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RHEL 9 must prevent the loading of a new kernel for later execution.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-257799RHEL-09-213020SV-257799r1106273_ruleCCI-003992medium
Description
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Disabling kexec_load prevents an unsigned kernel image (that could be a windows kernel or modified vulnerable kernel) from being loaded. Kexec can be used subvert the entire secureboot process and should be avoided at all costs especially since it can load unsigned kernel images. The sysctl --system command will load settings from all system configuration files. All configuration files are sorted by their filename in lexicographic order, regardless of the directories in which they reside. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. Files are read from directories in the following list from top to bottom. Once a file of a given filename is loaded, any file of the same name in subsequent directories is ignored. /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf Satisfies: SRG-OS-000480-GPOS-00227, SRG-OS-000366-GPOS-00153
STIGDate
Red Hat Enterprise Linux 9 Security Technical Implementation Guide2025-05-14

Related Frameworks

2 mappings across 3 frameworks
SCF0 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (1) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

CHG-04.2Signed Components
0.50
NIST 800-530 mappings

No source states a mapping between these directly.

Also reachable in 2 hops (13) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

AC-2(10)Shared and Group Account Credential Change
1.00
AU-4Audit Log Storage Capacity
1.00
CM-14Signed Components
1.00
CM-5(1)Automated Access Enforcement and Audit Records
1.00
CM-5(3)Signed Components
1.00
CM-7Least Functionality
1.00
CM-7(5)Authorized Software — Allow-by-exception
1.00
IA-2(5)Individual Authentication with Group Authentication
1.00
SC-2Separation of System and User Functionality
1.00
SC-23Session Authenticity
1.00

+3 more (top 10 by confidence shown)

CCI2 mappings
CCI-001749
1.00
CCI-003992
1.00

Details

Check Text (C-257799r1106273_chk)

Verify RHEL 9 is configured to disable kernel image loading. Check the status of the kernel.kexec_load_disabled kernel parameter. $ sudo sysctl kernel.kexec_load_disabled kernel.kexec_load_disabled = 1 If "kernel.kexec_load_disabled" is not set to "1" or is missing, this is a finding. Check that the configuration files are present to enable this kernel parameter. $ sudo grep -r kernel.kexec_load_disabled /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf /etc/sysctl.d/99-sysctl.conf:kernel.kexec_load_disabled = 1 If "kernel.kexec_load_disabled" is not set to "1", is missing, or commented out, this is a finding. If conflicting results are returned, this is a finding.

Fix Text (F-61464r1106272_fix)

Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: kernel.kexec_load_disabled = 1 Remove any configurations that conflict with the above from the following locations: /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf /lib/sysctl.d/*.conf /etc/sysctl.conf /etc/sysctl.d/*.conf Load settings from all system configuration files with the following command: $ sudo sysctl --system