CVE-2026-80685: mm/util: don't read __page_2 for order-1 folios in snapshot_page()

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-28 · updated 2026-09-21

Description

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).

Affected products

Linux kernel: from 6.12.111 before 6.13; 6.15 — fixed in 6.13, 7.2

How to fix

Upgrade to a fixed version: Linux kernel 6.13, 7.2. Check the vendor advisory for mitigations.

References

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