TOSS 5 must restrict exposed kernel pointer addresses access.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-282507 | SRG-OS-000132-GPOS-00067 | TOSS-05-000101 | SV-282507r1200501_rule | 2026-04-01 | 1 |
Description
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-000433-GPOS-00193
ℹ️ Check
Verify the runtime status of the "kernel.kptr_restrict" kernel parameter using the following command:
$ sudo sysctl kernel.kptr_restrict
kernel.kptr_restrict = 1
If "kernel.kptr_restrict" is not set to "1" or is missing, this is a finding.
✔️ Fix
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 using the following command:
$ sudo sysctl --system