1.2.5 SELinux Policy Prevents SQL*Plus From Connecting to Oracle Database

If SELinux is enabled, the default SELinux policy prevents the version of SQL*Plus that is installed by the Oracle Instant Client packages from connecting to the Oracle Database.

To work around this issue, use the SQL*Plus binary that is installed by Oracle Database itself, which is located in $ORACLE_HOME/bin. Another workaround is to set SELinux to permissive mode. (Bug ID 25743208)