{"id":"CVE-2026-64302","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-64302","generatedAt":"2026-10-28T07:03:55.154Z","title":"In the Linux kernel, the following vulnerability has been resolved: x86/mm: Fix freeing of PMD-sized vmemmap pages Commit bf9e4e30f353 (\"x86/mm: use pagetable_free()\"), switched from freeing non-boot page tables through __free_pages() to pagetable_free().","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/mm: Fix freeing of PMD-sized vmemmap pages\n\nCommit bf9e4e30f353 (\"x86/mm: use pagetable_free()\"), switched from\nfreeing non-boot page tables through __free_pages() to\npagetable_free().\n\nHowever, the function is also called to free vmemmap pages.\n\nGiven that vmemmap pages are not page tables, already the page_ptdesc(page)\nis wrong. But worse, pagetable_free() calls:\n\n\t__free_pages(page, compound_order(page));\n\nSince vmemmap pages are not compound pages (see vmemmap_alloc_block())\n-- except for HVO, which doesn't apply here -- only first page of a\nPMD-sized vmemmap page is freed, leaking the other ones.\n\nFix it by properly decoupling pagetable and vmemmap freeing.\nfree_pagetable() no longer has to mess with SECTION_INFO, as only the\nvmemmap is marked like that in register_page_bootmem_memmap().\n\nThe indentation in remove_pmd_table() is messed up. Fix that while\ntouching it.\n\nBootmem info handling will soon be fixed up. For now, handle it\nsimilar to free_pagetable(), just avoiding the ifdef.\n\n[ dhansen: changelog munging. More imperative voice ]","published":"2026-07-25T10:17:11.000Z","lastModified":"2026-09-03T16:11:54.000Z","status":"Analyzed","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":[],"affected":["linux/linux kernel"],"epss":{"score":0.0016,"percentile":0.0513,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.16%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/03f6ecbc446c33b38fd452cd3c494092a8116967","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/39406c05f8f150f1685839acd38ffdd69ff92031","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/add1e4112e00b619614784bf630aeebfdefa23e1","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64302","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}