1.1.2.2.2 Ensure nodev option set on /dev/shm partition

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

- IF - a separate partition exists for /dev/shm.

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.

Impact:

Setting the nodev option prevents device files from being interpreted on the /dev/shm filesystem, which is not expected to contain device files; this typically has no operational impact.

See Also

https://workbench.cisecurity.org/benchmarks/27892

Item Details

Category: ACCESS CONTROL, CONFIGURATION MANAGEMENT, MEDIA PROTECTION

References: 800-53|AC-3, 800-53|AC-5, 800-53|AC-6, 800-53|CM-7(2), 800-53|MP-2, CSCv7|14.6

Plugin: Unix

Control ID: b6f630f6376d99dfbd75794afd08b4fc09497e0b2638a641874c981d05014026