RHEL-09-213025 - RHEL 9 must restrict exposed kernel pointer addresses access.

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Information

Exposing kernel pointers (through procfs or 'seq_printf()') exposes kernel writeable structures, which may contain functions pointers. If a write vulnerability occurs in the kernel, allowing write access to any of this structure, the kernel can be compromised. This option disallows any program without the CAP_SYSLOG capability to get the addresses of kernel pointers by replacing them with '0'.

Satisfies: SRG-OS-000132-GPOS-00067, SRG-OS-000433-GPOS-00192, SRG-OS-000480-GPOS-00227

Solution

Add or edit the following line in a system configuration file in the '/etc/sysctl.d/' directory:

kernel.kptr_restrict = 1

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

$ sudo sysctl --system

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/U_RHEL_9_V1R1_STIG.zip

Item Details

References: CAT|II, CCI|CCI-000366, CCI|CCI-001082, CCI|CCI-002824, Rule-ID|SV-257800r925387_rule, STIG-ID|RHEL-09-213025, Vuln-ID|V-257800

Plugin: Unix

Control ID: ab1d125a2542e432d06eaf4f821028922e7fe86d512122a24eb71458a6bfd76e