FKIE_CVE-2026-89961
Vulnerability from fkie_nvd - Published: 2026-09-16 11:17 - Updated: 2026-09-16 15:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
powerpc/mm: fix wrong addr_pfn tracking in compound vmemmap population
vmemmap_populate_compound_pages() uses addr_pfn to determine the PFN
offset within a compound page and to decide whether the current vmemmap
slot should be populated as a head page mapping or should reuse a tail
page mapping.
However, addr_pfn is advanced manually in parallel with addr. The loop
itself progresses in vmemmap address space, so each PAGE_SIZE step in addr
covers PAGE_SIZE / sizeof(struct page) struct page slots. Since addr_pfn
is compared against nr_pages in data-PFN units, it should advance by the
same number of PFNs. The existing manual increments do not match that and
therefore do not reliably track the PFN corresponding to the current addr.
As a result, pfn_offset can be computed from the wrong PFN and the code
can make the head/tail decision for the wrong compound-page position.
Fix this by deriving addr_pfn directly from the current vmemmap address
instead of carrying it as loop state.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"arch/powerpc/mm/book3s64/radix_pgtable.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "b96be860673f9fbbf12cdadb0b25fc4d6d4d207f",
"status": "affected",
"version": "f2b79c0d79683d552369bb9a7282c1f0226fc566",
"versionType": "git"
},
{
"lessThan": "e163c7184acf36ac20a248498f4a16016057ca01",
"status": "affected",
"version": "f2b79c0d79683d552369bb9a7282c1f0226fc566",
"versionType": "git"
},
{
"lessThan": "9c914b7a0bd18834505c65f22225ce22c152b2d9",
"status": "affected",
"version": "f2b79c0d79683d552369bb9a7282c1f0226fc566",
"versionType": "git"
},
{
"lessThan": "7968852a7ca3ce81477ec5b4494a28d612f35a97",
"status": "affected",
"version": "f2b79c0d79683d552369bb9a7282c1f0226fc566",
"versionType": "git"
},
{
"lessThan": "89a4ae32764172468dea303eb6ae90fe6c859712",
"status": "affected",
"version": "f2b79c0d79683d552369bb9a7282c1f0226fc566",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"arch/powerpc/mm/book3s64/radix_pgtable.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.6"
},
{
"lessThan": "6.6",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.51",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"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\npowerpc/mm: fix wrong addr_pfn tracking in compound vmemmap population\n\nvmemmap_populate_compound_pages() uses addr_pfn to determine the PFN\noffset within a compound page and to decide whether the current vmemmap\nslot should be populated as a head page mapping or should reuse a tail\npage mapping.\n\nHowever, addr_pfn is advanced manually in parallel with addr. The loop\nitself progresses in vmemmap address space, so each PAGE_SIZE step in addr\ncovers PAGE_SIZE / sizeof(struct page) struct page slots. Since addr_pfn\nis compared against nr_pages in data-PFN units, it should advance by the\nsame number of PFNs. The existing manual increments do not match that and\ntherefore do not reliably track the PFN corresponding to the current addr.\n\nAs a result, pfn_offset can be computed from the wrong PFN and the code\ncan make the head/tail decision for the wrong compound-page position.\n\nFix this by deriving addr_pfn directly from the current vmemmap address\ninstead of carrying it as loop state."
}
],
"id": "CVE-2026-89961",
"lastModified": "2026-09-16T15:18:20.703",
"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": "2026-09-16T11:17:06.570",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7968852a7ca3ce81477ec5b4494a28d612f35a97"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/89a4ae32764172468dea303eb6ae90fe6c859712"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/9c914b7a0bd18834505c65f22225ce22c152b2d9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b96be860673f9fbbf12cdadb0b25fc4d6d4d207f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e163c7184acf36ac20a248498f4a16016057ca01"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
Loading…
Loading…
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.
Loading…
Loading…
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.
Loading…
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.
Loading…