Sasha Levin wa ku NVIDIA, yemwe amasamalira nthambi za LTS za kernel ya Linux ndipo ali m'gulu la alangizi a Linux Foundation, wakonza ma patches omwe akukhazikitsa njira ya killswitch ya kernel ya Linux. Mbali yomwe ikuperekedwayi imalola kuletsa nthawi yomweyo magwiridwe antchito ena a kernel. Killswitch cholinga chake ndi kukhala yothandiza poletsa zofooka kwakanthawi mpaka pomwe kernel ikusintha yokhala ndi chokonza chikayikidwa.
Killswitch imayendetsedwa kudzera mu fayilo ya "/sys/kernel/security/killswitch/control", yomwe imakulolani kukonza kutsekereza kwa ma call a kernel function ndi mayina awo. Mwachitsanzo, kuti muletse kufooka kwa Copy Fail, ingowonjezerani lamulo lakuti "engage af_alg_sendmsg -1" ku fayilo yolamulira kuti mulole kutsekereza kwa af_alg_sendmsg function call ndikubwezera khodi yolakwika "-1" m'malo mwake.
Zilembo zilizonse zomwe zimathandizidwa ndi kprobes subsystem zingagwiritsidwe ntchito ngati mayina. Zofooka zambiri zazikulu za kernel zomwe zapezeka posachedwa zimapezeka m'ma subsystem omwe amagwiritsidwa ntchito ndi ogwiritsa ntchito ochepa (monga, AF_ALG, ksmbd, nf_tables, vsock, ax25). Kwa ogwiritsa ntchito ambiri, zovuta za kutayika kwa magwiridwe antchito m'machitidwe ena sizoyenera kugwiritsa ntchito kernel yokhala ndi vuto lodziwika bwino, losasinthidwa mpaka patch itayikidwa. Njira ya killswitch ndiyofunikira kwambiri pankhani ya Dirty Frag vulnerability yomwe ilipo, yomwe exploit idasindikizidwa vutoli lisanakonzedwe mu kernel.
Source: opennet.ru
