{"api_version":"1","generated_at":"2026-09-11T19:22:25+00:00","cve":"CVE-2026-80893","urls":{"html":"https://cve.report/CVE-2026-80893","api":"https://cve.report/api/cve/CVE-2026-80893.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80893","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80893"},"summary":{"title":"mm/hugetlb: fix swap entry corruption when clearing uffd-wp at fork()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb: fix swap entry corruption when clearing uffd-wp at fork()\n\ncopy_hugetlb_page_range() clears the uffd-wp bit of migration and hwpoison\nentries with huge_pte_clear_uffd_wp(), which operates on the present-PTE\nbit position.  Swap entries keep the uffd-wp state elsewhere -- the\nmigration branch reads and sets it with pte_swp_uffd_wp() and\npte_swp_mkuffd_wp() -- and the present-PTE position falls into the swap\npayload.  On x86-64 it lands in the inverted swap offset, where a\nnaturally-aligned hugetlb PFN always has the affected bit set, so the\nclear advances the encoded PFN by two pages.\n\nNo userfaultfd needs to be involved: the clear is guarded only by the\nchild VMA not being uffd-wp registered, so a plain fork() with an\nin-flight hugetlb migration entry (or a poisoned hugetlb page) corrupts\nthe entry copied into the child.  Instrumenting the clear and forking\nafter MADV_HWPOISON on a 2MB anon hugetlb page shows:\n\n  offset before=120e00\n  offset after =120e02\n\nThe fallout is mostly latent: rmap walks match migration entries by folio\nrange and remove_migration_pte() rebuilds the PTE from the folio, so a\nwithin-folio PFN skew heals once migration completes.  But any path that\nre-encodes the corrupted offset -- e.g.  hugetlb_change_protection()\nrewriting a writable migration entry via\nmake_readable_migration_entry(swp_offset(entry)) -- propagates it.\n\nMigration entries legitimately carry uffd-wp, so clear it with\npte_swp_clear_uffd_wp(), matching copy_nonpresent_pte() and\nmove_huge_pte().\n\nA hwpoison entry, on the other hand, never carries the uffd-wp bit: it is\ninstalled fresh by make_hwpoison_entry() (try_to_unmap_one() does not\npreserve uffd-wp on the hwpoison path) and hugetlb_change_protection()\nleaves hwpoison entries untouched.  There was nothing to clear there, only\nthe corruption, so drop the clear entirely.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-04 18:17:57","updated_at":"2026-09-04 18:17:57"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/83abe2fd5b3aeb3123b5408a5a91709c5538fb23","name":"https://git.kernel.org/stable/c/83abe2fd5b3aeb3123b5408a5a91709c5538fb23","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f1b1311c0352873137768bac5a126e491271a747","name":"https://git.kernel.org/stable/c/f1b1311c0352873137768bac5a126e491271a747","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/69cb5825d9988c7944bc9f1dc08cb233655405a7","name":"https://git.kernel.org/stable/c/69cb5825d9988c7944bc9f1dc08cb233655405a7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2b9a07002c2f296aa6a9c591213933d3492e3089","name":"https://git.kernel.org/stable/c/2b9a07002c2f296aa6a9c591213933d3492e3089","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8b0de7005b148738d79d6c45594d566489948a68","name":"https://git.kernel.org/stable/c/8b0de7005b148738d79d6c45594d566489948a68","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2fa11c60c9c06bafc19cf4d9efdaa36a38079e87","name":"https://git.kernel.org/stable/c/2fa11c60c9c06bafc19cf4d9efdaa36a38079e87","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80893","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80893","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bc70fbf269fdff410b0b6d75c3770b9f59117b90 f1b1311c0352873137768bac5a126e491271a747 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bc70fbf269fdff410b0b6d75c3770b9f59117b90 69cb5825d9988c7944bc9f1dc08cb233655405a7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bc70fbf269fdff410b0b6d75c3770b9f59117b90 8b0de7005b148738d79d6c45594d566489948a68 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bc70fbf269fdff410b0b6d75c3770b9f59117b90 2b9a07002c2f296aa6a9c591213933d3492e3089 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bc70fbf269fdff410b0b6d75c3770b9f59117b90 2fa11c60c9c06bafc19cf4d9efdaa36a38079e87 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected bc70fbf269fdff410b0b6d75c3770b9f59117b90 