Bug 1662922

Summary: SELinux is preventing sensord from 'getattr' accesses on the file /sys/devices/platform/thinkpad_hwmon/hwmon/hwmon2/fan1_input.
Product: [Fedora] Fedora Reporter: accounts
Component: selinux-policyAssignee: Lukas Vrabec <lvrabec>
Status: CLOSED ERRATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: high    
Version: 29CC: dwalsh, lvrabec, mgrepl, mmalik, plautrba, zpytela
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard: abrt_hash:939317a1c5c4720ddba9131048377695576c60cc53d8069a23b0e559f1719393;
Fixed In Version: selinux-policy-3.14.2-46.fc29 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2019-01-17 02:16:57 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description accounts 2019-01-02 12:27:45 UTC
Description of problem:
Normal usage of ThinkPad (browsing the Internet)
SELinux is preventing sensord from 'getattr' accesses on the file /sys/devices/platform/thinkpad_hwmon/hwmon/hwmon2/fan1_input.

*****  Plugin catchall (100. confidence) suggests   **************************

If you believe that sensord should be allowed getattr access on the fan1_input file by default.
Then you should report this as a bug.
You can generate a local policy module to allow this access.
Do
allow this access for now by executing:
# ausearch -c 'sensord' --raw | audit2allow -M my-sensord
# semodule -X 300 -i my-sensord.pp

Additional Information:
Source Context                system_u:system_r:lsmd_t:s0
Target Context                system_u:object_r:sysfs_t:s0
Target Objects                /sys/devices/platform/thinkpad_hwmon/hwmon/hwmon2/
                              fan1_input [ file ]
Source                        sensord
Source Path                   sensord
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           
Target RPM Packages           
Policy RPM                    selinux-policy-3.14.2-44.fc29.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Permissive
Host Name                     (removed)
Platform                      Linux (removed) 4.19.9-300.fc29.x86_64 #1 SMP Thu
                              Dec 13 17:25:01 UTC 2018 x86_64 x86_64
Alert Count                   8
First Seen                    2019-01-02 10:40:03 CET
Last Seen                     2019-01-02 13:20:03 CET
Local ID                      18f856b0-5b6f-46fe-834a-5b0a57d6490a

Raw Audit Messages
type=AVC msg=audit(1546431603.637:435): avc:  denied  { getattr } for  pid=1411 comm="sensord" path="/sys/devices/platform/thinkpad_hwmon/hwmon/hwmon2/fan1_input" dev="sysfs" ino=29631 scontext=system_u:system_r:lsmd_t:s0 tcontext=system_u:object_r:sysfs_t:s0 tclass=file permissive=1


Hash: sensord,lsmd_t,sysfs_t,file,getattr

Version-Release number of selected component:
selinux-policy-3.14.2-44.fc29.noarch

Additional info:
component:      selinux-policy
reporter:       libreport-2.9.7
hashmarkername: setroubleshoot
kernel:         4.19.9-300.fc29.x86_64
type:           libreport

Comment 1 Milos Malik 2019-01-07 08:15:59 UTC
The sensord process should not run as lsmd_t, but it does, because SELinux policy contains an incorrect file context pattern:

# semanage fcontext -l | grep sensord-service
/usr/libexec/lm_sensors/sensord-service-wrapper    regular file       system_u:object_r:lsmd_exec_t:s0 
# 

The file context pattern should look this way:

# semanage fcontext -l | grep sensord-service
/usr/libexec/lm_sensors/sensord-service-wrapper    regular file       system_u:object_r:sensord_exec_t:s0 
# 

Because lsmd_t is dedicated to lib storage management processes and it has nothing to do with sensord.

Comment 2 accounts 2019-01-07 09:09:47 UTC
If it helps, system was originally setup at Fedora 25, upgraded to 27 and now 29.
How would I change the SE context of the system service?

Comment 3 Milos Malik 2019-01-07 09:44:39 UTC
# semanage fcontext -a -t sensord_exec_t /usr/libexec/lm_sensors/sensord-service-wrapper

Unfortunately, above-mentioned file context pattern does not solve the problem completely. Following SELinux rules are needed too:

# cat mypolicy.cil 
( allow sensord_t passwd_file_t ( file ( getattr open read )))
( allow sensord_t sensord_exec_t ( file ( execute_no_trans )))
( allow sensord_t shell_exec_t ( file ( map execute )))
( allow sensord_t sssd_public_t ( dir ( search )))
( allow sensord_t sssd_public_t ( file ( getattr open read map )))
( allow sensord_t sssd_t ( unix_stream_socket ( connectto )))
( allow sensord_t sssd_var_lib_t ( dir ( search )))
( allow sensord_t sssd_var_lib_t ( sock_file ( write )))
# semodule -i mypolicy.cil
#

I'm using this ^^^ until an official fix becomes available.

Comment 4 Lukas Vrabec 2019-01-09 12:28:59 UTC
commit 8e8625f44d6144fe70c2c3a335ef622b4052c16a (HEAD -> rawhide)
Author: Lukas Vrabec <lvrabec>
Date:   Wed Jan 9 13:28:28 2019 +0100

    Change label of /usr/libexec/lm_sensors/sensord-service-wrapper from lsmd_exec_t to sensord_exec_t BZ(1662922)

Comment 5 Fedora Update System 2019-01-13 15:45:17 UTC
selinux-policy-3.14.2-46.fc29 has been submitted as an update to Fedora 29. https://bodhi.fedoraproject.org/updates/FEDORA-2019-6a20cfef61

Comment 6 Fedora Update System 2019-01-14 03:03:28 UTC
selinux-policy-3.14.2-46.fc29 has been pushed to the Fedora 29 testing repository. If problems still persist, please make note of it in this bug report.
See https://fedoraproject.org/wiki/QA:Updates_Testing for
instructions on how to install test updates.
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2019-6a20cfef61

Comment 7 Fedora Update System 2019-01-17 02:16:57 UTC
selinux-policy-3.14.2-46.fc29 has been pushed to the Fedora 29 stable repository. If problems still persist, please make note of it in this bug report.