FKIE_CVE-2025-40124
Vulnerability from fkie_nvd - Published: 2025-11-12 11:15 - Updated: 2026-07-30 06:24
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
sparc: fix accurate exception reporting in copy_{from_to}_user for UltraSPARC III
Anthony Yznaga tracked down that a BUG_ON in ext4 code with large folios
enabled resulted from copy_from_user() returning impossibly large values
greater than the size to be copied. This lead to __copy_from_iter()
returning impossible values instead of the actual number of bytes it was
able to copy.
The BUG_ON has been reported in
https://lore.kernel.org/r/b14f55642207e63e907965e209f6323a0df6dcee.camel@physik.fu-berlin.de
The referenced commit introduced exception handlers on user-space memory
references in copy_from_user and copy_to_user. These handlers return from
the respective function and calculate the remaining bytes left to copy
using the current register contents. The exception handlers expect that
%o2 has already been masked during the bulk copy loop, but the masking was
performed after that loop. This will fix the return value of copy_from_user
and copy_to_user in the faulting case. The behaviour of memcpy stays
unchanged.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"arch/sparc/lib/U3memcpy.S"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "fdd43fe6d286f27b826572457a89c926f97e2d3a",
"status": "affected",
"version": "ee841d0aff649164080e445e84885015958d8ff4",
"versionType": "git"
},
{
"lessThan": "1198077606aeffb102587c6ea079ce99641c99d4",
"status": "affected",
"version": "ee841d0aff649164080e445e84885015958d8ff4",
"versionType": "git"
},
{
"lessThan": "1857cdca12c4aff58bf26a7005a4d02850c29927",
"status": "affected",
"version": "ee841d0aff649164080e445e84885015958d8ff4",
"versionType": "git"
},
{
"lessThan": "91eda032eb16e5d2be27c95584665bc555bb5a90",
"status": "affected",
"version": "ee841d0aff649164080e445e84885015958d8ff4",
"versionType": "git"
},
{
"lessThan": "dc766c4830a7e1e1ee9d7f77d4ab344f2eb23c8e",
"status": "affected",
"version": "ee841d0aff649164080e445e84885015958d8ff4",
"versionType": "git"
},
{
"lessThan": "5ef9c94d7110e90260c06868cf1dcf899b9f25ee",
"status": "affected",
"version": "ee841d0aff649164080e445e84885015958d8ff4",
"versionType": "git"
},
{
"lessThan": "e50377c6b3f278c9f3ef017ffce17f5fcc9dace4",
"status": "affected",
"version": "ee841d0aff649164080e445e84885015958d8ff4",
"versionType": "git"
},
{
"lessThan": "47b49c06eb62504075f0f2e2227aee2e2c2a58b3",
"status": "affected",
"version": "ee841d0aff649164080e445e84885015958d8ff4",
"versionType": "git"
},
{
"status": "affected",
"version": "1c7e17b1c4d60cc5aa575460f7efb73686dd3b39",
"versionType": "git"
},
{
"status": "affected",
"version": "ac663c54f40b2830b1ca32d1ae9d683fe248b14c",
"versionType": "git"
},
{
"lessThan": "4.5",
"status": "affected",
"version": "4.4.34",
"versionType": "semver"
},
{
"lessThan": "4.9",
"status": "affected",
"version": "4.8.10",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"arch/sparc/lib/U3memcpy.S"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.9"
},
{
"lessThan": "4.9",
"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": "5.15.195",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.156",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.112",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.53",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.17.*",
"status": "unaffected",
"version": "6.17.3",
"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\nsparc: fix accurate exception reporting in copy_{from_to}_user for UltraSPARC III\n\nAnthony Yznaga tracked down that a BUG_ON in ext4 code with large folios\nenabled resulted from copy_from_user() returning impossibly large values\ngreater than the size to be copied. This lead to __copy_from_iter()\nreturning impossible values instead of the actual number of bytes it was\nable to copy.\n\nThe BUG_ON has been reported in\nhttps://lore.kernel.org/r/b14f55642207e63e907965e209f6323a0df6dcee.camel@physik.fu-berlin.de\n\nThe referenced commit introduced exception handlers on user-space memory\nreferences in copy_from_user and copy_to_user. These handlers return from\nthe respective function and calculate the remaining bytes left to copy\nusing the current register contents. The exception handlers expect that\n%o2 has already been masked during the bulk copy loop, but the masking was\nperformed after that loop. This will fix the return value of copy_from_user\nand copy_to_user in the faulting case. The behaviour of memcpy stays\nunchanged."
}
],
"id": "CVE-2025-40124",
"lastModified": "2026-07-30T06:24:12.727",
"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": "2025-11-12T11:15:41.920",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1198077606aeffb102587c6ea079ce99641c99d4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1857cdca12c4aff58bf26a7005a4d02850c29927"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/47b49c06eb62504075f0f2e2227aee2e2c2a58b3"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/5ef9c94d7110e90260c06868cf1dcf899b9f25ee"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/91eda032eb16e5d2be27c95584665bc555bb5a90"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/dc766c4830a7e1e1ee9d7f77d4ab344f2eb23c8e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e50377c6b3f278c9f3ef017ffce17f5fcc9dace4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/fdd43fe6d286f27b826572457a89c926f97e2d3a"
}
],
"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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