4 ms·
You obviously know vastly more about security than I do, but I don't understand how a black box with DMA doesn't implicitly compromise the rest of the device, f
by rosser 8y ago
You obviously know vastly more about security than I do, but I don't understand how a black box with DMA doesn't implicitly compromise the rest of the device, for people whose threat models might include state-level actors — and particularly their shadier bits.
EDIT: Is it just a matter of there being easier/cheaper vectors?
Also, phrasing.
- kasey_junk 8y agohttps://www.synopsys.com/dw/dwtb.php?a=hsic_usb2_device https://www.synopsys.com/dw/dwtb.php?a=hsic_usb2_device Most modern smartphones use usb for baseband comms. I’m no expert but I don’t think the DMA thing hasn’t been true widely for a very long time.
- rosser 8y agoI'm finding product briefs for 4G and 5G basebands listing host DMA capabilities, so it's still enough of a thing to keep vendors offering it.
- tptacek 8y agoYou should use, exclusively, modern iPhones or, if you have an expert to help set it up, a flagship Google Android phone. I'm sure there are lots of off-brand Android phones that have basebands with full DMA access and no meaningful IOMMU configuration.
- pvg 8y agoAnd IOMMUs in places where DMA-ish access is needed.