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Response snapshot Nov 6, 2026, 19:41 UTC

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VulnerabilityCVE-2026-89755

Linux kernel: mm/migrate_device: clear stale mapping after freeing swapcache

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().

At a glance

Exploited
Not known
Severity
7.8 High (CVSS 3.1)
Chance of exploitation
0.2% in the next 30 days
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-89755 (opens a new tab)

What happened

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.

Continue reading

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.

Scores and how they were measured

CVSS base severity

7.8

Version 3.1As of

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.2%

Scored Percentile 4.9%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-89755 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  4. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-89755, scored 2026-11-06. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, November 6). Linux kernel: mm/migrate_device: clear stale mapping after freeing swapcache (CVE-2026-89755). https://kevwire.com/record/CVE-2026-89755

MLA

"Linux kernel: mm/migrate_device: clear stale mapping after freeing swapcache (CVE-2026-89755)." KEVWire, 6 Nov. 2026, kevwire.com/record/CVE-2026-89755.

Chicago

KEVWire. "Linux kernel: mm/migrate_device: clear stale mapping after freeing swapcache (CVE-2026-89755)." Last modified November 6, 2026. https://kevwire.com/record/CVE-2026-89755.

Evidence summary (plain text)

Linux kernel: mm/migrate_device: clear stale mapping after freeing swapcache (Sep 11, 2026).
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.
CVSS 7.8 (version 3.1; evidence as of Nov 6, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-89755).
EPSS 0.2% for the following 30 days, scored Nov 6, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-89755&date=2026-11-06).
Sources:
NVD CVE-2026-89755: https://nvd.nist.gov/vuln/detail/CVE-2026-89755
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-06T17:36:35.718Z&lastModEndDate=2026-11-06T19:20:58.655Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-06T17:06:05.906Z&lastModEndDate=2026-11-06T18:35:59.598Z&resultsPerPage=500&startIndex=500
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-89755&date=2026-11-06
Record ID: CVE-2026-89755.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Nov 6, 2026, 19:36 UTC. Ingestion is not an independent editorial investigation.

NVD status: Received. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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Record details

Record detail