RHEL 9 must be configured so that all system device files are correctly labeled to prevent unauthorized modification.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-257932 | RHEL-09-232260 | SV-257932r1014838_rule | Medium |
| Description |
| If an unauthorized or modified device is allowed to exist on the system, there is the possibility the system may perform unintended or unauthorized operations. |
| STIG | Date |
| Red Hat Enterprise Linux 9 Security Technical Implementation Guide | 2024-12-04 |
Details
| Check Text (C-61673r925781_chk) |
| Verify that all system device files are correctly labeled to prevent unauthorized modification. List all device files on the system that are incorrectly labeled with the following commands: Note: Device files are normally found under "/dev", but applications may place device files in other directories and may necessitate a search of the entire system. # find /dev -context *:device_t:* \( -type c -o -type b \) -printf "%p %Z\n" # find /dev -context *:unlabeled_t:* \( -type c -o -type b \) -printf "%p %Z\n" Note: There are device files, such as "/dev/vmci", that are used when the operating system is a host virtual machine. They will not be owned by a user on the system and require the "device_t" label to operate. These device files are not a finding. If there is output from either of these commands, other than already noted, this is a finding. |
| Fix Text (F-61597r1014837_fix) |
| Restore the SELinux policy for the affected device file from the system policy database using the following command: $ sudo restorecon -v <device_path> Substitute "<device_path>" with the path to the affected device file (from the output of the previous commands). An example device file path would be "/dev/ttyUSB0". If the output of the above command does not indicate that the device was relabeled to a more specific SELinux type label, then the SELinux policy of the system must be updated with more specific policy for the device class specified. If a package was used to install support for a device class, that package could be reinstalled using the following command: $ sudo dnf reinstall <package_name> If a package was not used to install the SELinux policy for a given device class, then it must be generated manually and provide specific type labels. |