CVE-2026-46139 (GCVE-0-2026-46139)
Vulnerability from cvelistv5 – Published: 2026-05-28 09:35 – Updated: 2026-06-14 17:57
VLAI
EPSS
VEX
Title
smb: client: use kzalloc to zero-initialize security descriptor buffer
Summary
In the Linux kernel, the following vulnerability has been resolved:
smb: client: use kzalloc to zero-initialize security descriptor buffer
Commit 62e7dd0a39c2d ("smb: common: change the data type of num_aces
to le16") split struct smb_acl's __le32 num_aces field into __le16
num_aces and __le16 reserved. The reserved field corresponds to Sbz2
in the MS-DTYP ACL wire format, which must be zero [1].
When building an ACL descriptor in build_sec_desc(), we are using a
kmalloc()'ed descriptor buffer and writing the fields explicitly using
le16() writes now. This never writes to the 2 byte reserved field,
leaving it as uninitialized heap data.
When the reserved field happens to contain non-zero slab garbage,
Samba rejects the security descriptor with "ndr_pull_security_descriptor
failed: Range Error", causing chmod to fail with EINVAL.
Change kmalloc() to kzalloc() to ensure the entire buffer is
zero-initialized.
[1] https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-dtyp/20233ed8-a6c6-4097-aafa-dd545ed24428
Severity
5.5 (Medium)
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
1593ddb37bd124c131fe635397df68e854a03108 , < 4c3ed344a970aad51388ac3b0145b98318f0e21f
(git)
Affected: da087905e3270e2291c0afae39a28e7d183e5ec3 , < 941a1e6eb35440336913afc88a82103291956d5d (git) Affected: 62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d , < be1ef9512a3f5a755895c24f31b334342f4aa15b (git) Affected: 62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d , < 9bdb2ca31368b7671949dfb94a5d57ffccd01edd (git) Affected: 62e7dd0a39c2d0d7ff03274c36df971f1b3d2d0d , < 5e489c6c47a2ac15edbaca153b9348e42c1eacab (git) Affected: 191f2f444745087c3c51fd6042a0e25f42315ab0 (git) Affected: 6.12.23 , < 6.12.88 (semver) Affected: 6.13.11 , < 6.14 (semver) |
guessed | |
| Linux | Linux |
Affected:
6.14
Unaffected: 0 , < 6.14 (semver) Unaffected: 6.12.88 , ≤ 6.12.* (semver) Unaffected: 6.18.30 , ≤ 6.18.* (semver) Unaffected: 7.0.7 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (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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