Kees Cook, tsohon babban jami'in tsarin kernel.org kuma jagoran Ƙungiyar Tsaro ta Ubuntu, yanzu yana aiki a Google akan tabbatar da Android da ChromeOS, ya buga saitin faci don ba da izini a cikin tarin kwaya lokacin sarrafa kiran tsarin. Faci yana inganta tsaro na kwaya ta hanyar canza wurin zama, yana sa hare-hare kan tarin ya fi wahala da rashin nasara. Aiwatar da farko tana goyan bayan ARM64 da x86/x86_64 masu sarrafawa.
Asalin ra'ayin facin yana cikin aikin PaX RANDKSTACK. A cikin 2019, Elena Reshetova, injiniyan injiniya daga Intel, yayi ƙoƙarin ƙirƙirar aiwatar da wannan ra'ayin wanda ya dace da haɗawa cikin babban kwaya na Linux. Daga baya, Kees Cook ya ɗauki matakin, wanda ya gabatar da aiwatarwa wanda ya dace da babban sigar kwaya. Ana shirin haɗa facin a matsayin wani ɓangare na sakin 5.13. Za a kashe yanayin ta tsohuwa. Don kunna shi, ana gabatar da sigar layin umarni na kernel “randomize_kstack_offset=on/offset” da CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT saitin. An kiyasta abin da ke sama na kunna yanayin a kusan asarar aiki 1%.
Ma'anar kariyar da aka ba da shawarar ita ce zaɓin bazuwar tari don kowane kiran tsarin, wanda ya sa ya zama da wuya a iya ƙayyade tsarin tari a cikin ƙwaƙwalwar ajiya, ko da bayan karɓar bayanan adireshin, tun da tsarin tsarin na gaba zai canza adireshin tushe na tari. Ba kamar aiwatar da PaX RANDKSTACK ba, a cikin facin da aka gabatar don haɗawa a cikin kwaya, ba a yin bazuwar ba a matakin farko ba (cpu_current_top_of_stack), amma bayan saita tsarin pt_regs, wanda ya sa ba zai yiwu a yi amfani da hanyoyin tushen ptrace don tantance bazuwar biya ba. a lokacin dogon kira tsarin kira.
source: budenet.ru