CVE-2026-64130

/// Technical description

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

mm/page_alloc: fix initialization of tags of the huge zero folio with init_on_free

__GFP_ZEROTAGS semantics are currently a bit weird, but effectively this

flag is only ever set alongside __GFP_ZERO and __GFP_SKIP_KASAN.

If we run with init_on_free, we will zero out pages during

__free_pages_prepare(), to skip zeroing on the allocation path.

However, when allocating with __GFP_ZEROTAG set, post_alloc_hook() will

consequently not only skip clearing page content, but also skip clearing

tag memory.

Not clearing tags through __GFP_ZEROTAGS is irrelevant for most pages that

will get mapped to user space through set_pte_at() later: set_pte_at() and

friends will detect that the tags have not been initialized yet

(PG_mte_tagged not set), and initialize them.

However, for the huge zero folio, which will be mapped through a PMD

marked as special, this initialization will not be performed, ending up

exposing whatever tags w

/// 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