RHEL 9 must mount /dev/shm with the nodev option.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-257863 | RHEL-09-231110 | SV-257863r1155633_rule | CCI-001764 | medium |
| 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. | ||||
| STIG | Date | |||
| Red Hat Enterprise Linux 9 Security Technical Implementation Guide | 2026-02-05 | |||
Details
Check Text (C-257863r1155633_chk)
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 Text (F-61528r1155632_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