powerpc/mm: fix wrong addr_pfn tracking in compound vmemmap population
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.
CVE-2026-89961
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-89961
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "f2b79c0d79683d552369bb9a7282c1f0226fc566",
"lessThan": "b96be860673f9fbbf12cdadb0b25fc4d6d4d207f",
"versionType": "git"
},
{
"status": "affected",
"version": "f2b79c0d79683d552369bb9a7282c1f0226fc566",
"lessThan": "e163c7184acf36ac20a248498f4a16016057ca01",
"versionType": "git"
},
{
"status": "affected",
"version": "f2b79c0d79683d552369bb9a7282c1f0226fc566",
"lessThan": "9c914b7a0bd18834505c65f22225ce22c152b2d9",
"versionType": "git"
},
{
"status": "affected",
"version": "f2b79c0d79683d552369bb9a7282c1f0226fc566",
"lessThan": "7968852a7ca3ce81477ec5b4494a28d612f35a97",
"versionType": "git"
},
{
"status": "affected",
"version": "f2b79c0d79683d552369bb9a7282c1f0226fc566",
"lessThan": "89a4ae32764172468dea303eb6ae90fe6c859712",
"versionType": "git"
}
],
"programFiles": [
"arch/powerpc/mm/book3s64/radix_pgtable.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.6"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.6",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.51",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.5",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"arch/powerpc/mm/book3s64/radix_pgtable.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89961
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #36401 · Revision 1
- Added to Heist Feed
- Publisher date