AlmaLinux OS 9 must restrict access to the kernel message buffer.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-269425 | SRG-OS-000132-GPOS-00067 | ALMA-09-041050 | SV-269425r1117266_rule | 2026-02-27 | 1 |
Description
Restricting access to the kernel message buffer limits access to only root. This prevents attackers from gaining additional system information as a nonprivileged user.
Satisfies: SRG-OS-000132-GPOS-00067, SRG-OS-000138-GPOS-00069
ℹ️ Check
Verify AlmaLinux OS 9 is configured to restrict access to the kernel message buffer with the following commands:
Check the status of the kernel.dmesg_restrict kernel parameter.
$ sysctl kernel.dmesg_restrict
kernel.dmesg_restrict = 1
If "kernel.dmesg_restrict" is not set to "1" or is missing, this is a finding.
Check that the configuration files are present to enable this kernel parameter.
$ /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F kernel.dmesg_restrict | tail -1
kernel.dmesg_restrict = 1
If "kernel.dmesg_restrict" is not set to "1" or is missing, this is a finding.
✔️ Fix
Configure AlmaLinux OS 9 to restrict access to the kernel message buffer with the following command:
$ echo "kernel.dmesg_restrict = 1 > /etc/sysctl.d/60-dmesg.conf"
Load settings from all system configuration files with the following command:
$ sysctl --system