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Bug 1859432

Summary: [unshare] example in man page unshare(1) doesn't work
Product: Red Hat Enterprise Linux 7 Reporter: JianHong Yin <jiyin>
Component: util-linuxAssignee: Karel Zak <kzak>
Status: CLOSED WONTFIX QA Contact: Radka Brychtova <rskvaril>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 7.9CC: xzhou
Target Milestone: rcFlags: pm-rhel: mirror+
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2022-01-22 07:27:04 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description JianHong Yin 2020-07-22 03:36:08 UTC
Description of problem:

example command line in man page unshare(1) does not work:
'''
[root@rhel-7-9-latest ~]$ man unshare | grep -A 8 EXAMPLES
EXAMPLES
       # unshare --fork --pid --mount-proc readlink /proc/self
       1
              Establish a PID namespace, ensure we're PID 1 in it against newly mounted procfs instance.

       $ unshare --map-root-user --user sh -c whoami
       root
              Establish a user namespace as an unprivileged user with a root user within it.
[foo@rhel-7-9-latest ~]$ unshare --map-root-user --user sh -c whoami
unshare: unshare failed: Invalid argument
[foo@rhel-7-9-latest ~]$ lsb_release -sir
RedHatEnterpriseServer 7.9
[foo@rhel-7-9-latest ~]$ uname -r
3.10.0-1157.el7.x86_64
[foo@rhel-7-9-latest ~]$ rpm -qf /usr/bin/unshare
util-linux-2.23.2-65.el7.x86_64
'''

Version-Release number of selected component (if applicable):
util-linux-2.23.2-65.el7.x86_64

How reproducible:
always on RHEL-7

Steps to Reproduce:
1. #run the command line in man page unshare(1)
unshare --map-root-user --user sh -c whoami

Actual results:
'''
[foo@rhel-7-9-latest ~]$ unshare --map-root-user --user sh -c whoami
unshare: unshare failed: Invalid argument
'''

Expected results:
'''
[foo@rhel-8-3-latest ~]$ unshare --map-root-user --user sh -c whoami
root
'''

Additional info:
it works fine on RHEL-8

Comment 5 RHEL Program Management 2022-01-22 07:27:04 UTC
After evaluating this issue, there are no plans to address it further or fix it in an upcoming release.  Therefore, it is being closed.  If plans change such that this issue will be fixed in an upcoming release, then the bug can be reopened.