CVE-2025-40353

A flaw was found in the Linux kernel’s arm64 copy_highpage() implementation related to Memory Tagging Extensionflag handling. The function previously assumed that a destination page for a copy operation would always be newly allocated and untagged. Under certain memory migration paths, this assumption no longer holds, and copy_highpage() could generate extraneous WARN_ON_ONCE() messages if the page was already MTE-tagged.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.