Intel tau tshaj tawm cov ntaub ntawv hais txog cov chav kawm tshiab ntawm cov ntaub ntawv tawm los ntawm microarchitectural qauv ntawm cov txheej txheem, uas tso cai, los ntawm kev tswj hwm ntawm MMIO (Memory Mapped Input Output) mechanism, los txiav txim cov ntaub ntawv ua tiav ntawm lwm cov CPU cores. Piv txwv li, qhov tsis zoo tso cai rau cov ntaub ntawv raug rho tawm los ntawm lwm cov txheej txheem, Intel SGX enclaves, lossis cov tshuab virtual. Qhov tsis zoo no tsuas yog rau Intel CPUs xwb; cov txheej txheem los ntawm lwm cov tuam txhab lag luam tsis cuam tshuam los ntawm qhov tsis zoo.
Qhov tsis zoo tshwm sim hauv ntau yam Intel CPUs, suav nrog cov txheej txheem raws li Haswell, Skylake, IceLake, Broadwell, Lakefield, Kabylake, Cometlake thiab Rocketlake microarchitectures, nrog rau Xeon EP / EX, Scalable thiab qee qhov Atom server processors. Txhawm rau ua kom muaj kev tawm tsam, kev nkag mus rau MMIO yog xav tau, uas, piv txwv li, tuaj yeem tau txais hauv cov tshuab virtualization uas muab lub peev xwm nkag mus rau MMIO rau cov qhua tuaj yeem tswj hwm los ntawm tus neeg tawm tsam. Kev txhim kho kuj tseem yuav xav tau rau cov tshuab siv Intel SGX (Software Guard Extensions) cais cov kab ke.
Kev thaiv qhov tsis zoo yuav tsum tau hloov kho microcode thiab siv cov txheej txheem kev tiv thaiv software ntxiv raws li kev siv VERW cov lus qhia kom tshem tawm cov ntsiab lus ntawm microarchitectural buffers thaum rov qab los ntawm cov ntsiav mus rau cov neeg siv qhov chaw lossis thaum hloov chaw tswj mus rau cov qhua. Kev tiv thaiv zoo ib yam kuj tseem siv los thaiv cov kev tawm tsam yav dhau los ntawm MDS (Microarchitectural Data Sampling), SRBDS (Special Register Buffer Data Sampling) thiab TAA (Transactional Asynchronous Abort) cov chav kawm.
Nyob rau sab microcode, cov kev hloov pauv uas tsim nyog los siv kev tiv thaiv tau thov hauv lub Tsib Hlis microcode hloov tshiab rau Intel CPUs (IPU 2022.1). Hauv Linux kernel, kev tiv thaiv cov chav kawm tshiab ntawm kev tawm tsam suav nrog hauv kev tso tawm 5.18.5, 5.15.48, 5.10.123, 5.4.199, 4.19.248, 4.14.284, thiab 4.9.319. Txhawm rau txheeb xyuas lub kaw lus raug cuam tshuam rau qhov tsis zoo hauv MMIO thiab ntsuas cov haujlwm ntawm qee yam kev tiv thaiv, cov ntaub ntawv "/sys/devices/system/cpu/vulnerabilities/mmio_stale_data" tau ntxiv rau Linux ntsiav. Txhawm rau tswj kev suav nrog kev tiv thaiv, kernel boot parameter "mmio_stale_data" tau siv, uas tuaj yeem siv qhov tseem ceeb "tag nrho" (ua kom huv ntawm buffers thaum tsiv mus rau tus neeg siv qhov chaw thiab hauv VM), "tag nrho, nosmt" ( raws li "tag nrho" + tseem cuam tshuam SMT / Hyper- Xov) thiab "tawm" (kev tiv thaiv tsis taus). Kev sib cais yog muab rau Xen hypervisor thiab Qubes operating system.
Lub ntsiab lus ntawm cov chav kawm uas tau txheeb xyuas qhov tsis zoo yog tias qee qhov kev ua haujlwm ua rau luam lossis txav cov ntaub ntawv ntxiv tom qab ua tiav ntawm lwm cov CPU cores los ntawm ib qho microarchitectural tsis mus rau lwm qhov. Vulnerabilities nyob rau hauv MMIO tso cai rau cov ntaub ntawv seem no yuav raug xa mus los ntawm kev cais microarchitectural buffers rau daim ntawv thov-pom cov npe lossis CPU buffers. Peb txoj kev tau raug txheeb xyuas rau kev rho tawm cov ntaub ntawv seem los ntawm MMIO:
- DRPW (Device Register Partial Write, CVE-2022-21166) yog ib qho teeb meem nrog kev tuav tsis raug ntawm kev sau rau qee qhov MMIO cov npe. Yog tias qhov luaj li cas ntawm cov ntaub ntawv raug sau tsawg dua qhov loj ntawm cov ntawv sau npe, ces cov ntaub ntawv seem ntawm cov ntawv sau buffers kuj tau theej rau hauv cov ntawv sau npe. Yog li ntawd, cov txheej txheem uas pib ua haujlwm tsis tiav rau MMIO cov ntawv sau npe tuaj yeem tau txais cov ntaub ntawv seem hauv microarchitectural buffers los ntawm kev ua haujlwm ntawm lwm cov CPU cores.
- SBDS (Sib koom Buffers Data Sampling, CVE-2022-21125) yog qhov xau ntawm cov ntaub ntawv seem los ntawm cov kernel-bound filling tsis ua los ntawm kev txav los ntawm qhov nruab nrab buffers uas muaj rau txhua lub kernels.
- SBDR (Shared Buffers Data Read, CVE-2022-21123) - qhov teeb meem zoo ib yam li SBDS, tab sis qhov sib txawv ntawm cov ntaub ntawv seem tuaj yeem xaus rau hauv CPU qauv pom rau cov ntawv thov. SBDS thiab SBDR teeb meem tshwm sim tsuas yog ntawm cov txheej txheem rau cov neeg siv khoom thiab ntawm Intel Xeon E3 server tsev neeg.
Tau qhov twg los: opennet.ru