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CVE Record

CVE-2025-21975: net/mlx5: handle errors in mlx5_chains_create_table()

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: handle errors in mlx5_chains_create_table() In mlx5_chains_create_table(), the return value of mlx5_get_fdb_sub_ns() and mlx5_get_flow_namespace() must be checked to prevent NULL pointer dereferences. If either function fails, the function should log error message with mlx5_core_warn() and return error pointer.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2025-21975 is a Linux kernel flaw in mlx5 networking code where missing error checks can lead to a NULL pointer dereference. The public record does not provide CVSS, CWE, impact severity, or confirmed exploit activity. Treat this as a kernel reliability and availability concern until vendor guidance clarifies risk.

Executive priority

Handle through normal kernel patch governance unless mlx5-dependent systems support critical network paths. The business urgency is currently constrained by missing severity data and no cited exploitation evidence, but kernel NULL dereferences can still affect availability.

Technical view

In net/mlx5, mlx5_chains_create_table() did not validate return values from mlx5_get_fdb_sub_ns() and mlx5_get_flow_namespace(). The resolved behavior checks for failures, logs with mlx5_core_warn(), and returns an error pointer instead of dereferencing NULL.

Likely exposure

Exposure appears limited to Linux systems running affected kernel versions or branches containing the vulnerable mlx5 code. The bundle does not name specific distributions, hardware models, configurations, or remote attack conditions. Debian LTS advisories are referenced, indicating downstream Linux package attention.

Exploitation context

The CVE is not marked KEV, and the provided sources do not claim active exploitation or public exploit availability. The source bundle describes a NULL pointer dereference prevention fix, but does not explain attacker reachability, required privileges, or trigger path.

Researcher notes

Key unknowns are triggerability, privilege boundary, and whether the vulnerable path is reachable through local configuration or network-driven behavior. Analysis should focus on mlx5_chains_create_table() callers and failure paths without assuming exploitability beyond the public description.

Mitigation direction

  • Check your Linux distribution's advisory and kernel package status for CVE-2025-21975.
  • Update to a vendor-supported kernel that includes the referenced stable fixes.
  • Prioritize systems using mlx5 networking functionality in production or high-availability roles.
  • Track Debian LTS updates if operating affected Debian long-term support systems.

Validation and detection

  • Inventory Linux kernel versions across servers and appliances.
  • Identify systems loading or depending on net/mlx5 functionality.
  • Compare installed kernels against vendor fixed package advisories.
  • Confirm change management records show the updated kernel is booted, not only installed.
Prepared
Confidence
medium
Sources
11

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

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CVE-2025-21975 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
1ADP providers
10Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux39ac237ce00968545e7298faa9e07ecb7e440fb5, 39ac237ce00968545e7298faa9e07ecb7e440fb5, 39ac237ce00968545e7298faa9e07ecb7e440fb5, 39ac237ce00968545e7298faa9e07ecb7e440fb5, 39ac237ce00968545e7298faa9e07ecb7e440fb5, 39ac237ce00968545e7298faa9e07ecb7e440fb5, 39ac237ce00968545e7298faa9e07ecb7e440fb5unaffected
LinuxLinux5.6, 0, 5.10.236, 5.15.180, 6.1.132, 6.6.84, 6.12.20, 6.13.8, 6.14affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.