# cveboard — Historical CVE brief

## Instructions for the operator's AI
- Verify the actual environment, vendor, product, platform and installed versions against the current authoritative advisory and release information before proposing a change. Preserve each product entry's platforms, default status and version/change boundaries; never infer a fix from a range endpoint or an unaffected entry.
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Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.
Exploitation unknown; this catalogue does not assess exploitation.

## Source facts (JSON-quoted data)
CNA source text (English)
id: "CVE-2026-93232"
idYear: 2026
status: "PUBLISHED"
publishedAt: "2026-09-24T15:29:22.699Z"
updatedAt: "2026-10-19T09:07:43.993Z"
importedAt: "2026-10-24T01:58:35.090Z"
snapshot: {"id":"cve_2026-10-24_midnight_baseline","at":"2026-10-24T00:00:00.000Z","source":"https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"}
url: "https://cveboard.org/cve/CVE-2026-93232"
json: "https://cveboard.org/cve/CVE-2026-93232.json"
sourceURL: "https://www.cve.org/CVERecord?id=CVE-2026-93232"
title: "mm/hugetlb: fix boot panic with CONFIG_DEBUG_VM and HVO bootmem pages"
summary: "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb: fix boot panic with CONFIG_DEBUG_VM and HVO bootmem pages\n\nPatch series \"mm: Refactor bootmem gigantic hugepage allocation\", v4.\n\nThis series is split out from the earlier larger series \"mm: Generalize\nHVO for HugeTLB and device DAX\" [1].  It collects the first 19 patches of\nthat series as a standalone set of fixes and preparatory cleanups around\nbootmem HugeTLB handling, sparse initialization ordering, and related\nvmemmap setup.\n\nThe first patches fix a few bugs found while reviewing the existing code,\nincluding incorrect bootmem HVO handling, wrong vmemmap registration\narguments, a powerpc compound-vmemmap tracking bug, and too-late\ninitialization of gigantic bootmem HugeTLB struct pages.\n\nThe rest of the series reorders early memory initialization so the\nrelevant zone state is available before sparse and HugeTLB boot-time setup\nruns, then simplifies the remaining bootmem gigantic hugepage allocation\npath and removes code made obsolete by that rework.\n\nAt a high level:\n  - patches [1-4] fix boot-time and arch-specific bugs\n  - patches [5-12] reorder and simplify sparse/mm/hugetlb early init\n  - patches [13-19] refactor bootmem gigantic hugepage allocation and\n    remove obsolete helpers and state\n\n\nThis patch (of 19):\n\nCommit 622026e87c40 (\"mm/hugetlb: remove fake head pages\") switched\nHVO to reuse per-zone shared tail pages from zone-\u003evmemmap_tails[].\n\nThose shared tail pages were initialized in hugetlb_vmemmap_init(), but\nbootmem HugeTLB folios are prepared earlier from\ngather_bootmem_prealloc().  With hugetlb_free_vmemmap=on,\nprep_and_add_bootmem_folios() can access pageblock flags on bootmem\nHugeTLB pages whose mirrored tail struct pages already point to the shared\ntail page.  On CONFIG_DEBUG_VM kernels, get_pfnblock_bitmap_bitidx() then\ndereferences the still-uninitialized shared tail page and can panic during\nboot.\n\nInitialize zone-\u003evmemmap_tails[] from gather_bootmem_prealloc(), before\nbootmem HugeTLB folios are processed, and drop the later initialization\nfrom hugetlb_vmemmap_init().\n\nThis bug only affects CONFIG_DEBUG_VM kernels, where the relevant\nassertion is evaluated."
affected: [{"versions":[{"version":"622026e87c4019e609010811757e31193cc23847","status":"affected","versionType":"git","lessThan":"2ddf429e25cf8415d9c308f07e64012026bd4d77"},{"version":"622026e87c4019e609010811757e31193cc23847","status":"affected","versionType":"git","lessThan":"c0caeceb0c3899dc42844d3979093b27d1434108"}],"vendor":"Linux","product":"Linux","defaultStatus":"unaffected"},{"versions":[{"version":"7.1","status":"affected"},{"version":"0","status":"unaffected","versionType":"semver","lessThan":"7.1"},{"version":"7.2.4","status":"unaffected","versionType":"semver","lessThanOrEqual":"7.2.*"},{"version":"7.3","status":"unaffected","versionType":"original_commit_for_fix","lessThanOrEqual":"*"}],"vendor":"Linux","product":"Linux","defaultStatus":"affected"}]

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