokera pamasamba omwe ali m'ma tabo ena, koma amakonzedwa mwanjira yomweyo.
Popeza Chrome imayendetsa masamba osiyanasiyana m'njira zosiyanasiyana, kuthekera kochita ziwopsezo kumangokhala ndi mautumiki omwe amalola ogwiritsa ntchito osiyanasiyana kukhala ndi masamba awo. Njirayi imalola, kuchokera patsamba lomwe wowukirayo ali ndi mwayi woyika JavaScript code yake, kudziwa kupezeka kwa masamba ena otsegulidwa ndi wogwiritsa ntchito patsamba lomwelo ndikuchotsa zinsinsi kuchokera kwa iwo, mwachitsanzo, zidziwitso kapena zidziwitso za banki zomwe zasinthidwa. ndi dongosolo la magawo odzaza okha mu mafomu a intaneti. Monga chiwonetsero, zikuwonetsedwa momwe mungawukire blog ya munthu wina pa ntchito ya Tumblr ngati mwiniwake atsegula blog ya owukira omwe amachitika pautumiki womwewo mu tabu ina.
Njira ina yogwiritsira ntchito njirayi ndikuwukira pazowonjezera za osatsegula, zomwe zimalola, pakuyika zowonjezera zomwe zimayendetsedwa ndi wowukirayo, kuchotsa deta kuchokera pazowonjezera zina. Mwachitsanzo, tikuwonetsani momwe mungayikitsire chowonjezera choyipa chomwe mungachotsere zinsinsi kuchokera kwa manejala achinsinsi a LastPass.
Ofufuza adasindikiza chiwonetsero chazomwe zimagwira ntchito mu Chrome 89 pamakina okhala ndi CPUIntel i7-6700K ndi i7-7600U. Popanga izi, ma prototypes a JavaScript code omwe adasindikizidwa kale ndi Google adagwiritsidwa ntchito kuchita ziwonetsero za Specter-class. Zikudziwika kuti ochita kafukufuku adatha kukonzekera ntchito zogwirira ntchito za machitidwe opangidwa ndi Intel ndi Apple M1 processors, zomwe zimapangitsa kuti zitheke kukonzekera kuwerenga kukumbukira pa liwiro la 500 bytes pamphindi ndi kulondola kwa 96%. Zimaganiziridwa kuti njirayi ikugwiritsidwanso ntchito kwa mapurosesa a AMD, koma sikunali kotheka kukonzekera kugwiritsira ntchito mokwanira.
Kuwukiraku kumagwira ntchito pa asakatuli aliwonse otengera injini ya Chromium, kuphatikiza Google Chrome, Microsoft Edge ndi Brave. Ofufuzawo amakhulupiriranso kuti njirayo ingasinthidwe kuti igwire ntchito ndi Firefox, koma popeza injini ya Firefox ndi yosiyana kwambiri ndi Chrome, ntchito yolenga kugwiritsira ntchito koteroko yatsala mtsogolo.
Kuti muteteze motsutsana ndi osatsegula okhudzana ndi kutsata malangizo mongopeka, Chrome imagwiritsa ntchito magawo a ma adilesi - kudzipatula kwa sandbox kumalola JavaScript kuti igwire ntchito ndi zolozera za 32-bit ndikugawana kukumbukira kwa othandizira mu milu ya 4GB yosagwirizana. Kuti apereke mwayi wofikira malo onse a adilesi ndikudutsa malire a 32-bit, ofufuzawo adagwiritsa ntchito njira yotchedwa Type Confusion, yomwe imakakamiza injini ya JavaScript kuti ipange chinthu ndi mtundu wolakwika, zomwe zimapangitsa kuti pakhale 64-bit. pointer yotengera kuphatikiza kwazinthu ziwiri za 32-bit.
Chofunikira pakuwukirako ndikuti mukakonza chinthu choyipa chomwe chidapangidwa mwapadera mu injini ya JavaScript, zinthu zimapangidwa zomwe zimatsogolera pakungopeka kwa malangizo omwe amafikira mndandandawo. Chinthucho chimasankhidwa m'njira yoti minda yoyendetsedwa ndi owukirayo imayikidwa pamalo omwe 64-bit pointer imagwiritsidwa ntchito. Popeza mtundu wa chinthu choyipa sichikugwirizana ndi mtundu wa gulu lomwe likukonzedwa, nthawi zonse zinthu zoterezi zimatsekedwa mu Chrome ndi njira yochepetsera ma code omwe amagwiritsidwa ntchito kuti apeze magulu. Kuti athetse vutoli, code ya mtundu wa Chisokonezo cha kuukira imayikidwa mu chipika chokhazikika "ngati", chomwe sichimayendetsedwa pansi pazikhalidwe zabwino, koma chimachitidwa mongoganizira, ngati purosesa ikulosera molakwika nthambi zina.
Zotsatira zake, purosesa mongoyerekeza amapeza cholozera chopangidwa ndi 64-bit ndikubweza boma atazindikira zomwe zalephera, koma zotsatira zake zimakhalabe m'malo omwe adagawana nawo ndipo zitha kubwezeretsedwanso pogwiritsa ntchito njira zodziwira cache zam'mbali zomwe zimasanthula zosintha mu. nthawi zofikira ku data yosungidwa komanso yosasungidwa. Kusanthula zomwe zili mu cache muzochitika zosakwanira kulondola kwa nthawi yomwe ikupezeka mu JavaScript, njira yoperekedwa ndi Google imagwiritsidwa ntchito, yomwe imanyenga njira yothamangitsira cache ya Tree-PLRU yomwe imagwiritsidwa ntchito m'mapulosesa ndikulola, poonjezera chiwerengero cha maulendo, onjezerani kwambiri kusiyana kwa nthawi yomwe mtengo ulipo komanso kulibe mu cache.
Source: opennet.ru