{"schema":"threatline.record/2","record":{"id":"CVE-2026-93232","aliases":[],"summary":"mm/hugetlb: fix boot panic with CONFIG_DEBUG_VM and HVO bootmem pages","details":"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->vmemmap_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->vmemmap_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.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-93232","source_modified_at":"2026-10-19T09:07:43.993Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"622026e87c4019e609010811757e31193cc23847","lessThan":"2ddf429e25cf8415d9c308f07e64012026bd4d77","status":"affected","versionType":"git"},{"version":"622026e87c4019e609010811757e31193cc23847","lessThan":"c0caeceb0c3899dc42844d3979093b27d1434108","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-93232","source_modified_at":"2026-10-19T09:07:43.993Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"7.1","status":"affected"},{"version":"0","lessThan":"7.1","status":"unaffected","versionType":"semver"},{"version":"7.2.4","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-93232","source_modified_at":"2026-10-19T09:07:43.993Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"2ddf429e25cf8415d9c308f07e64012026bd4d77","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00155,"percentile":0.04316,"score_date":"2026-10-23"},"published_at":"2026-09-24T15:29:22.699Z","modified_at":"2026-10-19T09:07:43.993Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-93232","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:07:43.993Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-93232","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/2ddf429e25cf8415d9c308f07e64012026bd4d77"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/c0caeceb0c3899dc42844d3979093b27d1434108"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:07:43.993Z","content_hash":"79988f7da446fa3762ece4252d5de12481abb3075c197704d0a6cbb92428b95a"}}