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NVD / CVE Program· CNA Linux

CVE-2025-23131: dlm: prevent NPD when writing a positive value to event_done

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.19% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 10b7a59814765d18d43555c9cef4eb3048b7e8a3, 7109d69bec6edce546dc870e66bd2b668a3d5549, 8e2bad543eca5c25cd02cbc63d72557934d45f13; azl3 kernel 6.6.143.1-1 on Azure Linux 3.0 6.6.144.1-1.

Low priority for now. Upgrade to Linux Linux 10b7a59814765d18d43555c9cef4eb3048b7e8a3, 7109d69bec6edce546dc870e66bd2b668a3d5549, 8e2bad543eca5c25cd02cbc63d72557934d45f13; azl3 kernel 6.6.143.1-1 on Azure Linux 3.0 6.6.144.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: dlm: prevent NPD when writing a positive value to event_done do_uevent returns the value written to event_done. In case it is a positive value, new_lockspace would undo all the work, and lockspace would not be set. __dlm_new_lockspace, however, would treat that positive value as a success due to commit 8511a2728ab8 ("dlm: fix use count with multiple joins"). Down the line, device_create_lockspace would pass that NULL lockspace to dlm_find_lockspace_local, leading to a NULL pointer dereference. Treating such positive values as successes prevents the problem. Given this has been broken for so long, this is unlikely to break userspace expectations.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Apr 16, 2025
Updated
Nov 5, 2026
EPSS
0.1% · 9th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel2.6.31 and later · before 6.14.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2.6.31affected
    • 8511a2728ab82cab398e39d019f5cf1246021c1c and later · before a1c41aebb184d9228a440dcb6761224e65b0e49aaffected · git
    • 8511a2728ab82cab398e39d019f5cf1246021c1c and later · before ee28d99d789b077565cbe0377374d1e826c64d93affected · git
    • 8511a2728ab82cab398e39d019f5cf1246021c1c and later · before c7837e2c96559663c33f43da403d9cf3cf77cfa7affected · git
    • 8511a2728ab82cab398e39d019f5cf1246021c1c and later · before 7109d69bec6edce546dc870e66bd2b668a3d5549affected · git
    • 8511a2728ab82cab398e39d019f5cf1246021c1c and later · before 10b7a59814765d18d43555c9cef4eb3048b7e8a3affected · git
    • 8511a2728ab82cab398e39d019f5cf1246021c1c and later · before b73c4ad4d387fe5bc988145bd9f1bc0de76afd5caffected · git
    • 8511a2728ab82cab398e39d019f5cf1246021c1c and later · before 8e2bad543eca5c25cd02cbc63d72557934d45f13affected · git
    • before 2.6.31not affected · semver
    • 5.10.260 and later · up to and including 5.10.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.177-16.1.177-1
Debian:13linuxbefore 6.12.95-16.12.95-1
Debian:14linuxbefore 6.16.3-16.16.3-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2025-22127Apr 16, 2025 · f2fs: fix potential deadloop in prepare_compress_overwrite()
    22Monitor
  • ← EarlierCVE-2025-22128Apr 16, 2025 · wifi: ath12k: Clear affinity hint before calling ath12k_pci_free_irq() in error path
    22Monitor
  • Later →CVE-2025-23132Apr 16, 2025 · f2fs: quota: fix to avoid warning in dquot_writeback_dquots()
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux10b7a59814765d18d43555c9cef4eb3048b7e8a3Vendor (CNA)
Linux Linux7109d69bec6edce546dc870e66bd2b668a3d5549Vendor (CNA)
Linux Linux8e2bad543eca5c25cd02cbc63d72557934d45f13Vendor (CNA)
Linux Linuxa1c41aebb184d9228a440dcb6761224e65b0e49aVendor (CNA)
Linux Linuxb73c4ad4d387fe5bc988145bd9f1bc0de76afd5cVendor (CNA)
Linux Linuxc7837e2c96559663c33f43da403d9cf3cf77cfa7Vendor (CNA)
Linux Linuxee28d99d789b077565cbe0377374d1e826c64d93Vendor (CNA)
azl3 kernel 6.6.143.1-1 on Azure Linux 3.06.6.144.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0—Microsoft (MSRC)
debian:linux6.1.177-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records