Kwiintsuku ezimbalwa ezidlulileyo iindaba zakhutshwa ukuba Ubungozi buchongiwe kwiNetfilter (Inkqubo esezantsi yeLinux kernel esetyenziselwa ukucoca kunye nokuguqula iipakethi zenethiwekhi), yona ivumela umsebenzisi wasekhaya ukuba afumane amalungelo engcambu kwinkqubonkqu kwisitya esigqunyiweyo.
Umngcipheko we-CVE-2021-22555 yingxaki ebikade ikho ukusukela kernel 2.6.19, yasungulwa kwiminyaka eli-15 eyadlulayo kwaye kubangelwa yi-bug kubaqhubi IPT_SO_SET_REPLACE kunye ne-IP6T_SO_SET_REPLACE, ebangela ukuba isikhukula siphuphume xa kuthunyelwa iiparameter ezihonjiswe ngokukodwa ngefowuni yesikockopt kwimowudi yokuhambelana.
Mhlawumbi abaninzi ngeli xesha bayazibuza ukuba kunokwenzeka njani ukuba isiphoso kwiLinux Kernel singabonakali ixesha elide kwaye impendulo kuloo nto kukuba nangona isiphako esasikho ukusukela kwiLinux 2.6.19, ubungozi bufunyenwe ngekhowudi uphicotho-zincwadi, nangona ikhowudi ye-C ibingaphinde iveliswe kwakhona, ke ayinakuxhatshazwa kuba izixhobo eziyimfuneko zokunyusa amalungelo azifumanekanga ngelo xesha.
Umzekelo ukuxhaswa kweendawo ezingenamagama omsebenzisi ezingenanto zikwi-kernel 3.8. Kwakhona, olunye ulwabiwo luneqhekeza elongeza i-sysctl ukukhubaza iindawo ezingenamagama zomsebenzisi.
Phantsi kweemeko eziqhelekileyo, ingcambu yomsebenzisi kuphela enokubiza i-compat_setsockopt ()kodwa imvume eyimfuneko ukwenza uhlaselo zinokufunyanwa ngumsebenzisi ongenalungelo kwiinkqubo ezinendawo yokusebenza yamagama enikwe amandla.
I-CVE-2021-22555 yiminyaka eli-15 ubudala kwisitaki esibhaliweyo sokubekwa emngciphekweni kwiLinux Netfilter enamandla ngokwaneleyo okudlula kulo lonke ukhuseleko lwanamhlanje kunye nokufezekisa ikhowudi yekernel.
Kananjalo, ichaziwe loo nto umsebenzisi wasekhaya angenza isikhongozeli kunye nomsebenzisi owahlukileyo weengcambu kwaye asebenzise ubungozi aphoí. Umzekelo, "izithuba zomsebenzisi" zibandakanyiwe ngokungagqibekanga ku-Ubuntu nakwiFedora, kodwa hayi kwi-Debian ne-RHEL.
Obu bungozi bunokuxhatshazwa ngokubhala ngaphezulu
m_list->nextIsikhombisimsg_msgulwakhiwo kunye nokufezekisa simahla emva kokusetyenziswa. Oku kunamandla ngokwaneleyo ukuba ikhowudi yakho ye-kernel isebenze ngokudlula kwi-KASLR, i-SMAP, kunye ne-SMEP.
Kwakhona, ingxaki ivela ku xt_compat_target_from_user () umsebenzi ngenxa yokubala okungalunganga kwememori xa kugcinwa izakhiwo ze-kernel emva kokuguqulwa ukusuka kwi-32-bit ukuya kwi-64-bit.
Kananjalo, kuyakhankanywa ukuba Impazamo ivumela ukubhala ii-byte ezine "zero" kuso nasiphi na isikhundla ngaphandle kwesikhuseli yabelwe, inqunyelwe nge-offset 0x4C. Ngenxa yoku, kuyakhankanywa ukuba Eli nqaku liye lanele ukuba lenze ukuxhaphaza evumela ukufumana ingcambu yamalungelo: ngokususa m_list-> Isikhombisi esilandelayo kwisakhelo se-msg_msg, iimeko zenziwe ukufikelela kwidatha emva kokukhulula inkumbulo (emva kokusebenzisa), eyayisetyenziselwa ukufumana ulwazi malunga needilesi kunye utshintsho kolunye ulwakhiwo ngokukhohlisa inkqubo msgsnd () yefowuni.
Ngokumalunga nengxelo yempazamo, njengawo nawuphi na umngcipheko obhaqiweyo, oku kubandakanya inkqubo kunye nengxelo eyenziwe kubaphuhlisi be-kernel ngo-Epreli, emva koko yalungiswa kwiintsuku ezimbalwa kunye nepaki ebandakanyiweyo kulwabiwo lonke oluxhaswayo, ukuze Ulwazi malunga nebug lunokukhutshwa kamva.
Iiprojekthi zeDebian, Arch Linux, kunye neFedora sele zivelisile ukuhlaziywa kwephakheji. Ukuqala ngo-Ubuntu, RHEL kunye nohlaziyo lwe-SUSE kwimisebenzi. Ngenxa yokuba impazamo inzulu, iyaxhaphaza ngokwenza kwaye ivumela ukubaleka kwisitya, UGoogle uqikelele ukufumanisa kwakhe kwi- $ 10,000 kwaye wawuphinda kabini umvuzo kumphandi ochonge ukuba semngciphekweni kunye nokuchonga indlela yokuthintela ukubeka bucala izikhongozeli zeKubernet kwiqela leKCTF.
Uvavanyo, iprototype esebenzayo yokuxhaphaza sele ilungisiwe edlula kwi-KASLR, i-SMAP kunye neendlela zokukhusela ze-SMEP.
Gqibela ukuba unomdla wokwazi okungakumbi ngayo, ungajonga iinkcukacha Kule khonkco ilandelayo.