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Full vulnerability report · 2025
CVE-2025-39725High confidence

mm/vmscan: fix hwpoisoned large folio handling in shrink_folio_list

Linux · Linux

5.5MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

13 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivelinux-aws-6.14Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azure-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azure-fde-6.14Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-azure-nvidia-6.14Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-gcp-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-hwe-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-intelAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-lowlatency-hwe-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-oem-6.14Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-oracle-6.14Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-raspi-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-riscvAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 10 Sept 2026
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2025-33997

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

In the Linux kernel, the following vulnerability has been resolved: mm/vmscan: fix hwpoisoned large folio handling in shrink_folio_list In shrink_folio_list(), the hwpoisoned folio may be large folio, which can't be handled by unmap_poisoned_folio(). For THP, try_to_unmap_one() must be passed with TTU_SPLIT_HUGE_PMD to split huge PMD first and then retry. Without TTU_SPLIT_HUGE_PMD, we will trigger null-ptr deref of pvmw.pte. Even we passed TTU_SPLIT_HUGE_PMD, we will trigger a WARN_ON_ONCE due to the page isn't in swapcache. Since UCE is rare in real world, and race with reclaimation is more rare, just skipping the hwpoisoned large folio is enough. memory_failure() will handle it if the UCE is triggered again. This happens when memory reclaim for large folio races with memory_failure(), and will lead to kernel panic. The race is as follows: cpu0 cpu1 shrink_folio_list memory_failure TestSetPageHWPoison unmap_poisoned_folio --> trigger BUG_ON due to unmap_poisoned_folio couldn't handle large folio [tujinjiang@huawei.com: add comment to unmap_poisoned_folio()]

What

In the Linux kernel, the following vulnerability has been resolved: mm/vmscan: fix hwpoisoned large folio handling in shrink_folio_list In shrink_folio_list(), the hwpoisoned folio may be large folio, which can't be handled by unmap_poisoned_folio(). For THP, try_to_unmap_one() must be passed with TTU_SPLIT_HUGE_PMD to split huge PMD first and then retry. Without TTU_SPLIT_HUGE_PMD, we will trigger null-ptr deref of pvmw.pte. Even we passed TTU_SPLIT_HUGE_PMD, we will trigger a WARN_ON_ONCE due to the page isn't in swapcache. Since UCE is rare in real world, and race with reclaimation is more rare, just skipping the hwpoisoned large folio is enough. memory_failure() will handle it if the UCE is triggered again. This happens when memory reclaim for large folio races with memory_failure(), and will lead to kernel panic. The race is as follows: cpu0 cpu1 shrink_folio_list memory_failure TestSetPageHWPoison unmap_poisoned_folio --> trigger BUG_ON due to unmap_poisoned_folio couldn't handle large folio [tujinjiang@huawei.com: add comment to unmap_poisoned_folio()]

Why

The product dereferences a pointer that it expects to be valid but is NULL.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

In the Linux kernel, the following vulnerability has been resolved: mm/vmscan: fix hwpoisoned large folio handling in shrink_folio_list In shrink_folio_list(), the hwpoisoned folio may be large folio, which can't be handled by unmap_poisoned_folio(). For THP, try_to_unmap_one() must be passed with TTU_SPLIT_HUGE_PMD to split huge PMD first and then retry. Without TTU_SPLIT_HUGE_PMD, we will trigger null-ptr deref of pvmw.pte. Even we passed TTU_SPLIT_HUGE_PMD, we will trigger a WARN_ON_ONCE due to the page isn't in swapcache. Since UCE is rare in real world, and race with reclaimation is more rare, just skipping the hwpoisoned large folio is enough. memory_failure() will handle it if the UCE is triggered again. This happens when memory reclaim for large folio races with memory_failure(), and will lead to kernel panic. The race is as follows: cpu0 cpu1 shrink_folio_list memory_failure TestSetPageHWPoison unmap_poisoned_folio --> trigger BUG_ON due to unmap_poisoned_folio couldn't handle large folio [tujinjiang@huawei.com: add comment to unmap_poisoned_folio()]

Why

The product dereferences a pointer that it expects to be valid but is NULL.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → NULL Pointer Dereference → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-476

CWE-476: NULL Pointer Dereference. The product dereferences a pointer that it expects to be valid but is NULL.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
CWE-476
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-W-2025-1988Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen oder nicht näher spezifizierte Auswirkungen zu erzielen.

Official advisory
CERT-FR · French · CERTFR-2025-AVI-1135Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2025-39693 Référence CVE CVE-2025-39697 https://www.cve.org/CVERecord?id=CVE-2025-39697 Référence CVE CVE-2025-39702 https://www.cve.org/CVERecord?id=CVE-2025-39702 Référence CVE CVE-2025-39703 https://www.cve.org/CVERecord?id=CVE-2025-39703 Référence CVE CVE-2025-39709 https://www.cve.org/CVERecord?id=CVE-2025-39709 Référence CVE CVE-2025-39710 https://www.cve.org/CVERecord?id=CVE-2025-39710 Référence CVE CVE-2025-39713 https://www.cve.org/CVERecord?id=CVE-2025-39713 Référence CVE CVE-2025-39714 https://www.cve.org/CVERecord?id=CVE-2025-39714 Référence CVE CVE-2025-39724 https://www.cve.org/CVERecord?id=CVE-2025-39724 Référence CVE CVE-2025-39725 https://www.cve.org/CVERecord?id=CVE-2025-39725 Référence CVE CVE-2025-39726 https://www.cve.org/CVERecord?id=CVE-2025-39726 Référence CVE CVE-2025-39727 https://www.cve.org/CVERecord?id=CVE-2025-39727 Référence CVE CVE-2025-39728 https://www.cve.org/CVERecord?id=CVE-2025-39728 Référence CVE CVE-2025-39730 https://www.cve.org/CVERecord?id=CVE-2025-39730 Référence CVE CVE-2025-39731 https://www.cve.org/CVERecord?id=CVE-2025-39731 Référence CVE CVE-2025-39732 https://www.cve.org/CVERecord?id=CVE-2025-39732 Référence CVE CVE-2025-39734 https://www.cve.org/CVERecord?id=CVE-2025-39734 Référence CVE CVE-2025-39735 https://www.cve.org/CVERecord?id=

