CVE-2026-31398 mm/rmap: fix incorrect pte restoration for lazyfree folios

In the Linux kernel, the following vulnerability has been resolved: mm/rmap: fix incorrect pte restoration for lazyfree folios We batch unmap anonymous lazyfree folios by foliounmapptebatch. If the batch has a mix of writable and non-writable bits, we may end up setting the entire batch writable...