Title

RHEL 9 must enable mitigations against processor-based vulnerabilities. (Cat III impact)

Discussion

Kernel page-table isolation is a kernel feature that mitigates the Meltdown security vulnerability and hardens the kernel against attempts to bypass kernel address space layout randomization (KASLR). Satisfies: SRG-OS-000433-GPOS-00193, SRG-OS-000095-GPOS-00049

Check Content

Verify RHEL 9 enables kernel page-table isolation with the following command: $ sudo grubby --info=ALL | grep pti args="ro crashkernel=auto resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap rhgb quiet fips=1 audit=1 audit_backlog_limit=8192 pti=on If the "pti" entry does not equal "on", or is missing, this is a finding. Check that kernel page-table isolation is enabled by default to persist in kernel updates: $ sudo grep pti /etc/default/grub GRUB_CMDLINE_LINUX="pti=on" If "pti" is not set to "on", is missing or commented out, this is a finding.

Fix Text

Configure RHEL 9 to enable kernel page-table isolation with the following command: $ sudo grubby --update-kernel=ALL --args="pti=on" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="pti=on"

Additional Identifiers

Rule ID: SV-257795r925372_rule

Vulnerability ID: V-257795

Group Title: SRG-OS-000433-GPOS-00193

Expert Comments

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