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Full vulnerability report · 2024
CVE-2021-47587High confidence

net: systemport: Add global locking for descriptor lifecycle

Linux · Linux

9.8CriticalCVSS 3.1
Recommended action
Within 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

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-2021-34589

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 actionWithin 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
01

What, why and how

In the Linux kernel, the following vulnerability has been resolved: net: systemport: Add global locking for descriptor lifecycle The descriptor list is a shared resource across all of the transmit queues, and the locking mechanism used today only protects concurrency across a given transmit queue between the transmit and reclaiming. This creates an opportunity for the SYSTEMPORT hardware to work on corrupted descriptors if we have multiple producers at once which is the case when using multiple transmit queues. This was particularly noticeable when using multiple flows/transmit queues and it showed up in interesting ways in that UDP packets would get a correct UDP header checksum being calculated over an incorrect packet length. Similarly TCP packets would get an equally correct checksum computed by the hardware over an incorrect packet length. The SYSTEMPORT hardware maintains an internal descriptor list that it re-arranges when the driver produces a new descriptor anytime it writes to the WRITE_PORT_{HI,LO} registers, there is however some delay in the hardware to re-organize its descriptors and it is possible that concurrent TX queues eventually break this internal allocation scheme to the point where the length/status part of the descriptor gets used for an incorrect data buffer. The fix is to impose a global serialization for all TX queues in the short section where we are writing to the WRITE_PORT_{HI,LO} registers which solves the corruption even with multiple concurrent TX queues being used.

What

In the Linux kernel, the following vulnerability has been resolved: net: systemport: Add global locking for descriptor lifecycle The descriptor list is a shared resource across all of the transmit queues, and the locking mechanism used today only protects concurrency across a given transmit queue between the transmit and reclaiming. This creates an opportunity for the SYSTEMPORT hardware to work on corrupted descriptors if we have multiple producers at once which is the case when using multiple transmit queues. This was particularly noticeable when using multiple flows/transmit queues and it showed up in interesting ways in that UDP packets would get a correct UDP header checksum being calculated over an incorrect packet length. Similarly TCP packets would get an equally correct checksum computed by the hardware over an incorrect packet length. The SYSTEMPORT hardware maintains an internal descriptor list that it re-arranges when the driver produces a new descriptor anytime it writes to the WRITE_PORT_{HI,LO} registers, there is however some delay in the hardware to re-organize its descriptors and it is possible that concurrent TX queues eventually break this internal allocation scheme to the point where the length/status part of the descriptor gets used for an incorrect data buffer. The fix is to impose a global serialization for all TX queues in the short section where we are writing to the WRITE_PORT_{HI,LO} registers which solves the corruption even with multiple concurrent TX queues being used.

Why

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. 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: net: systemport: Add global locking for descriptor lifecycle The descriptor list is a shared resource across all of the transmit queues, and the locking mechanism used today only protects concurrency across a given transmit queue between the transmit and reclaiming. This creates an opportunity for the SYSTEMPORT hardware to work on corrupted descriptors if we have multiple producers at once which is the case when using multiple transmit queues. This was particularly noticeable when using multiple flows/transmit queues and it showed up in interesting ways in that UDP packets would get a correct UDP header checksum being calculated over an incorrect packet length. Similarly TCP packets would get an equally correct checksum computed by the hardware over an incorrect packet length. The SYSTEMPORT hardware maintains an internal descriptor list that it re-arranges when the driver produces a new descriptor anytime it writes to the WRITE_PORT_{HI,LO} registers, there is however some delay in the hardware to re-organize its descriptors and it is possible that concurrent TX queues eventually break this internal allocation scheme to the point where the length/status part of the descriptor gets used for an incorrect data buffer. The fix is to impose a global serialization for all TX queues in the short section where we are writing to the WRITE_PORT_{HI,LO} registers which solves the corruption even with multiple concurrent TX queues being used.

Why

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. 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
a network path → Improper Locking → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
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-667

CWE-667: Improper Locking. The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

