lkml.org 
[lkml]   [2022]   [Jan]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] PCI: ACPI: Allow internal devices to be marked as untrusted
On Fri, Jan 21, 2022 at 03:41:17PM -0600, Bjorn Helgaas wrote:
> [+cc Greg, Jean-Philippe, Mika, Pavel, Oliver, Joerg since they
> commented on previous "external-facing" discussion]
>
> On Wed, Jan 19, 2022 at 04:04:09PM -0800, Rajat Jain wrote:
> > Today the pci_dev->untrusted is set for any devices sitting downstream
> > an external facing port (determined via "ExternalFacingPort" property).
> > This however, disallows any internal devices to be marked as untrusted.
>
> This isn't stated quite accurately. "dev->untrusted" is currently set
> only by set_pcie_untrusted(), when "dev" has an upstream bridge that
> is either external-facing or untrusted.
>
> But that doesn't disallow or prevent internal devices from being
> marked as untrusted; it just doesn't implement that.
>
> > There are use-cases though, where a platform would like to treat an
> > internal device as untrusted (perhaps because it runs untrusted
> > firmware, or offers an attack surface by handling untrusted network
> > data etc).

Who is making this policy decision?

> > This patch introduces a new "UntrustedDevice" property that can be used
> > by the firmware to mark any device as untrusted.

Is this in the ACPI standard? If so, where?

This notion of "trust" for PCI devices is crazy, as I have stated a
number of times before. But at least you are not trying to say kernel
code is trusted or not.

thanks,

greg k-h

\
 
 \ /
  Last update: 2022-01-22 15:47    [W:0.095 / U:0.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site