Kernel memory leak via uncleared devlink parent pointer
Published Dec 4, 2025 · Updated Aug 5, 2026
Improper reference-count handling in Linux and RUGGEDCOM RST2428P builds allows local users to consume unreclaimed kernel memory. devl_rate_nodes_destroy calls the driver parent-set operation and decrements the parent refcount but fails to clear devlink_rate->parent, leaving a dangling pointer that is decremented again during rate-object destruction. Triggering the demonstrated netdevsim or mlx5 paths requires local low-privileged access and configured devlink rate objects; the resulting refcount error leaks memory and can interrupt service.
Summary
What happened
Improper reference-count handling in Linux and RUGGEDCOM RST2428P builds allows local users to consume unreclaimed kernel memory. devl_rate_nodes_destroy calls the driver parent-set operation and decrements the parent refcount but fails to clear devlink_rate->parent, leaving a dangling pointer that is decremented again during rate-object destruction. Triggering the demonstrated netdevsim or mlx5 paths requires local low-privileged access and configured devlink rate objects; the resulting refcount error leaks memory and can interrupt service.
The record
- CVE
- CVE-2025-40251
- Published
- Dec 4, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-911, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 4, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=5.14
- Affected versionversion=d7555984507822458b32a6405881038241d140be <542f45486f1ce2d2dde75bd85aca0389ef7046c3
- Affected versionversion=d7555984507822458b32a6405881038241d140be <715d9cda646a8a38ea8b2bb5afb679a7464055e2
- Affected versionversion=d7555984507822458b32a6405881038241d140be <90e51e20bcec9bff5b2421ce1bd95704764655f5
- Affected versionversion=d7555984507822458b32a6405881038241d140be <c70df6c17d389cc743f0eb30160e2d6bc6910db8
- Affected versionversion=d7555984507822458b32a6405881038241d140be <f94c1a114ac209977bdf5ca841b98424295ab1f0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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