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

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/zip/U_RHEL_9_V2R3_STIG.zip

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION, SYSTEM AND INFORMATION INTEGRITY

References: 800-53|SC-2, 800-53|SI-16, CAT|II, CCI|CCI-001082, CCI|CCI-002824, Rule-ID|SV-257800r1044851_rule, STIG-ID|RHEL-09-213025, Vuln-ID|V-257800

Plugin: Unix

Control ID: eb9c3e358da2b51ce23eb7a587e010c344d15545d410638614a5cf499df42114