{"id":"CVE-2026-89961","revision":"a34aea9367f5446da39257f6e9e7a6b8","records":[{"revision":"a34aea9367f5446da39257f6e9e7a6b8","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89961","aliases":[],"title":"powerpc/mm: fix wrong addr_pfn tracking in compound vmemmap population","description":"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.","state":0,"publishedAt":"2026-09-16T10:32:43.921+00:00","modifiedAt":"2026-10-19T08:55:35.034+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/powerpc/mm/book3s64/radix_pgtable.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"f2b79c0d79683d552369bb9a7282c1f0226fc566\",\n                            \"lessThan\": \"b96be860673f9fbbf12cdadb0b25fc4d6d4d207f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f2b79c0d79683d552369bb9a7282c1f0226fc566\",\n                            \"lessThan\": \"e163c7184acf36ac20a248498f4a16016057ca01\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f2b79c0d79683d552369bb9a7282c1f0226fc566\",\n                            \"lessThan\": \"9c914b7a0bd18834505c65f22225ce22c152b2d9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f2b79c0d79683d552369bb9a7282c1f0226fc566\",\n                            \"lessThan\": \"7968852a7ca3ce81477ec5b4494a28d612f35a97\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f2b79c0d79683d552369bb9a7282c1f0226fc566\",\n                            \"lessThan\": \"89a4ae32764172468dea303eb6ae90fe6c859712\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/powerpc/mm/book3s64/radix_pgtable.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.6\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.6\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.157\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.110\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.51\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.5\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/b96be860673f9fbbf12cdadb0b25fc4d6d4d207f","https://git.kernel.org/stable/c/e163c7184acf36ac20a248498f4a16016057ca01","https://git.kernel.org/stable/c/9c914b7a0bd18834505c65f22225ce22c152b2d9","https://git.kernel.org/stable/c/7968852a7ca3ce81477ec5b4494a28d612f35a97","https://git.kernel.org/stable/c/89a4ae32764172468dea303eb6ae90fe6c859712"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89961","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89961","identifiers":["CVE-2026-89961"]},"retained":false,"historicalAffected":[]}],"coverage":[]}