Bug 1842611 - kernel_lockdown prevents "sensors-detect" from detecting some hardware monitoring chips
Summary: kernel_lockdown prevents "sensors-detect" from detecting some hardware monito...
Keywords:
Status: CLOSED EOL
Alias: None
Product: Fedora
Classification: Fedora
Component: lm_sensors
Version: 31
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Hans de Goede
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2020-06-01 17:09 UTC by Steve
Modified: 2020-11-24 16:37 UTC (History)
4 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
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Clone Of:
Environment:
Last Closed: 2020-11-24 16:37:14 UTC
Type: Bug
Embargoed:


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System ID Private Priority Status Summary Last Updated
Red Hat Bugzilla 1841349 0 unspecified CLOSED man kernel_lockdown refers to non-functional sysrq+x 2021-05-25 16:22:02 UTC

Description Steve 2020-06-01 17:09:44 UTC
Description of problem:

The kernel_lockdown feature prevents "sensors-detect" from detecting some hardware monitoring chips.

The log shows:

May 15 19:56:25 kernel: Lockdown: sensors-detect: /dev/mem,kmem,port is restricted; see man kernel_lockdown.7

Version-Release number of selected component (if applicable):

lm_sensors-3.5.0-6.fc31.x86_64
kernel 5.6.13-200.fc31.x86_64

How reproducible:
Always.

Steps to Reproduce:
Run "sensors-detect" and answer "yes" to everything.

Actual results:
Some hardware monitoring chips are not detected.

Expected results:
All supported hardware monitoring chips are detected.

Alternative 1: Find a way to detect chips without running afoul of the kernel_lockdown feature.

Alternative 2: Document a way to disable the kernel_lockdown feature before running "sensors-detect".

Additional info:

The specific kernel module that is not configured is nct6775.* However, nct6775 loads and works as expected:

$ fgrep 'HWMON_MODULES=' /etc/sysconfig/lm_sensors 
HWMON_MODULES="coretemp nct6775"

$ lsmod | fgrep -m1 'nct6775'
nct6775                77824  0

Motherboard: ASUS All Series/B85M-G R2.0, BIOS 3602 03/23/2018

See, also:

Bug 1841349 - man kernel_lockdown refers to non-functional sysrq+x 

* I know that because I had run "sensors-detect" with kernels that pre-date the kernel_lockdown feature.

Comment 1 Steve 2020-06-01 17:18:08 UTC
For the record, the man page doesn't mention kernel_lockdown:

$ man sensors-detect | grep -i 'lockdown'

$ rpm -q lm_sensors
lm_sensors-3.5.0-6.fc31.x86_64

Comment 2 Hans de Goede 2020-06-02 11:15:25 UTC
Hmm, interesting problem. I've started a discussion on the upstream kernel mailinglist about this:

https://lore.kernel.org/linux-hwmon/0d7e97e0-fe78-163a-cdaf-825b9d0b50ee@redhat.com/

Steve, let me know if you want me to Cc you on my next reply in that thread (which will expose your email address on a couple of very public mailinglists).

Comment 3 Steve 2020-06-02 14:56:58 UTC
Thanks, Hans. Adding kernel support sounds like a good approach, but I don't know enough about kernel internals to contribute usefully, so I have bookmarked the link and won't need to be Cc'ed.

Comment 4 Ben Cotton 2020-11-03 16:43:05 UTC
This message is a reminder that Fedora 31 is nearing its end of life.
Fedora will stop maintaining and issuing updates for Fedora 31 on 2020-11-24.
It is Fedora's policy to close all bug reports from releases that are no longer
maintained. At that time this bug will be closed as EOL if it remains open with a
Fedora 'version' of '31'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version.

Thank you for reporting this issue and we are sorry that we were not 
able to fix it before Fedora 31 is end of life. If you would still like 
to see this bug fixed and are able to reproduce it against a later version 
of Fedora, you are encouraged  change the 'version' to a later Fedora 
version prior this bug is closed as described in the policy above.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events. Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

Comment 5 Ben Cotton 2020-11-24 16:37:14 UTC
Fedora 31 changed to end-of-life (EOL) status on 2020-11-24. Fedora 31 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of
Fedora please feel free to reopen this bug against that version. If you
are unable to reopen this bug, please file a new report against the
current release. If you experience problems, please add a comment to this
bug.

Thank you for reporting this bug and we are sorry it could not be fixed.


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