Re: Flames over -- Re: Which is simpler? (Was Re: [Suspend2-devel]Re: [ 00/10] [Suspend2] Modules support.)

From: Johannes Berg
Date: Mon Feb 13 2006 - 07:11:27 EST


On Sun, 2006-02-12 at 13:28 -0500, Kyle Moffett wrote:

> /me reads spec. *sigh* Whatever idiocy-committee wrote that spec was
> clearly either smoking crack or living in a fantasy-world (or both).
> An arbitrary unrestricted DMA bus is a massive and painfully obvious
> security hole. Can somebody _please_ shoot the guy that came up with
> that brilliant idea? At least it looks like it's not available if
> the firewire modules aren't loaded, which means that you can prevent
> that sort of attack, and my laptop luckily doesn't load those modules
> at boot just to save a bit of memory.

might not help since your firmware turns on the firewire port to enable
booting from firewire disks.

> Even still, that's just a
> terrible idea. Is there any practical way to restrict DMA and make
> FireWire secure?

load the modules with phys_dma=0

johannes

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