chmod: changing permissions of ‘$ORACLE_HOME/bin/extjobO’: Operation not permitted

While applying Oracle database PSU/RU/RUR patches, we always see the following or similar warnings.

OPatch found the word "error" in the stderr of the make command.
Please look at this stderr. You can re-run this make command.
Stderr output:
chmod: changing permissions of ‘/u01/app/oracle/product/12.2.0/dbhome_1/bin/extjobO’: Operation not permitted
make: [iextjob] Error 1 (ignored)