CVE-2026-80685
Description
AI Translation Available
In the Linux kernel, the following vulnerability has been resolved:
mm/util: don't read __page_2 for order-1 folios in snapshot_page()
snapshot_page() currently reads __page_2 after checking nr_pages > 1, but
it should only do so when nr_pages > 2.
If an order-1 folio is allocated at the end of a vmemmap section,
__page_2 will not exist and reading it will cause a fault.
During DLPAR memory remove on a 22 TB ppc64le LPAR, snapshot_page() oopsed
on the page isolation path while reading an order-1 folio's __page_2 from
an adjacent absent section (unmapped vmemmap).
Fix this to avoid reading memmap that doesn't exist (e.g., a vmemmap
hole).
https://git.kernel.org/stable/c/7441d6348c70738e9ed307510db171c7a9b3f4bf
https://git.kernel.org/stable/c/9668ffe0e2a5e2399dce281620198a2e415871fc
https://git.kernel.org/stable/c/c649324571206a30949765320b91ccdb4c1722dc