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Full vulnerability report · 2024
CVE-2021-47579High confidence

ovl: fix warning in ovl_create_real()

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.

1 package state
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-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 11 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-2021-34581

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: ovl: fix warning in ovl_create_real() Syzbot triggered the following warning in ovl_workdir_create() -> ovl_create_real(): if (!err && WARN_ON(!newdentry->d_inode)) { The reason is that the cgroup2 filesystem returns from mkdir without instantiating the new dentry. Weird filesystems such as this will be rejected by overlayfs at a later stage during setup, but to prevent such a warning, call ovl_mkdir_real() directly from ovl_workdir_create() and reject this case early.

What

In the Linux kernel, the following vulnerability has been resolved: ovl: fix warning in ovl_create_real() Syzbot triggered the following warning in ovl_workdir_create() -> ovl_create_real(): if (!err && WARN_ON(!newdentry->d_inode)) { The reason is that the cgroup2 filesystem returns from mkdir without instantiating the new dentry. Weird filesystems such as this will be rejected by overlayfs at a later stage during setup, but to prevent such a warning, call ovl_mkdir_real() directly from ovl_workdir_create() and reject this case early.

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

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: ovl: fix warning in ovl_create_real() Syzbot triggered the following warning in ovl_workdir_create() -> ovl_create_real(): if (!err && WARN_ON(!newdentry->d_inode)) { The reason is that the cgroup2 filesystem returns from mkdir without instantiating the new dentry. Weird filesystems such as this will be rejected by overlayfs at a later stage during setup, but to prevent such a warning, call ovl_mkdir_real() directly from ovl_workdir_create() and reject this case early.

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

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 → vulnerable operation → 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.
CWE not yet assigned
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.
A

Official authority intelligence

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

BSI · German · WID-SEC-2024-1913Red Hat OpenShift Container Platform: Mehrere Schwachstellen

Ein entfernter anonymer oder lokaler Angreifer kann mehrere Schwachstellen in Red Hat OpenShift Container Platform ausnutzen, um seine Privilegien zu erhöhen, beliebigen Code auszuführen, einen Denial-of-Service-Zustand zu erzeugen, vertrauliche Informationen offenzulegen, Dateien und Daten zu manipulieren oder Sicherheitsmaßnahmen zu umgehen.

Official advisory ↗
BSI · German · WID-SEC-2024-1418Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff

Ein lokaler Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20240626Security Bulletin 26 Jun 2024

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 26 Jun 2024, published on 26 June 2024. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-1165Multiples vulnérabilités dans les produits IBM

d?id=CVE-2021-47461 Référence CVE CVE-2021-47466 https://www.cve.org/CVERecord?id=CVE-2021-47466 Référence CVE CVE-2021-47468 https://www.cve.org/CVERecord?id=CVE-2021-47468 Référence CVE CVE-2021-47491 https://www.cve.org/CVERecord?id=CVE-2021-47491 Référence CVE CVE-2021-47495 https://www.cve.org/CVERecord?id=CVE-2021-47495 Référence CVE CVE-2021-47497 https://www.cve.org/CVERecord?id=CVE-2021-47497 Référence CVE CVE-2021-47527 https://www.cve.org/CVERecord?id=CVE-2021-47527 Référence CVE CVE-2021-47548 https://www.cve.org/CVERecord?id=CVE-2021-47548 Référence CVE CVE-2021-47560 https://www.cve.org/CVERecord?id=CVE-2021-47560 Référence CVE CVE-2021-47579 https://www.cve.org/CVERecord?id=CVE-2021-47579 Référence CVE CVE-2021-47582 https://www.cve.org/CVERecord?id=CVE-2021-47582 Référence CVE CVE-2021-47609 https://www.cve.org/CVERecord?id=CVE-2021-47609 Référence CVE CVE-2021-47624 https://www.cve.org/CVERecord?id=CVE-2021-47624 Référence CVE CVE-2022-2047 https://www.cve.org/CVERecord?id=CVE-2022-2047 Référence CVE CVE-2022-24785 https://www.cve.org/CVERecord?id=CVE-2022-24785 Référence CVE CVE-2022-24823 https://www.cve.org/CVERecord?id=CVE-2022-24823 Référence CVE CVE-2022-25168 https://www.cve.org/CVERecord?id=CVE-2022-25168 Référence CVE CVE-2022-25647 https://www.cve.org/CVERecord?id=CV

