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Remember all those components can't "talk" directly to other components. They must all go through the CPU. So if your graphics card want's to make an internet c
by turblety 9y ago
Remember all those components can't "talk" directly to other components. They must all go through the CPU. So if your graphics card want's to make an internet connection, it must go to the CPU which will then go to the network device.
So if you don't have control over a peripheral (say your GPU for example) then yes, it could be doing things you have no control over. But it can't interfere with anything else unless the CPU says so.
But if you don't have control over your CPU, the "central" processing unit, then it's game over.
- bitwize 9y agoEver hear of DMA, dude?
- turblety 9y agoIsn't that a feature of the CPU though? *edit sorry I am wrong. DMA seems to bypass the CPU [1] 1. https://www.csoonline.com/article/2607924/security/stop-sneaky-hackers-from-launching-dma-attacks.html https://www.csoonline.com/article/2607924/security/stop-snea...
- godelmachine 9y agoI was about to correct you when you edited your own comment !! :)
- j_coder 9y agoNot having a central controller multiple subsystem vendors would have to cooperate using an agreed DMA communication protocol to monitor you and send the information back using the wifi/ethernet chip. Possible but unlikely.
- jnwatson 9y agoThe DMA communication protocol is already defined. It is part of PCIExpress.
- walterbell 9y agoOn the iMac Pro, will PCI devices be able to DMA into both the Intel and ARM CPUs? Is there a single IOMMU which will arbitrate DMA for both CPUs?
- jnwatson 9y agoThe IOMMU functionality is built into the Platform Controller Hub, which is between the baseboard management controller (the ARM) and the main processor. Theoretically it would be possible to prevent DMA between the two, but it is highly doubtful Apple would program it that way.
- wang_li 9y agoThis is what an IOMMU is for.
- klodolph 9y agoYour Ethernet controller and hard drive controller don’t really need to talk to anything else. If either is compromised, it’s already bad.