STIGQter STIGQter: STIG Summary: Cloud Linux AlmaLinux OS 9 Security Technical Implementation Guide Version: 1 Release: 7 Benchmark Date: 01 Jul 2026:

AlmaLinux OS 9 must clear the page allocator to prevent use-after-free attacks.

DISA Rule

SV-269293r1050175_rule

Vulnerability Number

V-269293

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

ALMA-09-024110

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Configure AlmaLinux OS 9 to enable page poisoning with the following commands:

$ grubby --update-kernel=ALL --args="page_poison=1"

Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates:

GRUB_CMDLINE_LINUX="page_poison=1"

Check Contents

Verify that GRUB 2 is configured to enable page poisoning to mitigate use-after-free vulnerabilities.

Check that the current GRUB 2 configuration has page poisoning enabled with the following command:

$ grubby --info=ALL | grep args | grep -v 'page_poison=1'

If any output is returned, this is a finding.

Check that page poisoning is enabled by default to persist in kernel updates with the following command:

$ grep page_poison /etc/default/grub

GRUB_CMDLINE_LINUX="page_poison=1"

If "page_poison" is not set to "1", is missing or commented out, this is a finding.

Vulnerability Number

V-269293

Documentable

False

Rule Version

ALMA-09-024110

Severity Override Guidance

Verify that GRUB 2 is configured to enable page poisoning to mitigate use-after-free vulnerabilities.

Check that the current GRUB 2 configuration has page poisoning enabled with the following command:

$ grubby --info=ALL | grep args | grep -v 'page_poison=1'

If any output is returned, this is a finding.

Check that page poisoning is enabled by default to persist in kernel updates with the following command:

$ grep page_poison /etc/default/grub

GRUB_CMDLINE_LINUX="page_poison=1"

If "page_poison" is not set to "1", is missing or commented out, this is a finding.

Check Content Reference

M

Target Key

5664