Ukuba sesichengeni kwi-Linux kernel enokubangela ingozi ngokuthumela ipakethe ye-UDP

Kwi-Linux kernel ichongiwe ukuba sesichengeni (I-CVE-2019-11683), ekuvumela ukuba ukude ubangele ukukhanyela kwenkonzo ngokuthumela iipakethi ze-UDP ezenziwe ngokukodwa (iipakethi-yokufa). Ingxaki ibangelwa yimpazamo kwi-udp_gro_receive_segment handler (net/ipv4/udp_offload.c) ngokuphunyezwa kweteknoloji ye-GRO (Generic Receive Offload) kwaye ingakhokelela kukonakala kwemixholo yememori ye-kernel xa kusetyenzwa iipakethi ze-UDP nge-zero padding. (umthwalo ongenanto).

Ingxaki ichaphazela ikernel kuphela 5.0ekubeni inkxaso ye-GRO yeesokethi ze-UDP yayi iphunyeziwe ngoNovemba kulo nyaka uphelileyo kwaye ikwazile ukungena kwi-kernel yamva nje ezinzileyo. Itekhnoloji ye-GRO ikuvumela ukuba ukhawulezise ukusetyenzwa kwenani elikhulu leepakethi ezingenayo ngokudibanisa iipakethi ezininzi kwiibhloko ezinkulu ezingadingi ukusetyenzwa ngokwahlukileyo kwepakethi nganye.
Kwi-TCP, ingxaki ayenzeki, kuba le protocol ayixhasi ukuhlanganiswa kwepakethi ngaphandle kokuhlawula.

Ukuba sesichengeni kuye kwalungiswa kuphela kwifom isiqwenga, uhlaziyo oluchanekileyo alukapapashwa (uhlaziyo lwayizolo lwe-5.0.11 ukulungisa ayiqukwanga). Ukusuka kwiikhithi zokuhambisa, i-kernel 5.0 ikwazile ukubandakanywa kuyo Fedora 30, Ubuntu 19.04, Arch Linux, Gentoo kunye nolunye unikezelo oluqhubekayo oluhlaziyiweyo. Debian, Ubuntu 18.10 nangaphambili, RHEL/CentOS и SUSE/openSUSE ingxaki ayichaphazeli.

Ingxaki yafunyanwa ngenxa yoko sebenzisa Inkqubo yovavanyo ezenzekelayo eyenziwe nguGoogle syzbot kunye ne-analyzer KASAN (KernelAddressSanitizer), ejolise ekuchongeni iimpazamo xa usebenza ngememori kunye neenyaniso zokufikelela kwimemori engalunganga, njengokufikelela kwiindawo zememori ekhululiwe kunye nokubeka ikhowudi kwiindawo zememori ezingajoliswanga ukwenza izinto ezinjalo.

umthombo: opennet.ru