Information
The nodev mount option specifies that the filesystem cannot contain special devices.
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.
Solution
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.
Example:
tmpfs /dev/shm tmpfs defaults,rw,nosuid,nodev,noexec,relatime 0 0
Run the following command to remount /dev/shm with the configured options:
# mount -o remount /dev/shm
NOTE It is recommended to use tmpfs as the device/filesystem type as /dev/shm is used as shared memory space by applications.