Kua whakawhanakehia e ngā kairangahau o ētahi whare wānanga i te US me Ahitereiria ngā whakaeke e rua o te akomanga Rowhammer—GDDRHammer me GeForge—e āhei ai te pirau o ngā moka takitahi i roto i ngā maramara mahara ataata GDDR i te wā e whakahaerehia ana he kernel CUDA kāore i te whai mana i runga i te GPU NVIDIA. He rerekē ki te tikanga GPUHammer i whakaatuhia i te tau kua hipa, kāore ēnei whakaeke hou e herea noa ki te pā ki ngā raraunga kua tukatukahia i roto i te mahara GPU engari e āhei ai te urunga katoa ki ngā mahara matua katoa i roto i te wāhi wāhitau CPU. I whakaatuhia e ngā kairangahau ngā mahi tinihanga e tuku ana i te urunga pakiaka ki te pūnaha manaaki i te wā e whakahaerehia ana he kernel CUDA kāore i te whai mana i runga i te GPU.
Ka pau wawe ngā pūtau mahara ataata motuhake kāore e taea e ngā kaiwhakaeke te uru atu, ka whakarerekē i ngā moka kua rongoatia i roto i aua pūtau. Ka tutuki te pānui me te tuhi ki te mahara i roto i te wāhi wāhitau CPU mā te pokanoa ki te tohatoha mahara GPU (cudaMalloc) hei wawahi i te wehenga mahara GPU me te mahere i ngā wāhitau GPU mariko ki ngā wāhitau āhua noa i roto i te mahara GPU tūturu, i te mahara CPU rānei.
Ka mahia te whakaeke mā te whakakino i ngā uara moka i roto i te mahara ataata, e penapena ana i ngā ripanga whārangi o te GPU e kawenga ana mō te whakamāori i ngā wāhitau mariko ki ngā wāhitau tūturu. Ko te rerekētanga i waenga i ngā whakaeke GDDRHammer me GeForge ko te tikanga GDDRHammer ka whakarerekē i te Ripanga Whārangi Taumata Whakamutunga (PT), ko te tikanga GeForge ka whakarerekē i te Whaiaronga Whārangi Taumata Whakamutunga (PD0).
I roto i ētahi atu mea, ka whakamahia ngā ripanga whakamāori wāhitau kua tohua hei whakarite i te urunga tika o te GPU ki te mahara CPU, nō reira, mā te whakarerekē i te wāhitau i roto i te ripanga whārangi GPU ki tētahi wāhitau ā-tinana i roto i te RAM matua me te whakatakoto i te haki APERTURE, e whakahohe ana i te aratau mahere mahara CPU, ka taea te pānui me te tuhi raraunga e uru atu ana ki te mahara matua mā te pahi PCIe me te IOMMU kua monokia (kua monokia e te taunoa).
I whakaaturia ngā whakaeke angitu ki ngā kāri whakairoiro ngaio NVIDIA RTX A6000 mahi-teitei i runga i te hoahoanga iti o Ampere (ka tīmata te utu o ngā kāri hou i te $6850, ko ngā kāri kua whakamahia i te $4000) me ngā tauira NVIDIA RTX 3060 kaihoko ($250-$300). Ko te tikanga kua whakawhanakehia mō te karo i te tiakitanga o Rowhammer, me te whakamahi i ngā āheinga whakarara o te GPU, i taea ai te pikinga 64-ngā wā i roto i te tere pirau pūtau ki te whakataurite ki ngā whakaeke o mua. Hei mahi rangitahi hei aukati i ngā whakaeke, ka taea te whakahohe i te aratau Waehere Whakatika Hapa (ECC) mā te whakamahi i te whakahau "nvidia-smi -e 1", engari ka puta he utu tāpiri, ā, ka taea pea te karo mā te whakamahi i ngā tikanga whakaeke pēnei i a ECCploit me ECC.fail.
Ka taea e te whakaeke RowHammer te whakakorikori i nga ihirangi o nga moka takitahi o te mahara DRAM ma te panui i nga raraunga mai i nga pūtau mahara tata. I te mea ko te mahara DRAM he huinga rua-ahua o nga pūtau, kei roto i ia o te punga me te transistor, ko te mahi panui tonu o te waahi mahara kotahi ka arahi ki nga huringa ngaohiko me nga kohikohiko, ka iti te ngaro o te utu o nga pūtau tata. Mena he nui te kaha o te panui, katahi ka ngaro te nui o te utu o te pūtau tata e kore e whai wa ki te huringa whakamau hou ki te whakahoki i tona ahuatanga taketake, ka puta he huringa o te uara o nga raraunga kua rongoa ki roto i te pūtau.
I te tau 2014, i whakaarohia te tikanga whakaeke a Rowhammer, ā, i puta ai he whakataetae i waenganui i ngā kairangahau haumarutanga me ngā kaihanga taputapu: i ngana ngā kaihanga maramara mahara ki te aukati i te ngoikoretanga, i te wā i kitea ai e ngā kairangahau he huarahi hou hei karo i tēnei. Hei tauira, hei tiaki i a Rowhammer, i tāpirihia e ngā kaihanga maramara te tikanga TRR (Target Row Refresh), engari i kitea ko tēnei anake i aukati i te pirau pūtau i roto i ngā take motuhake, ā, kāore i tiaki i ngā āhuatanga whakaeke katoa. I whakawhanakehia ngā tikanga whakaeke mō ngā maramara DDR3, DDR4, me DDR5 i runga i ngā pūnaha me ngā tukatuka Intel, AMD, me ARM, tae atu ki te mahara GDDR i roto i ngā GPU NVIDIA. I tua atu, i kitea he tikanga hei karo i te whakatikatika hapa ECC, ā, i whakaarohia ngā tikanga whakaeke mō ngā whakaeke whatunga me te whakahaere i te waehere JavaScript i roto i te pūtirotiro.
Source: opennet.ru
