Re: [PATCH V32 11/27] x86: Lock down IO port access when the kernel is locked down

[Thomas Gleixner]

On Wed, 3 Apr 2019, Matthew Garrett wrote:

> From: Matthew Garrett <mjg59@xxxxxxxxxxxxx>
> 
> 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.
> 
> This also implicitly locks down the KDADDIO, KDDELIO, KDENABIO and
> KDDISABIO console ioctls.
> 
> Signed-off-by: Matthew Garrett <mjg59@xxxxxxxxxx>
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>