FKIE_CVE-2026-80718
Vulnerability from fkie_nvd - Published: 2026-08-28 08:16 - Updated: 2026-08-29 07:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
mm/percpu-km: fix bitmap overflow and accounting in pcpu_create_chunk()
In pcpu_create_chunk(), nr_pages is the total contiguous backing
allocation, i.e., nr_units * pcpu_unit_pages, but pcpu_chunk_populated()
uses it to set chunk->populated, whose size is pcpu_unit_pages, bitmap.
Since bit N in chunk->populated means page offset N inside every unit is
backed. When nr_units > 1, the function writes beyond chunk->populated.
Fix it by using chunk->nr_pages.
It also fixes the global pcpu_nr_empty_pop_pages accounting, since
pcpu_balance_free() only iterates up to chunk->nr_pages.
Commit a63d4ac4ab609 ("percpu: make percpu-km set chunk->populated bitmap
properly") introduced the bitmap overflow issue. Later, commit
b539b87fed37f ("percpu: implmeent pcpu_nr_empty_pop_pages and
chunk->nr_populated") added pcpu_nr_empty_pop_pages and caused the
accounting issue.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"mm/percpu-km.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "5f43d2c1bea280dcdfabaf156c25e7402fb8039f",
"status": "affected",
"version": "a63d4ac4ab6094c051a5a240260d16117a7a2f86",
"versionType": "git"
},
{
"lessThan": "92c43ac3c2b09eb16162e8144e73c00b7c3e29d6",
"status": "affected",
"version": "a63d4ac4ab6094c051a5a240260d16117a7a2f86",
"versionType": "git"
},
{
"lessThan": "6fc7da2a052f2825fff785e860e67183f5acaaba",
"status": "affected",
"version": "a63d4ac4ab6094c051a5a240260d16117a7a2f86",
"versionType": "git"
},
{
"lessThan": "01504da375f5b19df195cb1cb1cf1dd184318f97",
"status": "affected",
"version": "a63d4ac4ab6094c051a5a240260d16117a7a2f86",
"versionType": "git"
},
{
"lessThan": "a6940b84c8c035da465b7165fdfcfb005545724e",
"status": "affected",
"version": "a63d4ac4ab6094c051a5a240260d16117a7a2f86",
"versionType": "git"
},
{
"lessThan": "32134cf9211b83bed9076d0739c5906fbea4c763",
"status": "affected",
"version": "a63d4ac4ab6094c051a5a240260d16117a7a2f86",
"versionType": "git"
},
{
"lessThan": "5c7fc39bf19abb38a996aaad77b3e3a8f48581c3",
"status": "affected",
"version": "a63d4ac4ab6094c051a5a240260d16117a7a2f86",
"versionType": "git"
},
{
"lessThan": "89b1b79c308818a715e75f28744b70d8940a07c9",
"status": "affected",
"version": "a63d4ac4ab6094c051a5a240260d16117a7a2f86",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"mm/percpu-km.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.18"
},
{
"lessThan": "3.18",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.151",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.103",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"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\nmm/percpu-km: fix bitmap overflow and accounting in pcpu_create_chunk()\n\nIn pcpu_create_chunk(), nr_pages is the total contiguous backing\nallocation, i.e., nr_units * pcpu_unit_pages, but pcpu_chunk_populated()\nuses it to set chunk-\u003epopulated, whose size is pcpu_unit_pages, bitmap. \nSince bit N in chunk-\u003epopulated means page offset N inside every unit is\nbacked. When nr_units \u003e 1, the function writes beyond chunk-\u003epopulated. \nFix it by using chunk-\u003enr_pages.\n\nIt also fixes the global pcpu_nr_empty_pop_pages accounting, since\npcpu_balance_free() only iterates up to chunk-\u003enr_pages.\n\nCommit a63d4ac4ab609 (\"percpu: make percpu-km set chunk-\u003epopulated bitmap\nproperly\") introduced the bitmap overflow issue. Later, commit\nb539b87fed37f (\"percpu: implmeent pcpu_nr_empty_pop_pages and\nchunk-\u003enr_populated\") added pcpu_nr_empty_pop_pages and caused the\naccounting issue."
}
],
"id": "CVE-2026-80718",
"lastModified": "2026-08-29T07:16:53.323",
"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": "2026-08-28T08:16:57.563",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/01504da375f5b19df195cb1cb1cf1dd184318f97"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/32134cf9211b83bed9076d0739c5906fbea4c763"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/5c7fc39bf19abb38a996aaad77b3e3a8f48581c3"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/5f43d2c1bea280dcdfabaf156c25e7402fb8039f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/6fc7da2a052f2825fff785e860e67183f5acaaba"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/89b1b79c308818a715e75f28744b70d8940a07c9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/92c43ac3c2b09eb16162e8144e73c00b7c3e29d6"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a6940b84c8c035da465b7165fdfcfb005545724e"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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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.
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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