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Bug
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Resolution: Done-Errata
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Undefined
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rhel-8.7.0
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tpm2-tss-2.3.2-6.el8
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None
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None
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rhel-sst-kernel-security
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ssg_core_kernel
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9
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14
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None
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QE ack, Dev ack
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False
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No
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None
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Release Note Not Required
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Unspecified
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None
Description of problem:
========================
- The home directory of tss account is /dev/null
This causes issue with CIS 8 benchmarking
Version-Release number of selected component (if applicable):
========================
- RHEL 8.x , All versions
- This also exist in RHEL 7 and RHEL 9
How reproducible:
100%
Steps to Reproduce:
========================
1. Check the home directory for tss user
Actual results:
========================
- tss user has `/dev/null` as home directory
~~~
$ grep tss /etc/passwd
tss:x:59:59:Account used by the trousers package to sandbox the tcsd daemon:/dev/null:/sbin/nologin
~~~
Expected results:
========================
- It could have been `/` anyway the `/sbin/nologin` is set but not `/dev/null`
Additional info:
========================
- The rationale specified for the compliance in CIS 8 benchmarking:
~~~
If the user's home directory does not exist or is unassigned, the user will be placed in "/"
and will not be able to write any files or have local environment variables set
~~~
- Benchmarking follows this scrip to find the 'tss' user and flags it as not as per compliance
~~~
grep -E -v '^(halt|sync|shutdown)' /etc/passwd | awk -F: '($7 != "'"$(which nologin)"'" && $7 != "/bin/false") { print $1 " " $6 }' | while read -r user dir; do
if [ ! -d "$dir" ]; then
echo "The home directory ($dir) of user $user does not exist."
fi
done
~~~
- The explanation I found is :
~~~
tss account is used by the trousers package to sandbox the tcsd daemon.
trousers RPM is the part of OS installation.
tss account doesn't need a home directory, so the default value is /dev/null, which will not cause any issue.
In addition, because tss account doesn't need to login to the system, it has /sbin/nologin assigned.
~~~
- clones
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RHEL-9099 The 'tss' account home directory '/dev/null/' causes issues for CIS 8 benchmark adherence
- Closed
- links to
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RHBA-2023:124570 tpm2-tss bug fix and enhancement update
- mentioned on