Re: Wiretapping Linux?

From: linux-os (Dick Johnson)
Date: Wed May 17 2006 - 06:24:00 EST

On Wed, 17 May 2006, Joerg Pommnitz wrote:

> Hello all,
> while I agree with the points made in this discussion that it is harder to
> get a backdoor into Linux I'm left wondering about the whole computing
> system Linux is running on. Modern network card have enough computing
> power to easily run wiretapping that you won't see in the driver code. If
> you are concerned about wiretapping, then the large binary blobs of
> firmware needed to run your peripherals should be of real concern.
> The same is true for the BIOS. Even older CPUs come with a system mode
> that exists outside the realm controlled by the OS.
> Regards
> Joerg

CPUs inside network cards (if any) don't run in the same address-space
as your host CPU, memory, etc. Data is DMAed (set up on the host-CPU
side) to/from this private bus, using the PCI bus. You would need
very extensive cooperative code running on the host CPU (in the
driver) to do anything useful. If you are going to write such
driver code, you don't need the CPU inside the controller card
at all because you are already running with high privileges on
the correct bus.

Dick Johnson
Penguin : Linux version on an i686 machine (5592.89 BogoMips).
New book:

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