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-1057Multiples vulnérabilités dans les produits VMware

d?id=CVE-2021-47537 Référence CVE CVE-2021-47538 https://www.cve.org/CVERecord?id=CVE-2021-47538 Référence CVE CVE-2021-47539 https://www.cve.org/CVERecord?id=CVE-2021-47539 Référence CVE CVE-2021-47550 https://www.cve.org/CVERecord?id=CVE-2021-47550 Référence CVE CVE-2021-47559 https://www.cve.org/CVERecord?id=CVE-2021-47559 Référence CVE CVE-2021-47561 https://www.cve.org/CVERecord?id=CVE-2021-47561 Référence CVE CVE-2021-47572 https://www.cve.org/CVERecord?id=CVE-2021-47572 Référence CVE CVE-2021-47576 https://www.cve.org/CVERecord?id=CVE-2021-47576 Référence CVE CVE-2021-47578 https://www.cve.org/CVERecord?id=CVE-2021-47578 Référence CVE CVE-2021-47579 https://www.cve.org/CVERecord?id=CVE-2021-47579 Référence CVE CVE-2021-47601 https://www.cve.org/CVERecord?id=CVE-2021-47601 Référence CVE CVE-2021-47607 https://www.cve.org/CVERecord?id=CVE-2021-47607 Référence CVE CVE-2021-47609 https://www.cve.org/CVERecord?id=CVE-2021-47609 Référence CVE CVE-2021-47613 https://www.cve.org/CVERecord?id=CVE-2021-47613 Référence CVE CVE-2021-47616 https://www.cve.org/CVERecord?id=CVE-2021-47616 Référence CVE CVE-2021-47617 https://www.cve.org/CVERecord?id=CVE-2021-47617 Référence CVE CVE-2021-47620 https://www.cve.org/CVERecord?id=CVE-2021-47620 Référence CVE CVE-2021-47623 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-0072Multiples vulnérabilités dans Juniper Secure Analytics

d?id=CVE-2021-47257 Référence CVE CVE-2021-47284 https://www.cve.org/CVERecord?id=CVE-2021-47284 Référence CVE CVE-2021-47304 https://www.cve.org/CVERecord?id=CVE-2021-47304 Référence CVE CVE-2021-47373 https://www.cve.org/CVERecord?id=CVE-2021-47373 Référence CVE CVE-2021-47408 https://www.cve.org/CVERecord?id=CVE-2021-47408 Référence CVE CVE-2021-47461 https://www.cve.org/CVERecord?id=CVE-2021-47461 Référence CVE CVE-2021-47468 https://www.cve.org/CVERecord?id=CVE-2021-47468 Référence CVE CVE-2021-47491 https://www.cve.org/CVERecord?id=CVE-2021-47491 Référence CVE CVE-2021-47548 https://www.cve.org/CVERecord?id=CVE-2021-47548 Référence CVE CVE-2021-47579 https://www.cve.org/CVERecord?id=CVE-2021-47579 Référence CVE CVE-2021-47624 https://www.cve.org/CVERecord?id=CVE-2021-47624 Référence CVE CVE-2022-48632 https://www.cve.org/CVERecord?id=CVE-2022-48632 Référence CVE CVE-2022-48743 https://www.cve.org/CVERecord?id=CVE-2022-48743 Référence CVE CVE-2022-48747 https://www.cve.org/CVERecord?id=CVE-2022-48747 Référence CVE CVE-2022-48757 https://www.cve.org/CVERecord?id=CVE-2022-48757 Référence CVE CVE-2023-28746 https://www.cve.org/CVERecord?id=CVE-2023-28746 Référence CVE CVE-2023-4692 https://www.cve.org/CVERecord?id=CVE-2023-4692 Référence CVE CVE-2023-4693 https://www.cve.org/CVERecord?id=CVE

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0958Multiples vulnérabilités dans les produits IBM

