linux-kernel - Re: [PATCH v3] PCI: Detect and trust built-in Thunderbolt chips

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240823050120.GJ1532424@black.fi.intel.com>
Date: Fri, 23 Aug 2024 08:01:20 +0300
From: Mika Westerberg <mika.westerberg@...ux.intel.com>
To: Mario Limonciello <mario.limonciello@....com>
Cc: Esther Shimanovich <eshimanovich@...omium.org>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Rajat Jain <rajatja@...gle.com>,
	"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
	iommu@...ts.linux.dev, Lukas Wunner <lukas@...ner.de>,
	linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] PCI: Detect and trust built-in Thunderbolt chips

Hi,

On Thu, Aug 22, 2024 at 10:56:44AM -0500, Mario Limonciello wrote:
> > > Here's the snippet from the kernel log with the patch in place.  You can see
> > > it flagged 00:02.0 as untrusted and removable, but it definitely isn't.
> > 
> > Is it marked as ExternalFacingPort in the ACPI tables?
> 
> No; it doesn't have an ACPI companion device.

Hm, how can it pass this then?

static bool pcie_is_tunneled(struct pci_dev *pdev)
{
	...
	/* Internal PCIe devices are not tunneled. */
	if (!root->external_facing)
		return false;
	...

Would you mind adding some debug statements there so we can see
(hopefully) what goes wrong?

The intention is that pcie_switch_directly_under() is only called on
Intel pre-USB4 discrete controllers (well and Maple Ridge as that's
still using the Connection Manager firmware).