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EUVD-2026-344351

European Vulnerability Database identifier assigned by ENISA

Reserved

2026-10-02 07:56

Assigner

ENISA

Alias of

a CVE record, shown under related vulnerabilities. This identifier carries no description, severity or references of its own: they belong to that CVE.

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{
  "assigner": "ENISA",
  "date_reserved": "2026-10-02T07:56:04.438597+00:00",
  "id": "EUVD-2026-344351"
}

CVE-2021-46989 (GCVE-0-2021-46989)

Vulnerability from cvelistv5 – Published: 2024-02-28 08:13 – Updated: 2026-08-05 08:45

Title

hfsplus: prevent corruption in shrinking truncate

Summary

In the Linux kernel, the following vulnerability has been resolved: hfsplus: prevent corruption in shrinking truncate I believe there are some issues introduced by commit 31651c607151 ("hfsplus: avoid deadlock on file truncation") HFS+ has extent records which always contains 8 extents. In case the first extent record in catalog file gets full, new ones are allocated from extents overflow file. In case shrinking truncate happens to middle of an extent record which locates in extents overflow file, the logic in hfsplus_file_truncate() was changed so that call to hfs_brec_remove() is not guarded any more. Right action would be just freeing the extents that exceed the new size inside extent record by calling hfsplus_free_extents(), and then check if the whole extent record should be removed. However since the guard (blk_cnt > start) is now after the call to hfs_brec_remove(), this has unfortunate effect that the last matching extent record is removed unconditionally. To reproduce this issue, create a file which has at least 10 extents, and then perform shrinking truncate into middle of the last extent record, so that the number of remaining extents is not under or divisible by 8. This causes the last extent record (8 extents) to be removed totally instead of truncating into middle of it. Thus this causes corruption, and lost data. Fix for this is simply checking if the new truncated end is below the start of this extent record, making it safe to remove the full extent record. However call to hfs_brec_remove() can't be moved to it's previous place since we're dropping ->tree_lock and it can cause a race condition and the cached info being invalidated possibly corrupting the node data. Another issue is related to this one. When entering into the block (blk_cnt > start) we are not holding the ->tree_lock. We break out from the loop not holding the lock, but hfs_find_exit() does unlock it. Not sure if it's possible for someone else to take the lock under our feet, but it can cause hard to debug errors and premature unlocking. Even if there's no real risk of it, the locking should still always be kept in balance. Thus taking the lock now just before the check.

Severity

7.1 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

5.5 (Medium)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-02-28 18:24 UTC

CWE

CWE-noinfo Not enough information

Assigner

Linux mitre root Scorecard

References

6 references

URL	Tags
https://git.kernel.org/stable/c/52dde855663e5db82…
https://git.kernel.org/stable/c/c451a6bafb5f42219…
https://git.kernel.org/stable/c/adbd8a2a8cc05d9e5…
https://git.kernel.org/stable/c/c477f62db1a0c0eca…
https://git.kernel.org/stable/c/97314e45aa1223a42…
https://git.kernel.org/stable/c/c3187cf32216313fb…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 31651c607151f1034cfb57e5a78678bea54c362b , < 52dde855663e5db824af51db39b5757d2ef3e28a (git) Affected: 31651c607151f1034cfb57e5a78678bea54c362b , < c451a6bafb5f422197d31536f82116aed132b72c (git) Affected: 31651c607151f1034cfb57e5a78678bea54c362b , < adbd8a2a8cc05d9e501f93e5c95c59307874cc99 (git) Affected: 31651c607151f1034cfb57e5a78678bea54c362b , < c477f62db1a0c0ecaa60a29713006ceeeb04b685 (git) Affected: 31651c607151f1034cfb57e5a78678bea54c362b , < 97314e45aa1223a42d60256a62c5d9af54baf446 (git) Affected: 31651c607151f1034cfb57e5a78678bea54c362b , < c3187cf32216313fb316084efac4dab3a8459b1d (git)
Linux	Linux	Affected: 4.19 Unaffected: 0 , < 4.19 (semver) Unaffected: 4.19.191 , ≤ 4.19.* (semver) Unaffected: 5.4.120 , ≤ 5.4.* (semver) Unaffected: 5.10.38 , ≤ 5.10.* (semver) Unaffected: 5.11.22 , ≤ 5.11.* (semver) Unaffected: 5.12.5 , ≤ 5.12.* (semver) Unaffected: 5.13 , ≤ * (original_commit_for_fix)

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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.

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.
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EUVD-2026-344351

CVE-2021-46989 (GCVE-0-2021-46989)

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