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On RHEL 7 systems with a TMOUT policy defined via /etc/profile.d/tmout.sh, sourcing /etc/bashrc may trigger a readonly variable warning:

/etc/profile.d/tmout.sh: line 1: TMOUT: readonly variable

Observed during SSH invocation:

ssh root@<host> ". /etc/bashrc" -q

The TMOUT policy is defined as:

# /etc/profile.d/tmout.sh
export TMOUT=900
readonly TMOUT
 

Behavior indicates that the script is executed more than once within the same shell lifecycle. Since TMOUT is already marked readonly, subsequent assignments fail.

Later RHEL releases include double-sourcing protection inside /etc/bashrc (for example BASHRCSOURCED guard), which prevents this condition. RHEL 7 lacks equivalent logic.

Steps to Reproduce

1. Configure TMOUT policy:

cat /etc/profile.d/tmout.sh
export TMOUT=900
readonly TMOUT
 

2. Start SSH session that explicitly sources bashrc:

ssh root@<host> ". /etc/bashrc"

Observe warning:

TMOUT: readonly variable

Expected Result

Shell initialization should not attempt to reassign readonly variables during repeated sourcing paths.

Actual Result

Readonly variable warning appears when initialization scripts are executed multiple times.

Impact

Cosmetic warning. No functional impact. TMOUT enforcement remains correct.