CVE-2026-97525

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

x86/mm/pat: Allocate split page tables as kernel page tables

A PTE is allocated directly without going through the standard page table

allocation routines (such as pte_alloc_one_kernel()) when the CPA code

splits a large page (__split_large_page()).

This means the page table constructor is never called nor is the page table

marked as a kernel page table.

The former results in the folio associated with the page table not being

marked as a page table (__pagetable_ctor() is never called thus neither is

__folio_set_pgtable()) nor are statistics updated to reflect

it (lruvec_stat_add_folio() is never called).

The latter issue of failing to mark the page table as a kernel page

table (ptdesc_set_kernel() is never called) is far more problematic.

Since commit:

5ba2f0a15564 ("mm: introduce deferred freeing for kernel page tables")

kernel page table freeing has been batched and since the

subsequent commit:

e37d5a2d6

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References