4 ms·
It's unclear whether or not these are all strictly DOS. Some seem like they may be exploitable.
by staticassertion 9y ago
It's unclear whether or not these are all strictly DOS. Some seem like they may be exploitable.
- greenhouse_gas 9y agoI thought that it would help even if the USB stack _would_ be secure, as any USB device has direct access to the motherboard/PCI?
- cjbprime 9y agoIt sounds like you're thinking that any device connected to the motherboard or PCI bus has access to read/write arbitrary memory on the host through Direct Memory Access or some other mechanism. This isn't true for a couple reasons: * The PCI bus access is given to the _USB hub_, since that's what's connected to PCI, not to the USB device you plugged in. The USB hub can talk to the USB device using whatever restrictive protocol it wants to. The USB protocol doesn't give DMA access to devices -- it polls registers on the devices for commands and data. * Even if it were a hostile device connected to the PCI bus, modern machines, both desktop-class (e.g. x64) and mobile (e.g. modern ARM cores in cellphones) use IOMMUs to give a virtual view of just the device's own addressable memory to the device, not the full system memory map. (I might be mistaken about some of this, but that's my understanding.)
- justincormack 9y agoMost machines have IOMMUs but they are often not enabled. A lot of them are fairly buggy. Linux generally does not enable them, not sure if osx or Windows does by default.