Password of the oracle user in oracle linux?
The oracle-rdbms-server-12cR1-preinstall package includes a bash script that creates the oracle user, if not already existing, using the useradd command.

In this case in log file /var/log/oracle-rdbms-server-12cR1-preinstall/results/orakernel.log you should see this entry:


  Please set password for oracle user


You can run the following command as root to assign a password:

# passwd oracle