RHEL 9 must mount /dev/shm with the nodev option.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-257863SRG-OS-000368-GPOS-00154RHEL-09-231110SV-257863r1155633_rule2025-11-242
Description
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented.
ℹ️ Check
Verify "/dev/shm" is mounted with the "nodev" option with the following command: $ findmnt /dev/shm TARGET SOURCE FSTYPE OPTIONS /dev/shm tmpfs tmpfs rw,nodev,nosuid,noexec,seclabel If the mount options for /dev/shm does not include nodev, this is a finding.
✔️ Fix
Configure "/dev/shm" to mount with the "nodev" option. Modify "/etc/fstab" to use the "nodev" option on the "/dev/shm" file system. To reload all implicit mount units and update the dependency graph so that new options will apply correctly at next remount, run the following command: $ sudo systemctl daemon-reload Use the following command to apply the changes immediately without a reboot: $ sudo mount -o remount /dev/shm