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

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

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-667
A

Official authority intelligence

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

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-2024-AVI-0693Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2021-47576 Référence CVE CVE-2021-47577 https://www.cve.org/CVERecord?id=CVE-2021-47577 Référence CVE CVE-2021-47578 https://www.cve.org/CVERecord?id=CVE-2021-47578 Référence CVE CVE-2021-47580 https://www.cve.org/CVERecord?id=CVE-2021-47580 Référence CVE CVE-2021-47582 https://www.cve.org/CVERecord?id=CVE-2021-47582 Référence CVE CVE-2021-47583 https://www.cve.org/CVERecord?id=CVE-2021-47583 Référence CVE CVE-2021-47584 https://www.cve.org/CVERecord?id=CVE-2021-47584 Référence CVE CVE-2021-47585 https://www.cve.org/CVERecord?id=CVE-2021-47585 Référence CVE CVE-2021-47586 https://www.cve.org/CVERecord?id=CVE-2021-47586 Référence CVE CVE-2021-47587 https://www.cve.org/CVERecord?id=CVE-2021-47587 Référence CVE CVE-2021-47588 https://www.cve.org/CVERecord?id=CVE-2021-47588 Référence CVE CVE-2021-47589 https://www.cve.org/CVERecord?id=CVE-2021-47589 Référence CVE CVE-2021-47590 https://www.cve.org/CVERecord?id=CVE-2021-47590 Référence CVE CVE-2021-47591 https://www.cve.org/CVERecord?id=CVE-2021-47591 Référence CVE CVE-2021-47592 https://www.cve.org/CVERecord?id=CVE-2021-47592 Référence CVE CVE-2021-47593 https://www.cve.org/CVERecord?id=CVE-2021-47593 Référence CVE CVE-2021-47595 https://www.cve.org/CVERecord?id=CVE-2021-47595 Référence CVE CVE-2021-47596 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0610Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2021-47498 Référence CVE CVE-2021-47518 https://www.cve.org/CVERecord?id=CVE-2021-47518 Référence CVE CVE-2021-47520 https://www.cve.org/CVERecord?id=CVE-2021-47520 Référence CVE CVE-2021-47544 https://www.cve.org/CVERecord?id=CVE-2021-47544 Référence CVE CVE-2021-47547 https://www.cve.org/CVERecord?id=CVE-2021-47547 Référence CVE CVE-2021-47555 https://www.cve.org/CVERecord?id=CVE-2021-47555 Référence CVE CVE-2021-47566 https://www.cve.org/CVERecord?id=CVE-2021-47566 Référence CVE CVE-2021-47571 https://www.cve.org/CVERecord?id=CVE-2021-47571 Référence CVE CVE-2021-47576 https://www.cve.org/CVERecord?id=CVE-2021-47576 Référence CVE CVE-2021-47587 https://www.cve.org/CVERecord?id=CVE-2021-47587 Référence CVE CVE-2021-47589 https://www.cve.org/CVERecord?id=CVE-2021-47589 Référence CVE CVE-2021-47600 https://www.cve.org/CVERecord?id=CVE-2021-47600 Référence CVE CVE-2021-47602 https://www.cve.org/CVERecord?id=CVE-2021-47602 Référence CVE CVE-2021-47603 https://www.cve.org/CVERecord?id=CVE-2021-47603 Référence CVE CVE-2021-47609 https://www.cve.org/CVERecord?id=CVE-2021-47609 Référence CVE CVE-2021-47617 https://www.cve.org/CVERecord?id=CVE-2021-47617 Référence CVE CVE-2022-0435 https://www.cve.org/CVERecord?id=CVE-2022-0435 Référence CVE CVE-2022-22942 https://www.cve.org/CVERecord?id=CV

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0578Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2021-47576 Référence CVE CVE-2021-47577 https://www.cve.org/CVERecord?id=CVE-2021-47577 Référence CVE CVE-2021-47578 https://www.cve.org/CVERecord?id=CVE-2021-47578 Référence CVE CVE-2021-47580 https://www.cve.org/CVERecord?id=CVE-2021-47580 Référence CVE CVE-2021-47582 https://www.cve.org/CVERecord?id=CVE-2021-47582 Référence CVE CVE-2021-47583 https://www.cve.org/CVERecord?id=CVE-2021-47583 Référence CVE CVE-2021-47584 https://www.cve.org/CVERecord?id=CVE-2021-47584 Référence CVE CVE-2021-47585 https://www.cve.org/CVERecord?id=CVE-2021-47585 Référence CVE CVE-2021-47586 https://www.cve.org/CVERecord?id=CVE-2021-47586 Référence CVE CVE-2021-47587 https://www.cve.org/CVERecord?id=CVE-2021-47587 Référence CVE CVE-2021-47589 https://www.cve.org/CVERecord?id=CVE-2021-47589 Référence CVE CVE-2021-47592 https://www.cve.org/CVERecord?id=CVE-2021-47592 Référence CVE CVE-2021-47595 https://www.cve.org/CVERecord?id=CVE-2021-47595 Référence CVE CVE-2021-47596 https://www.cve.org/CVERecord?id=CVE-2021-47596 Référence CVE CVE-2021-47597 https://www.cve.org/CVERecord?id=CVE-2021-47597 Référence CVE CVE-2021-47600 https://www.cve.org/CVERecord?id=CVE-2021-47600 Référence CVE CVE-2021-47601 https://www.cve.org/CVERecord?id=CVE-2021-47601 Référence CVE CVE-2021-47602 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-021315Linux の Linux Kernel におけるリソースのロックに関する脆弱性

Linux の Linux Kernel には、リソースのロックに関する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: 80105befdb4b8cea924711b40b2462b87df65b62 < 8ed2f5d08d6e59f8c78b2869bfb95d0be32c094c, 80105befdb4b8cea924711b40b2462b87df65b62 < de57f62f76450b934de8203711bdc4f7953c3421, 80105befdb4b8cea924711b40b2462b87df65b62 < f3fde37d3f0d429f0fcce214cb52588a9e21260e, 80105befdb4b8cea924711b40b2462b87df65b62 < 595a684fa6f23b21958379a18cfa83862c73c2e1, 80105befdb4b8cea924711b40b2462b87df65b62 < c675256a7f131f5ba3f331efb715e8f31ea0e392, 80105befdb4b8cea924711b40b2462b87df65b62 < 6e1011cd183faae8daff275c72444edcdfe0d473, 80105befdb4b8cea924711b40b2462b87df65b62 < eb4687c7442942e115420a30185f8d83faf37696, 80105befdb4b8cea924711b40b2462b87df65b62 < 8b8e6e782456f1ce02a7ae914bbd5b1053f0b034, 3.16
Fixed
Linux: < 3.16, 4.4.296 ≤ 4.4.*, 4.9.294 ≤ 4.9.*, 4.14.259 ≤ 4.14.*, 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. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 19 Jun 2024 · Last source change 5 Aug 2026, 08:48 UTC · CWE-667 · Improper Locking

CVE recordCVE.org · 5.2
CVSS sourceCNA
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-2021-34589
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment

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-2021-47587 · cve.blacktree.nl