Re: [PATCH 06/12] x86: Require CAP_COMPROMISE_KERNEL for IO portaccess

From: H. Peter Anvin
Date: Tue Mar 19 2013 - 21:00:43 EST

On 03/18/2013 02:32 PM, Matthew Garrett wrote:
> IO port access would permit users to gain access to PCI configuration
> registers, which in turn (on a lot of hardware) give access to MMIO register
> space. This would potentially permit root to trigger arbitrary DMA, so lock
> it down by default.

Again, if you are going to do this, just kill bloody RAWIO. Quite
frankly saying brainfucked SCSI drivers have abused it doesn't hold
water, because as far as you know those same commands can trigger
arbitrary DMA activity.


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