01-11-2018 08:56 AM
Had my first BSOD today on my T440p after three years of operation. Found event log flooded with WHEA-Logger events which started on 1/5 when I installed KB4056892 and updated the BIOS to 2.46. I'm going to uninstall KB4056892 for now, but what is being done to resolve this?
01-11-2018 09:07 AM
I have a slight variation that might help narrow things down:
I have pretty much the same issue here on my T440s: WHEA Logger events pouring in and occasional system lockups - the screen freezes and only option is to power off.
However, the problems started after updating to BIOS 2.46, which I did several days after KB4056892 was already installed. So it seems that it is the combination of the two that causes the problem.
I wish I could recall the previous BIOS version - I'm pretty sure it was in the 2.3x (i.e. between 2.30 and 2.39). I do not have any 3rd party AV - just Windows Defender.
So, should I roll back the KB, or the BIOS?
(Win 10 Pro 64bit 1709. Most used apps: Outlook 2016, FireFox, VS2017, Slack ...)
I tried rolling back my firmware (see earlier post) to no avail. Most likely because microcode updates aren't reversable, so add the two registry values that Elgaard mentioned a few posts up.
This disables the patch for both meltdown flaws (hence the "3", as it is a two-bit value). You're back at risk again by choosing to do so, but we're all adults and make our own choices. And you can re-enable the Microsoft patches once there is a "v2" patch issued by Lenovo and/or Intel by deleting the two values or setting them to "0".
Hopefully someone from Lenovo is monitoring this thread and notifying higher-ups on this issue now.
01-11-2018 09:48 AM
So I did some experimenting with the registry values that Microsoft published to enable/disable the two meltdown flaws.
If I set FeatureSettingsOverride and FeatureSettingsOverrideMask values to '1', I get no more WHEA errors.
Setting these values to '1' enables the fix for CVE-2017-5754 caused NO WHEA errors
Setting these values to '2' enables the fix for CVE-2017-5715 caused WHEA errors.
5754 is the rouge data cache load attack and
5715 is the branch target injection attack
The way I came up with these values is from https://support.microsoft.com/en-us/help/4072698/windows-server-guidance-to-protect-against-the-spec..., subsection "Additional Information", Answer #9
FeatureSettingsOverride represents a bitmap that overrides the default setting and controls which mitigations will be disabled. Bit 0 controls the mitigation corresponding to CVE-2017-5715 and Bit 1 controls the mitigation corresponding to CVE-2017-5754. The bits are set to “Zero” to enable the mitigation and to “One” to disable the mitigation.
FeatureSettingsOverrideMask represents a bitmap mask that is used in conjunction with FeatureSettingsOverride and in this case, we use the value 3 (0x11) which indicates the first two bits that correspond to the available mitigations. This registry key is set to 3 both when we want to enable the mitigations and to disable the mitigations.
00 = 0 Both CVE-2017-5715 and CVE-2017-5754 enabled (WHEA Errors) 01 = 1 CVE-2017-5754 Enabled Only (No WHEA Errors) 10 = 2 CVE-2017-5715 Enabled Only (WHEA Errors) 11 = 3 (No WHEA Errors)
Anyway, instead of disabling BOTH fixes, just disable the fix for 5715 until a patch for the patch is released.
01-11-2018 10:18 AM
I tried a clean Windows 10 Pro (1709) installation with a minimal set of drivers.
The WHEA Errors occur instantly after Windows Update has installed KB4056892.
The combination of Bios 2.46 and KB4056892 must causes the problems.
[Lenovo T440s / Windows 10 Pro (1709) 64 Bit / Bios 2.46]
01-11-2018 10:59 AM
If I set FeatureSettingsOverride and FeatureSettingsOverrideMask values to '1', I get no more WHEA errors....
Confirmed. I left the KB and BIOS alone and just set both keys to 1 on my T440s. No WHEA errors, no lockups so far.
Will await proper fix from Lenovo and/or Microsoft.
01-12-2018 05:06 PM
So - looks like Intel's crapped the bed with some of their microcode patches and has requested Lenovo (and presumably all OEMs) to pull the impacted updates until Intel fixes their 'quality issue'.
Scroll down to the section "Withdrawn CPU Microcode Updates"
Oddly, the T440 and my T540 aren't part of the the withdrawl. So we wait?
01-16-2018 03:25 AM
I have the same phenomenon, and another one:
Together with the BIOS update came a power management driver update.
Now there are windows log messages
The speed of processor 3 in group 0 is being limited by system firmware.
for all cores.