CVE-2025-37890 (GCVE-0-2025-37890)
Vulnerability from cvelistv5 – Published: 2025-05-16 13:01 – Updated: 2026-08-05 11:58
VLAI
EPSS
VEX
Title
net_sched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc
Summary
In the Linux kernel, the following vulnerability has been resolved:
net_sched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc
As described in Gerrard's report [1], we have a UAF case when an hfsc class
has a netem child qdisc. The crux of the issue is that hfsc is assuming
that checking for cl->qdisc->q.qlen == 0 guarantees that it hasn't inserted
the class in the vttree or eltree (which is not true for the netem
duplicate case).
This patch checks the n_active class variable to make sure that the code
won't insert the class in the vttree or eltree twice, catering for the
reentrant case.
[1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/
Severity
7.8 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-10 20:42 UTC
Assigner
References
10 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea , < 273bbcfa53541cde38b2003ad88a59b770306421
(git)
Affected: 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea , < e0cf8ee23e1915431f262a7b2dee0c7a7d699af0 (git) Affected: 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea , < e3e949a39a91d1f829a4890e7dfe9417ac72e4d0 (git) Affected: 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea , < 8df7d37d626430035b413b97cee18396b3450bef (git) Affected: 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea , < 6082a87af4c52f58150d40dec1716011d871ac21 (git) Affected: 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea , < 2e7093c7a8aba5d4f8809f271488e5babe75e202 (git) Affected: 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea , < ac39fd4a757584d78ed062d4f6fd913f83bd98b5 (git) Affected: 37d9cf1a3ce35de3df6f7d209bfb1f50cf188cea , < 141d34391abbb315d68556b7c67ad97885407547 (git) |
guessed | |
| Linux | Linux |
Affected:
5.0
Unaffected: 0 , < 5.0 (semver) Unaffected: 5.4.294 , ≤ 5.4.* (semver) Unaffected: 5.10.238 , ≤ 5.10.* (semver) Unaffected: 5.15.182 , ≤ 5.15.* (semver) Unaffected: 6.1.138 , ≤ 6.1.* (semver) Unaffected: 6.6.90 , ≤ 6.6.* (semver) Unaffected: 6.12.28 , ≤ 6.12.* (semver) Unaffected: 6.14.6 , ≤ 6.14.* (semver) Unaffected: 6.15 , ≤ * (original_commit_for_fix) |
guessed |
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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