The nodev mount option specifies that the filesystem cannot contain special devices. Rationale: Since the /dev/shm filesystem is not intended to support devices, set this option to ensure that users cannot attempt to create special devices in /dev/shm partitions.
Edit the /etc/fstab file and add nodev to the fourth field (mounting options) for the /dev/shm partition. See the fstab(5) manual page for more information. Run the following command to remount /dev/shm : # mount -o remount,nodev /dev/shm Additional Information: Some distributions mount /dev/shm through other means and require /dev/shm to be added to /etc/fstab even though it is already being mounted on boot. Others may configure /dev/shm in other locations and may override /etc/fstab configuration. Consult the documentation appropriate for your distribution.