Re: 5.3 boot regression caused by 5.3 TPM changes

From: Hans de Goede <hdegoede@redhat.com>
To: Chris Coulson <chris.coulson@canonical.com>,
	Matthew Garrett <mjg59@google.com>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
	Peter Huewe <peterhuewe@gmx.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>,
	linux-integrity@vger.kernel.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-efi@vger.kernel.org
Subject: Re: 5.3 boot regression caused by 5.3 TPM changes
Date: Tue, 6 Aug 2019 21:27:17 +0200	[thread overview]
Message-ID: <4df2fd32-4b64-4cba-4211-d1008ec01da4@redhat.com> (raw)
In-Reply-To: <0d5bbfe6-a95e-987e-b436-83f754d044ac@canonical.com>

Hi,

On 06-08-19 17:53, Chris Coulson wrote:
> Hi,
> 
> On 04/08/2019 11:00, Hans de Goede wrote:
>> Hi All,
>>
>> While testing 5.3-rc2 on an Irbis TW90 Intel Cherry Trail based
>> tablet I noticed that it does not boot on this device.
>>
>> A git bisect points to commit 166a2809d65b ("tpm: Don't duplicate
>> events from the final event log in the TCG2 log")
>>
>> And I can confirm that reverting just that single commit makes
>> the TW90 boot again.
>>
>> This machine uses AptIO firmware with base component versions
>> of: UEFI 2.4 PI 1.3. I've tried to reproduce the problem on
>> a Teclast X80 Pro which is also CHT based and also uses AptIO
>> firmware with the same base components. But it does not reproduce
>> there. Neither does the problem reproduce on a CHT tablet using
>> InsideH20 based firmware.
>>
>> Note that these devices have a software/firmware TPM-2.0
>> implementation, they do not have an actual TPM chip.
>>
>> Comparing TPM firmware setting between the 2 AptIO based
>> tablets the settings are identical, but the troublesome
>> TW90 does have some more setting then the X80, it has
>> the following settings which are not shown on the X80:
>>
>> Active PCR banks:           SHA-1         (read only)
>> Available PCR banks:        SHA-1,SHA256  (read only)
>> TPM2.0 UEFI SPEC version:   TCG_2         (other possible setting: TCG_1_2
>> Physical Presence SPEC ver: 1.2           (other possible setting: 1.3)
>>
>> I have the feeling that at least the first 2 indicate that
>> the previous win10 installation has actually used the
>> TPM, where as on the X80 the TPM is uninitialized.
>> Note this is just a hunch I could be completely wrong.
>>
>> I would be happy to run any commands to try and debug this
>> or to build a kernel with some patches to gather more info.
>>
>> Note any kernel patches to printk some debug stuff need
>> to be based on 5.3 with 166a2809d65b reverted, without that
>> reverted the device will not boot, and thus I cannot collect
>> logs without it reverted.
>>
>> Regards,
>>
>> Hans
> Do you think this might be the same issue as https://marc.info/?l=linux-integrity&m=155968949020639 <https://marc.info/?l=linux-integrity&m=155968949020639&w=2>?

I was hoping it would be the same issue, so I tested a 5.3 kernel
with that patch added, but unfortunately it still crashes on
the Irbis TW90.

Regards,

Hans