d?id=CVE-2021-47284 Référence CVE CVE-2021-47304 https://www.cve.org/CVERecord?id=CVE-2021-47304 Référence CVE CVE-2021-47373 https://www.cve.org/CVERecord?id=CVE-2021-47373 Référence CVE CVE-2021-47408 https://www.cve.org/CVERecord?id=CVE-2021-47408 Référence CVE CVE-2021-47449 https://www.cve.org/CVERecord?id=CVE-2021-47449 Référence CVE CVE-2021-47461 https://www.cve.org/CVERecord?id=CVE-2021-47461 Référence CVE CVE-2021-47468 https://www.cve.org/CVERecord?id=CVE-2021-47468 Référence CVE CVE-2021-47491 https://www.cve.org/CVERecord?id=CVE-2021-47491 Référence CVE CVE-2021-47548 https://www.cve.org/CVERecord?id=CVE-2021-47548 Référence CVE CVE-2021-47579 https://www.cve.org/CVERecord?id=CVE-2021-47579 Référence CVE CVE-2021-47624 https://www.cve.org/CVERecord?id=CVE-2021-47624 Référence CVE CVE-2022-23181 https://www.cve.org/CVERecord?id=CVE-2022-23181 Référence CVE CVE-2022-23471 https://www.cve.org/CVERecord?id=CVE-2022-23471 Référence CVE CVE-2022-23648 https://www.cve.org/CVERecord?id=CVE-2022-23648 Référence CVE CVE-2022-24999 https://www.cve.org/CVERecord?id=CVE-2022-24999 Référence CVE CVE-2022-25762 https://www.cve.org/CVERecord?id=CVE-2022-25762 Référence CVE CVE-2022-29885 https://www.cve.org/CVERecord?id=CVE-2022-29885 Référence CVE CVE-2022-31030 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0668Multiples vulnérabilités dans le noyau Linux de Red Hat

d?id=CVE-2021-47284 Référence CVE CVE-2021-47304 https://www.cve.org/CVERecord?id=CVE-2021-47304 Référence CVE CVE-2021-47373 https://www.cve.org/CVERecord?id=CVE-2021-47373 Référence CVE CVE-2021-47393 https://www.cve.org/CVERecord?id=CVE-2021-47393 Référence CVE CVE-2021-47408 https://www.cve.org/CVERecord?id=CVE-2021-47408 Référence CVE CVE-2021-47461 https://www.cve.org/CVERecord?id=CVE-2021-47461 Référence CVE CVE-2021-47468 https://www.cve.org/CVERecord?id=CVE-2021-47468 Référence CVE CVE-2021-47491 https://www.cve.org/CVERecord?id=CVE-2021-47491 Référence CVE CVE-2021-47548 https://www.cve.org/CVERecord?id=CVE-2021-47548 Référence CVE CVE-2021-47579 https://www.cve.org/CVERecord?id=CVE-2021-47579 Référence CVE CVE-2021-47624 https://www.cve.org/CVERecord?id=CVE-2021-47624 Référence CVE CVE-2022-48632 https://www.cve.org/CVERecord?id=CVE-2022-48632 Référence CVE CVE-2022-48637 https://www.cve.org/CVERecord?id=CVE-2022-48637 Référence CVE CVE-2022-48743 https://www.cve.org/CVERecord?id=CVE-2022-48743 Référence CVE CVE-2022-48747 https://www.cve.org/CVERecord?id=CVE-2022-48747 Référence CVE CVE-2022-48757 https://www.cve.org/CVERecord?id=CVE-2022-48757 Référence CVE CVE-2023-28746 https://www.cve.org/CVERecord?id=CVE-2023-28746 Référence CVE CVE-2023-52451 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-022033Linux の Linux Kernel における脆弱性

Linux の Linux Kernel には、不特定の脆弱性が存在します。

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
Linux: e9be9d5e76e34872f0c37d72e25bc27fe9e2c54c < 445d2dc63e5871d218f21b8f62ab29ac72f2e6b8, e9be9d5e76e34872f0c37d72e25bc27fe9e2c54c < f9f300a92297be8250547347fd52216ef0177ae0, e9be9d5e76e34872f0c37d72e25bc27fe9e2c54c < 6859985a2fbda5d1586bf44538853e1be69e85f7, e9be9d5e76e34872f0c37d72e25bc27fe9e2c54c < d2ccdd4e4efab06178608a34d7bfb20a54104c02, e9be9d5e76e34872f0c37d72e25bc27fe9e2c54c < 1f5573cfe7a7056e80a92c7a037a3e69f3a13d1c, 3.18
Fixed
Linux: < 3.18, 4.19.222 ≤ 4.19.*, 5.4.168 ≤ 5.4.*, 5.10.88 ≤ 5.10.*, 5.15.11 ≤ 5.15.*, 5.16 ≤ *
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 19 Jun 2024 · Last source change 11 May 2026, 13:57 UTC · CWE not yet assigned

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-2021-34581
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceUnavailable
NVD statusNVD enriched

Missing structured fields: CWE classification. Missing data is not evidence of low risk; review the primary advisory.

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-2021-47579 · cve.blacktree.nl