CVE-2026-89755

Received Received - Intake

Linux kernel Memory Corruption in mm/migrate_device

Publication date: 2026-09-11

Last updated on: 2026-09-11

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: mm/migrate_device: clear stale mapping after freeing swapcache __migrate_device_pages() reads the folio mapping before calling folio_free_swap(). When folio_free_swap() succeeds, the folio is removed from the swap cache, but the saved mapping still points to swap_space. Passing the stale mapping to folio_migrate_mapping() makes it use the mapped-folio path for a folio that is no longer in swapcache. It can then operate on swap_space.i_pages with invalid reference accounting, eventually triggering a folio reference count BUG. After a successful split, nr still contains the number of pages in the original large folio, although each resulting page is now a separate order-0 folio. Reset nr to 1 so each split folio is processed separately, including its own swapcache removal and mapping lookup. Refresh the saved mapping after folio_free_swap() so the current folio state is used during migration.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-11

Last Modified

2026-09-11

Generated

2026-09-12

AI Q&A

2026-09-12

EPSS Evaluated

N/A

NVD

CVE-2026-89755

EUVD

EUVD-2026-76667

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a flaw in memory page migration where stale mapping references cause incorrect folio state handling. When migrating device pages, the system fails to update mapping references after freeing swap cache, leading to invalid folio reference accounting and potential reference count bugs.

Detection Guidance

This vulnerability is specific to the Linux kernel's memory management subsystem and does not have direct network detection methods. Detection requires checking kernel versions and examining system logs for related errors. Use commands like 'uname -a' to check kernel version and 'dmesg | grep -i migrate' to look for related errors.

Impact Analysis

This vulnerability could cause system instability or crashes due to incorrect memory management. It may lead to kernel panics or unexpected behavior when handling memory operations, potentially affecting system reliability and performance.

Mitigation Strategies

Apply the latest kernel updates from your Linux distribution to patch this vulnerability. If immediate patching is not possible, consider isolating affected systems or limiting memory-intensive operations until updates are applied.

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