Jenkins maven java 7 permission issue

Do you run Jenkins manually or via service?

It's not recommended to run it manually via java -jar /usr/share/jenkins/jenkins.war but with service jenkins start|stop.

When you manually start, it'll change owner to user which started jenkins.war via java, service runs under user:group jenkins:jenkins.

Default path for service Jenkins (Debian/Ubuntu) should be /var/lib/jenkins/jobs/<ProjectName>/workspace and everything inside /var/lib/jenkins/ must be owned by user jenkins and group jenkins:

chown -R jenkins:jenkins /var/lib/jenkins/

Also check if you have a properly installed and configured JDK inside your Jenkins project.