CVE-2026-93232

CVE CVE-2026-93232EUVD EUVD-2026-86237Published 2026-09-24T15:29:22.000Z

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: fix boot panic with CONFIG_DEBUG_VM and HVO bootmem pages Patch series "mm: Refactor bootmem gigantic hugepage allocation", v4. This series is split out from the earlier larger series "mm: Generalize HVO for HugeTLB and device DAX" [1]. It collects the first 19 patches of that series as a standalone set of fixes and preparatory cleanups around bootmem HugeTLB handling, sparse initialization ordering, and related vmemmap setup. The first patches fix a few bugs found while reviewing the existing code, including incorrect bootmem HVO handling, wrong vmemmap registration arguments, a powerpc compound-vmemmap tracking bug, and too-late initialization of gigantic bootmem HugeTLB struct pages. The rest of the series reorders early memory initialization so the relevant zone state is available before sparse and HugeTLB boot-time setup runs, then simplifies the remaining bootmem gigantic hugepage allocation path and removes code made obsolete by that rework. At a high level: - patches [1-4] fix boot-time and arch-specific bugs - patches [5-12] reorder and simplify sparse/mm/hugetlb early init - patches [13-19] refactor bootmem gigantic hugepage allocation and remove obsolete helpers and state This patch (of 19): Commit 622026e87c40 ("mm/hugetlb: remove fake head pages") switched HVO to reuse per-zone shared tail pages from zone->vmemmap_tails[]. Those shared tail pages were initialized in hugetlb_vmemmap_init(), but bootmem HugeTLB folios are prepared earlier from gather_bootmem_prealloc(). With hugetlb_free_vmemmap=on, prep_and_add_bootmem_folios() can access pageblock flags on bootmem HugeTLB pages whose mirrored tail struct pages already point to the shared tail page. On CONFIG_DEBUG_VM kernels, get_pfnblock_bitmap_bitidx() then dereferences the still-uninitialized shared tail page and can panic during boot. Initialize zone->vmemmap_tails[] from gather_bootmem_prealloc(), before bootmem HugeTLB folios are processed, and drop the later initialization from hugetlb_vmemmap_init(). This bug only affects CONFIG_DEBUG_VM kernels, where the relevant assertion is evaluated.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux 7.1; 622026e87c4019e609010811757e31193cc23847 <c0caeceb0c3899dc42844d3979093b27d1434108; patch: 7.2.4; 622026e87c4019e609010811757e31193cc23847 <2ddf429e25cf8415d9c308f07e64012026bd4d77; patch: 7.3-rc1; patch: 0

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

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