Official advisory
CERT-FR · French · CERTFR-2025-AVI-1075Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2025-39693 Référence CVE CVE-2025-39697 https://www.cve.org/CVERecord?id=CVE-2025-39697 Référence CVE CVE-2025-39702 https://www.cve.org/CVERecord?id=CVE-2025-39702 Référence CVE CVE-2025-39703 https://www.cve.org/CVERecord?id=CVE-2025-39703 Référence CVE CVE-2025-39709 https://www.cve.org/CVERecord?id=CVE-2025-39709 Référence CVE CVE-2025-39710 https://www.cve.org/CVERecord?id=CVE-2025-39710 Référence CVE CVE-2025-39713 https://www.cve.org/CVERecord?id=CVE-2025-39713 Référence CVE CVE-2025-39714 https://www.cve.org/CVERecord?id=CVE-2025-39714 Référence CVE CVE-2025-39724 https://www.cve.org/CVERecord?id=CVE-2025-39724 Référence CVE CVE-2025-39725 https://www.cve.org/CVERecord?id=CVE-2025-39725 Référence CVE CVE-2025-39726 https://www.cve.org/CVERecord?id=CVE-2025-39726 Référence CVE CVE-2025-39727 https://www.cve.org/CVERecord?id=CVE-2025-39727 Référence CVE CVE-2025-39730 https://www.cve.org/CVERecord?id=CVE-2025-39730 Référence CVE CVE-2025-39731 https://www.cve.org/CVERecord?id=CVE-2025-39731 Référence CVE CVE-2025-39732 https://www.cve.org/CVERecord?id=CVE-2025-39732 Référence CVE CVE-2025-39734 https://www.cve.org/CVERecord?id=CVE-2025-39734 Référence CVE CVE-2025-39736 https://www.cve.org/CVERecord?id=CVE-2025-39736 Référence CVE CVE-2025-39737 https://www.cve.org/CVERecord?id=

Official advisory
CERT-FR · French · CERTFR-2025-AVI-1050Multiples vulnérabilités dans le noyau Linux d'Ubuntu

d?id=CVE-2025-38664 Référence CVE CVE-2025-38665 https://www.cve.org/CVERecord?id=CVE-2025-38665 Référence CVE CVE-2025-38666 https://www.cve.org/CVERecord?id=CVE-2025-38666 Référence CVE CVE-2025-38668 https://www.cve.org/CVERecord?id=CVE-2025-38668 Référence CVE CVE-2025-38670 https://www.cve.org/CVERecord?id=CVE-2025-38670 Référence CVE CVE-2025-38671 https://www.cve.org/CVERecord?id=CVE-2025-38671 Référence CVE CVE-2025-38675 https://www.cve.org/CVERecord?id=CVE-2025-38675 Référence CVE CVE-2025-38678 https://www.cve.org/CVERecord?id=CVE-2025-38678 Référence CVE CVE-2025-39682 https://www.cve.org/CVERecord?id=CVE-2025-39682 Référence CVE CVE-2025-39725 https://www.cve.org/CVERecord?id=CVE-2025-39725 Référence CVE CVE-2025-39726 https://www.cve.org/CVERecord?id=CVE-2025-39726 Référence CVE CVE-2025-39727 https://www.cve.org/CVERecord?id=CVE-2025-39727 Référence CVE CVE-2025-39728 https://www.cve.org/CVERecord?id=CVE-2025-39728 Référence CVE CVE-2025-39730 https://www.cve.org/CVERecord?id=CVE-2025-39730 Référence CVE CVE-2025-39731 https://www.cve.org/CVERecord?id=CVE-2025-39731 Référence CVE CVE-2025-39732 https://www.cve.org/CVERecord?id=CVE-2025-39732 Référence CVE CVE-2025-39734 https://www.cve.org/CVERecord?id=CVE-2025-39734 Référence CVE CVE-2025-39735 https://www.cve.org/CVERecord?id=

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
1c9798bf8145a92abf45aa9d38a6406d9eb8bdf0 < 656eaddbc952e1baae2f69281c22debe22140312; 1b0449544c6482179ac84530b61fc192a6527bfd < c1101113d45838a823188ae25c61af97552a28ae; 1b0449544c6482179ac84530b61fc192a6527bfd < 9f1e8cd0b7c4c944e9921b52a6661b5eda2705ab; 912e9f0300c3564b72a8808db406e313193a37ad; 6.12.26 < 6.12.41; 6.14.5 < 6.15; 6.15
Fixed
< 6.15; 6.12.41 ≤ 6.12.*; 6.15.9 ≤ 6.15.*; 6.16 ≤ *
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 5 Sept 2025 · Last source change 23 May 2026, 16:00 UTC · CWE-476 · NULL Pointer Dereference

CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2025-33997
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2025-39725 · cve.blacktree.nl