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NVD / CVE Program· CNA Linux

CVE-2025-21694: fs/proc: fix softlockup in __read_vmcore (part 2)

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: 0.24% (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 4.20, 5.10.234, 5.15.177; azl3 kernel 6.6.64.2-9 on Azure Linux 3.0 6.6.76.1-1; azl3 kernel 6.6.76.1-1 on Azure Linux 3.0 6.6.76.1-1.

Low priority for now. Upgrade to Linux Linux 4.20, 5.10.234, 5.15.177; azl3 kernel 6.6.64.2-9 on Azure Linux 3.0 6.6.76.1-1; azl3 kernel 6.6.76.1-1 on Azure Linux 3.0 6.6.76.1-1 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: fs/proc: fix softlockup in __read_vmcore (part 2) Since commit 5cbcb62dddf5 ("fs/proc: fix softlockup in __read_vmcore") the number of softlockups in __read_vmcore at kdump time have gone down, but they still happen sometimes. In a memory constrained environment like the kdump image, a softlockup is not just a harmless message, but it can interfere with things like RCU freeing memory, causing the crashdump to get stuck. The second loop in __read_vmcore has a lot more opportunities for natural sleep points, like scheduling out while waiting for a data write to happen, but apparently that is not always enough. Add a cond_resched() to the second loop in __read_vmcore to (hopefully) get rid of the softlockups.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Feb 12, 2025
Updated
Oct 15, 2026
EPSS
0.2% · 15th percentile
CWE
—

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 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.5
CNA · Linux
5.5
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • 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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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 kernel4.19.317 and later · before 4.20
  • linux linux kernel5.4.279 and later · before 5.4.290
  • linux linux kernel5.10.221 and later · before 5.10.234
  • linux linux kernel5.15.162 and later · before 5.15.177
  • linux linux kernel6.1.95 and later · before 6.1.127
  • linux linux kernel6.6.35 and later · before 6.6.74
  • linux linux kernel6.9.6 and later · before 6.12.11
  • linux linux kernel6.13

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

    • 7bdf1d550ddfcd9ab797087421f77b7aceddc8a7, e8780e8a0e25dc4c3927f611ec8970d26c0c7369, 6.10affected
    • 803d5a33d5ffdc2d86dcc0cfa01655a330612cdb and later · before 84c4ed15626574c9ac6c1039ba9c137a77bcc7f2affected · git
    • 70c1835e776c8447c1aca87ddb38cfe764fe756a and later · before 80da29deb88a3a907441fc35bb7bac309f31e713affected · git
    • e1b160a50c756e0efbea290b9bf5117cb80e8c4b and later · before 649b266606bc413407ce315f710c8ce8a88ee30aaffected · git
    • a373ad833a6bfe4bc6cedcf7e56a99cc6fd9a193 and later · before 65c367bd9d4f43513c7f837df5753bea9561b836affected · git
    • 518fbd644dabb6aedbdd4939c6c9cc1bf651459f and later · before a5a2ee8144c3897d37403a69118c3e3dc5713958affected · git
    • 5cbcb62dddf5346077feb82b7b0c9254222d3445 and later · before 80828540dad0757b6337c6561d49c81038f38d87affected · git
    • 5cbcb62dddf5346077feb82b7b0c9254222d3445 and later · before cbc5dde0a461240046e8a41c43d7c3b76d5db952affected · git
    • 5.4.279 and later · before 5.4.290affected · semver
    • 5.10.221 and later · before 5.10.234affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.128-16.1.128-1
Debian:13linuxbefore 6.12.11-16.12.11-1

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-2025-21699Feb 12, 2025 · gfs2: Truncate address space when flipping GFS2_DIF_JDATA flag
    22Monitor
  • ← EarlierCVE-2024-57951Feb 12, 2025 · hrtimers: Handle CPU state correctly on hotplug
    31Monitor
  • Later →CVE-2025-21696Feb 12, 2025 · mm: clear uffd-wp PTE/PMD state on mremap()
    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 Linux4.20Vendor (CNA)
Linux Linux5.10.234Vendor (CNA)
Linux Linux5.15.177Vendor (CNA)
Linux Linux5.4.290Vendor (CNA)
Linux Linux6.1.127Vendor (CNA)
Linux Linux6.10Vendor (CNA)
Linux Linux6.6.74Vendor (CNA)
Linux Linux649b266606bc413407ce315f710c8ce8a88ee30aVendor (CNA)
Linux Linux65c367bd9d4f43513c7f837df5753bea9561b836Vendor (CNA)
Linux Linux80828540dad0757b6337c6561d49c81038f38d87Vendor (CNA)
Linux Linux80da29deb88a3a907441fc35bb7bac309f31e713Vendor (CNA)
Linux Linux84c4ed15626574c9ac6c1039ba9c137a77bcc7f2Vendor (CNA)
Linux Linuxa5a2ee8144c3897d37403a69118c3e3dc5713958Vendor (CNA)
Linux Linuxcbc5dde0a461240046e8a41c43d7c3b76d5db952Vendor (CNA)
azl3 kernel 6.6.64.2-9 on Azure Linux 3.06.6.76.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.76.1-1 on Azure Linux 3.06.6.76.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.176.3-3 on CBL Mariner 2.05.15.180.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.176.3-3 on CBL-Mariner 2.05.15.180.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.180.1-1 on CBL Mariner 2.05.15.180.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.128-1 · 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)

—

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. Fix✗ → ✓

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

References

Show all references (11 more)

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

All records