Cilmi-baarayaal ka socda kooxda Google Project Zero ayaa daabacday hab looga faa'iidaysto nuglaanta (CVE-2020-29661) ee hirgelinta TIOCSPGRP ioctl maamulaha nidaamka tty subsystem ee kernel Linux, waxayna sidoo kale si faahfaahsan u baadheen hababka ilaalinta ee xannibi kara sida baylahda.
Cayayaanka dhibaatada keenaya waxa lagu hagaajiyay kernel Linux bishii Disembar 3 ee sanadkii hore. Dhibaatadu waxay ka muuqataa kernels ilaa nooca 5.9.13, laakiin inta badan qaybinta ayaa hagaajisay dhibaatada ku saabsan cusboonaysiinta xirmooyinka kernel ee la bixiyay sannadkii hore (Debian, RHEL, SUSE, Ubuntu, Fedora, Arch). Nuglaanta la midka ah (CVE-2020-29660) ayaa isla mar la isla dhex marayey laga helay hirgelinta wicista TIOCGSID ioctl, laakiin sidoo kale mar hore ayaa meel walba lagu hagaajiyay.
Dhibaatadu waxa sababa khalad marka la dhigayo qufulka, taasoo horseedaysa xaalad jinsiyadeed ee darawalada/tty/tty_jobctrl.c code, kaas oo loo isticmaalay in lagu abuuro xaalado bilaash ah oo bilaash ah oo laga faa'iidaysto booska isticmaalaha iyada oo loo marayo faragelinta ioct. wac TIOCSPGRP. Ka faa'iidaysiga shaqo ayaa lagu soo bandhigay mudnaanta sare u qaadida Debian 10 oo leh kernel 4.19.0-13-amd64.
Isla mar ahaantaana, maqaalka la daabacay ayaa diiradda saaraya farsamada abuurista ka faa'iidaysiga shaqada, laakiin halkii ay ka ahaan lahayd qalabyada ka jira kernel si looga hortago dayacanka noocaas ah. Gabagabadu maaha mid raaxo leh, hababka sida qaybinta xusuusta ee tuubada iyo xakamaynta helitaanka xusuusta ka dib marka la sii daayo ayaan loo isticmaalin ficil ahaan, sababtoo ah waxay keenaan hoos u dhac ku yimaada waxqabadka, iyo ilaalinta ku salaysan CFI (Control Flow Integrity), kaas oo xannibaadda ka faa'iidaysiga marxaladaha dambe ee weerarka, waxay u baahan tahay horumar.
Markaad tixgelinayso waxa isbeddel ku samayn kara muddada dheer, mid ka muuqda waa isticmaalka falanqeeyayaasha horumarsan ama isticmaalka luqadaha xusuusta-ammaan ah sida Rust iyo C lahjadaha leh tilmaamo qani ah (sida Hubi C) si loo hubiyo u sheeg inta lagu jiro marxaladda dhismaha, qufulka, walxaha iyo tilmaamayaasha. Hababka ilaalinta waxa kale oo ka mid ah hawlgelinta qaabka argagaxa_on_oops, u beddelashada qaab-dhismeedka kernel-ka qaab-akhris-kaliya, iyo xaddididda gelitaanka wicitaannada nidaamka iyadoo la adeegsanayo habab ay ka mid yihiin seccomp.
Source: opennet.ru