Bug 1948586

Summary: Ksh allows exiting restricted mode, besides documented as not allowing
Product: Red Hat Enterprise Linux 7 Reporter: Paulo Andrade <pandrade>
Component: kshAssignee: Vincent Mihalkovič <vmihalko>
Status: CLOSED WONTFIX QA Contact: Karel Volný <kvolny>
Severity: low Docs Contact:
Priority: unspecified    
Version: 7.9CC: jeroen.tulp
Target Milestone: rcFlags: pm-rhel: mirror+
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Hardware: All   
OS: Linux   
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: 1948588 (view as bug list) Environment:
Last Closed: 2023-06-28 14:17:27 UTC Type: Bug
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Blocks: 1948588    

Description Paulo Andrade 2021-04-12 14:20:20 UTC
From manual page:

              -r      Enables  the  restricted  shell.   This option cannot be
                      unset once set.

  But one can exit it with:

$ set +r

  One can work an a restricted shell with:

+ Create a ~/.profile that sets PATH to, for example, /rbin
+ Add symbolic links to /rbin, e.g.
  # ln -sf /bin/ls /rbin
+ Remove any unwanted environment variable or function from
  ~/.profile with unset.

  Above works with bash, on basic tests using .bash_profile:

export PATH=/rbin
unset command_not_found_handle

and user shell set to /bin/rbash

  Restricted shells overall are somewhat of a fragile solution,
but if the environment is really very small, it is a somewhat
safe option.

Comment 3 Vincent Mihalkovič 2023-06-28 14:17:20 UTC
Upstream commit: https://github.com/ksh93/ksh/commit/74b4162178c8a2347491b9fd3a22d8e6e1b7e831

Thus this bug is fixed in ksh on all versions of rhel-9 and higher.

Comment 4 RHEL Program Management 2023-06-28 14:17:27 UTC
Development Management has reviewed and declined this request. You may appeal this decision by reopening this request.