alt Hacker News...huh, I was wondering why serial machine code prankster xoreaxeaxeax was keeping lists of extremely long-running instructions.
Hopefully this is at least only possible in kernel mode, right?
Right?!
Replies
xxpor • today at 4:59 PM
Maybe with vfio/igb_uio/uio_pci_generic? Still root level access.
PunchyHamster • today at 7:39 PM
Given that you can connect essentially PCIe devices thru USB it is probably exploitable?
Find out which device is accessible to user and does MMIO, emulate it on FPGA, make it slooooooooow. All it needs to do is for driver to trigger a "right" access". GPU comes to mind
Is it really a long running instruction? I mean, obviously yes, but what makes it slow is that it's doing an MMIO copy from a slow source. It's like a read(2) system call being "slow" because the fd is associated with a socket to the moon.