FKIE_CVE-2025-40233
Vulnerability from fkie_nvd - Published: 2025-12-04 16:16 - Updated: 2026-07-30 06:24
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: clear extent cache after moving/defragmenting extents
The extent map cache can become stale when extents are moved or
defragmented, causing subsequent operations to see outdated extent flags.
This triggers a BUG_ON in ocfs2_refcount_cal_cow_clusters().
The problem occurs when:
1. copy_file_range() creates a reflinked extent with OCFS2_EXT_REFCOUNTED
2. ioctl(FITRIM) triggers ocfs2_move_extents()
3. __ocfs2_move_extents_range() reads and caches the extent (flags=0x2)
4. ocfs2_move_extent()/ocfs2_defrag_extent() calls __ocfs2_move_extent()
which clears OCFS2_EXT_REFCOUNTED flag on disk (flags=0x0)
5. The extent map cache is not invalidated after the move
6. Later write() operations read stale cached flags (0x2) but disk has
updated flags (0x0), causing a mismatch
7. BUG_ON(!(rec->e_flags & OCFS2_EXT_REFCOUNTED)) triggers
Fix by clearing the extent map cache after each extent move/defrag
operation in __ocfs2_move_extents_range(). This ensures subsequent
operations read fresh extent data from disk.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/ocfs2/move_extents.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "93166bc53c0e3587058327a4121daea34b4fecd5",
"status": "affected",
"version": "53069d4e76954e2e63c1b3c501051c6fbcf7298c",
"versionType": "git"
},
{
"lessThan": "a7ee72286efba1d407c6f15a0528e43593fb7007",
"status": "affected",
"version": "53069d4e76954e2e63c1b3c501051c6fbcf7298c",
"versionType": "git"
},
{
"lessThan": "93b1ab422f1966b71561158e1aedce4ec100f357",
"status": "affected",
"version": "53069d4e76954e2e63c1b3c501051c6fbcf7298c",
"versionType": "git"
},
{
"lessThan": "e92af7737a94a729225d2a5d180eaaa77fe0bbc1",
"status": "affected",
"version": "53069d4e76954e2e63c1b3c501051c6fbcf7298c",
"versionType": "git"
},
{
"lessThan": "aa6a21409dd6221bb268b56bb410e031c632ff9a",
"status": "affected",
"version": "53069d4e76954e2e63c1b3c501051c6fbcf7298c",
"versionType": "git"
},
{
"lessThan": "bb69928ed578f881e68d26aaf1a8f6e7faab3b44",
"status": "affected",
"version": "53069d4e76954e2e63c1b3c501051c6fbcf7298c",
"versionType": "git"
},
{
"lessThan": "a21750df2f6169af6e039a3bb4893d6c9564e48d",
"status": "affected",
"version": "53069d4e76954e2e63c1b3c501051c6fbcf7298c",
"versionType": "git"
},
{
"lessThan": "78a63493f8e352296dbc7cb7b3f4973105e8679e",
"status": "affected",
"version": "53069d4e76954e2e63c1b3c501051c6fbcf7298c",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/ocfs2/move_extents.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.0"
},
{
"lessThan": "3.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"version": "5.4.301",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.246",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.196",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.158",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.115",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.56",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.17.*",
"status": "unaffected",
"version": "6.17.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.18",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: clear extent cache after moving/defragmenting extents\n\nThe extent map cache can become stale when extents are moved or\ndefragmented, causing subsequent operations to see outdated extent flags. \nThis triggers a BUG_ON in ocfs2_refcount_cal_cow_clusters().\n\nThe problem occurs when:\n1. copy_file_range() creates a reflinked extent with OCFS2_EXT_REFCOUNTED\n2. ioctl(FITRIM) triggers ocfs2_move_extents()\n3. __ocfs2_move_extents_range() reads and caches the extent (flags=0x2)\n4. ocfs2_move_extent()/ocfs2_defrag_extent() calls __ocfs2_move_extent()\n which clears OCFS2_EXT_REFCOUNTED flag on disk (flags=0x0)\n5. The extent map cache is not invalidated after the move\n6. Later write() operations read stale cached flags (0x2) but disk has\n updated flags (0x0), causing a mismatch\n7. BUG_ON(!(rec-\u003ee_flags \u0026 OCFS2_EXT_REFCOUNTED)) triggers\n\nFix by clearing the extent map cache after each extent move/defrag\noperation in __ocfs2_move_extents_range(). This ensures subsequent\noperations read fresh extent data from disk."
}
],
"id": "CVE-2025-40233",
"lastModified": "2026-07-30T06:24:18.947",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2025-12-04T16:16:16.137",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/78a63493f8e352296dbc7cb7b3f4973105e8679e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/93166bc53c0e3587058327a4121daea34b4fecd5"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/93b1ab422f1966b71561158e1aedce4ec100f357"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a21750df2f6169af6e039a3bb4893d6c9564e48d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a7ee72286efba1d407c6f15a0528e43593fb7007"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/aa6a21409dd6221bb268b56bb410e031c632ff9a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/bb69928ed578f881e68d26aaf1a8f6e7faab3b44"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e92af7737a94a729225d2a5d180eaaa77fe0bbc1"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Deferred"
}
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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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