CVE-2026-64302
- Source
- https://cve.org/CVERecord?id=CVE-2026-64302
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64302.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-64302
- Downstream
- Related
- Published
- 2026-07-25T08:49:37Z
- Modified
- 2026-09-05T03:30:44Z
- Summary
- x86/mm: Fix freeing of PMD-sized vmemmap pages
- Details
-
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().
However, the function is also called to free vmemmap pages.
Given that vmemmap pages are not page tables, already the page_ptdesc(page) is wrong. But worse, pagetable_free() calls:
__free_pages(page, compound_order(page));Since vmemmap pages are not compound pages (see vmemmap_alloc_block()) -- except for HVO, which doesn't apply here -- only first page of a PMD-sized vmemmap page is freed, leaking the other ones.
Fix it by properly decoupling pagetable and vmemmap freeing. free_pagetable() no longer has to mess with SECTION_INFO, as only the vmemmap is marked like that in register_page_bootmem_memmap().
The indentation in remove_pmd_table() is messed up. Fix that while touching it.
Bootmem info handling will soon be fixed up. For now, handle it similar to free_pagetable(), just avoiding the ifdef.
[ dhansen: changelog munging. More imperative voice ]
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64302.json" }- References
-
- https://git.kernel.org/stable/c/03f6ecbc446c33b38fd452cd3c494092a8116967
- https://git.kernel.org/stable/c/39406c05f8f150f1685839acd38ffdd69ff92031
- https://git.kernel.org/stable/c/add1e4112e00b619614784bf630aeebfdefa23e1
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64302.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-64302
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduceda1593c90896babf33e947910c7aecb9f50bab993Fixedadd1e4112e00b619614784bf630aeebfdefa23e1
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedbf9e4e30f3538391745a99bc2268ec4f5e4a401eFixed03f6ecbc446c33b38fd452cd3c494092a8116967Fixed39406c05f8f150f1685839acd38ffdd69ff92031
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced6.18.7Fixed6.18.39