CVE-2026-64181 mm: fix __vm_normal_page() to handle missing support for pmd_special()/pud_special()

In the Linux kernel, the following vulnerability has been resolved: mm: fix vmnormalpage to handle missing support for pmdspecial/pudspecial On x86 32-bit with THP enabled, zaphugepmd is seen to generate a "WARNING: mm/memory.c:735 at vmnormalpage+0x6a/0x7d", from the VMWARNONONCEiszeropfnpfn ||...