STIGQter: STIG Summary: Red Hat Enterprise Linux 9 Security Technical Implementation Guide Version: 2 Release: 9 Benchmark Date: 01 Jul 2026:

RHEL 9 must enable kernel parameters to enforce discretionary access control (DAC) on hardlinks.

DISA Rule

SV-257801r1155703_rule

Vulnerability Number

V-257801

Group Title

SRG-OS-000312-GPOS-00123

Rule Version

RHEL-09-213030

Severity

CAT II

CCI(s)

• CCI-002165 - Enforce organization-defined discretionary access control policies over defined subjects and objects.
• CCI-002235 - Prevent non-privileged users from executing privileged functions.

Weight

10

Fix Recommendation

Configure RHEL 9 to enable DAC on hardlinks.

Create a drop-in if it does not already exist:

$ sudo vi /etc/sysctl.d/99-fs_protected_hardlinks.conf

Add the following to the file:
fs.protected_hardlinks = 1

Reload settings from all system configuration files with the following command:

$ sudo sysctl --system

Check Contents

Verify RHEL 9 is configured to enable DAC on hardlinks.

Check the status of the "fs.protected_hardlinks" kernel parameter with the following command:

$ sudo sysctl fs.protected_hardlinks
fs.protected_hardlinks = 1

If "fs.protected_hardlinks" is not set to "1" or is missing, this is a finding.

Vulnerability Number

V-257801

Documentable

False

Rule Version

RHEL-09-213030

Severity Override Guidance

Verify RHEL 9 is configured to enable DAC on hardlinks.

Check the status of the "fs.protected_hardlinks" kernel parameter with the following command:

$ sudo sysctl fs.protected_hardlinks
fs.protected_hardlinks = 1

If "fs.protected_hardlinks" is not set to "1" or is missing, this is a finding.

Check Content Reference

M

Target Key

5551