Umboni wa lingaliro la kufooka kwa nkhaniyi wafalitsidwa. DirtyDecrypt, yomwe imadziwikanso kuti DirtyCBC, kulola wogwiritsa ntchito wopanda mwayi wamba kupeza mwayi woyambira pamakina ena LinuxVuto lili mu code. rxgk magawo ang'onoang'ono RxRPC ndipo ikugwirizana ndi kulemba kwa tsamba chifukwa cha kusowa kwa cheke chokopera pa ntchito ya rxgk_decrypt_skb(). PoC idasindikizidwa pa Meyi 18, 2026, ndi BleepingComputer; PoC yokha yaikidwa mu Malo osungiramo zinthu a gulu la V12.
RxRPC ndi njira yolumikizirana ya kernel network. Linux kudzera pa UDP, zomwe zimapereka mayendedwe odalirika pantchito zakutali. Zolemba za kernel zimanena momveka bwino kuti AFS — Andrew File System ndi chitsanzo cha pulogalamu yomwe imagwiritsa ntchito RxRPC, ndipo protocol yokha imathandizira zokambirana zachitetezo cha kulumikizana. Apa ndi pomwe RxGK, yomwe imagwiritsidwa ntchito pa njira yotetezeka ya RxRPC/AFS, imagwira ntchito.
Malinga ndi kufotokozera kwa V12, DirtyDecrypt ndi mtundu wina wa gulu la zofooka. CopyFail / Dirty Frag / FragnesiaZonsezi zimagwirizana ndi lingaliro lofanana: kusintha kolakwika kwa kernel memory, page cache, ndi buffers kungalole kuti njira yopanda mwayi yakumaloko ikhudze deta yomwe iyenera kukhala yosalembedwa. Pankhani ya DirtyDecrypt, iyi ndi "rxgk pagecache write" chifukwa cha chitetezo cha COW chomwe chilipo mu rxgk_decrypt_skb().
Gulu la V12 likunena kuti lapeza ndi kunena za vutoli. 9 May 2026 zaka, koma osamalira kernel anayankha kuti ndi kachilombo kofanana ndi kachilombo komwe kanakonzedwa kale. Ofufuzawo adasindikiza umboni wa lingaliro, ponena kuti kukonzako kunali kale mu kernel yayikulu.
Nkhani ya ma CVE si yophweka kwenikweni. BleepingComputer ikunena kuti palibe CVE yovomerezeka yapadera ya dzina la DirtyDecrypt panthawi yofalitsa, koma katswiri Will Dormann akugwirizanitsa tsatanetsatane wofalitsidwa ndi V12 ndi CVE-2026-31635, idakonzedwa kumapeto kwa Epulo. NVD imafotokoza CVE-2026-31635 ngati cholakwika mu rxrpc: ntchito ya rxgk_verify_response() idayang'ana molakwika kutalika kwa RESPONSE authenticator, zomwe zingapangitse kuti authenticator yayitali kwambiri iperekedwe ku rxgk_decrypt_skb() ndikupangitsa kuti code ilephereke BUG_ON(len).
Ndiko kuti, mabuku omwe amapezeka pagulu amalumikiza DirtyDecrypt ndi CVE-2026-31635, koma kufotokozera kwa CVE kovomerezeka mu NVD pakadali pano kukuwoneka kopapatiza kwambiri ndipo kumatanthauza makamaka cholakwika choyang'ana kutalika mu rxrpc, osati mwachindunji ku dzina la DirtyDecrypt/DirtyCBC ngati cholowera chosiyana. Chifukwa chake, ndikolondola kwambiri kulemba: DirtyDecrypt mwina ikugwirizana kapena ikugwirizana kwambiri ndi CVE-2026-31635, m'malo monena kuti ndi dzina lovomerezeka la CVE.
Kernel yokhala ndi njira iyi yogwiritsidwa ntchito ikufunika kuti igwire ntchito. CONFIG_RXGK, zomwe zimaphatikizapo thandizo la RxGK kwa kasitomala wa AFS ndi mayendedwe a netiweki. Izi zimachepetsa kwambiri kuchuluka kwa machitidwe omwe akhudzidwa: makamaka, zimakhudza kugawa komwe kumatsatira mwachangu kernel yakumtunda, kuphatikiza Fedora, Chipilala Linux и kutsegulaSUSE TumbleweedBleepingComputer ikugogomezera kuti V12 PoC yofalitsidwayo idayesedwa pa Fedora ndi kernel yayikulu yokha.
DirtyDecrypt idatulukira motsutsana ndi mndandanda wonse wazinthu zofanana Linux Zofooka za LPE. Zomwe zidawululidwa kale Koperani Fayilo mu algif_aead, Chidutswa Chodetsedwa mu zigawo za netiweki, kenako Fragnesia mu XFRM ESP-in-TCP Microsoft kufotokozedwa Dirty Frag ngati kukwezedwa kwa mwayi wakomweko kudzera mu zigawo za esp4, esp6, ndi rxrpc, zomwe zimathandiza wowukira kupeza mwayi wakomweko ndikupeza malo mu dongosololi.
Kuopsa kwa zolakwika zotere ndikuti nthawi zambiri zimagwiritsidwa ntchito pambuyo poti zasweka koyamba: mwachitsanzo, pambuyo poti zasokoneza akaunti ya SSH, chipolopolo cha intaneti, chidebe chotetezeka, kapena wogwiritsa ntchito ntchito wosowa mwayi. Wowukirayo akapeza mwayi wolowera mu root, amatha kuletsa zowongolera zachitetezo, kuwerenga zinsinsi, kusintha zolemba, kugwiritsa ntchito kulimbikira, ndikupita patsogolo kudzera mu zomangamanga.
Ogwiritsa ntchito ma rolling-release distributions omwe angakhudzidwe akulangizidwa kuti ayike zosintha zaposachedwa za kernel. Pa makina omwe zosintha zachangu sizingatheke, mabukuwa amatchula mayankho akanthawi monga kuletsa ma rxrpc modules osagwiritsidwa ntchito ndi zigawo zina zokhudzana nazo. Komabe, njira zoterezi zitha kusokoneza AFS ndi zochitika zina za IPsec/VPN, kotero ziyenera kugwiritsidwa ntchito pokhapokha mutatsimikizira momwe dongosolo linalake likukhudzira.
Pa ma installation ambiri a pa desktop ndi seva, chiopsezocho chingakhale chotsika kuposa Copy Fail: DirtyDecrypt imafuna kasinthidwe ka kernel ndi kuchitidwa kwa code yakomweko. Komabe, pa Fedora, Arch Linux, openSUSE Tumbleweed, ndi machitidwe ena okhala ndi zosintha zachangu za kernel, nkhaniyi ikuyenera kuganiziridwa bwino: si lipoti la chiphunzitso, koma vuto lokhala ndi umboni wofalitsidwa wa lingaliro komanso njira yomveka bwino yopititsira patsogolo mwayi.
Source: linux.org.ru