83abe2fd5b3aeb3123b5408a5a91709c5538fb23 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.19","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.19 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.183 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.151 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.103 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.44 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.8 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"80893","cve":"CVE-2026-80893","epss":"0.001730000","percentile":"0.068290000","score_date":"2026-09-07","updated_at":"2026-09-08 00:05:26"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["mm/hugetlb.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"f1b1311c0352873137768bac5a126e491271a747","status":"affected","version":"bc70fbf269fdff410b0b6d75c3770b9f59117b90","versionType":"git"},{"lessThan":"69cb5825d9988c7944bc9f1dc08cb233655405a7","status":"affected","version":"bc70fbf269fdff410b0b6d75c3770b9f59117b90","versionType":"git"},{"lessThan":"8b0de7005b148738d79d6c45594d566489948a68","status":"affected","version":"bc70fbf269fdff410b0b6d75c3770b9f59117b90","versionType":"git"},{"lessThan":"2b9a07002c2f296aa6a9c591213933d3492e3089","status":"affected","version":"bc70fbf269fdff410b0b6d75c3770b9f59117b90","versionType":"git"},{"lessThan":"2fa11c60c9c06bafc19cf4d9efdaa36a38079e87","status":"affected","version":"bc70fbf269fdff410b0b6d75c3770b9f59117b90","versionType":"git"},{"lessThan":"83abe2fd5b3aeb3123b5408a5a91709c5538fb23","status":"affected","version":"bc70fbf269fdff410b0b6d75c3770b9f59117b90","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["mm/hugetlb.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.19"},{"lessThan":"5.19","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.183","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.151","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.103","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.44","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.8","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.183","versionStartIncluding":"5.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.151","versionStartIncluding":"5.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.103","versionStartIncluding":"5.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.44","versionStartIncluding":"5.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.8","versionStartIncluding":"5.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"5.19","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb: fix swap entry corruption when clearing uffd-wp at fork()\n\ncopy_hugetlb_page_range() clears the uffd-wp bit of migration and hwpoison\nentries with huge_pte_clear_uffd_wp(), which operates on the present-PTE\nbit position.  Swap entries keep the uffd-wp state elsewhere -- the\nmigration branch reads and sets it with pte_swp_uffd_wp() and\npte_swp_mkuffd_wp() -- and the present-PTE position falls into the swap\npayload.  On x86-64 it lands in the inverted swap offset, where a\nnaturally-aligned hugetlb PFN always has the affected bit set, so the\nclear advances the encoded PFN by two pages.\n\nNo userfaultfd needs to be involved: the clear is guarded only by the\nchild VMA not being uffd-wp registered, so a plain fork() with an\nin-flight hugetlb migration entry (or a poisoned hugetlb page) corrupts\nthe entry copied into the child.  Instrumenting the clear and forking\nafter MADV_HWPOISON on a 2MB anon hugetlb page shows:\n\n  offset before=120e00\n  offset after =120e02\n\nThe fallout is mostly latent: rmap walks match migration entries by folio\nrange and remove_migration_pte() rebuilds the PTE from the folio, so a\nwithin-folio PFN skew heals once migration completes.  But any path that\nre-encodes the corrupted offset -- e.g.  hugetlb_change_protection()\nrewriting a writable migration entry via\nmake_readable_migration_entry(swp_offset(entry)) -- propagates it.\n\nMigration entries legitimately carry uffd-wp, so clear it with\npte_swp_clear_uffd_wp(), matching copy_nonpresent_pte() and\nmove_huge_pte().\n\nA hwpoison entry, on the other hand, never carries the uffd-wp bit: it is\ninstalled fresh by make_hwpoison_entry() (try_to_unmap_one() does not\npreserve uffd-wp on the hwpoison path) and hugetlb_change_protection()\nleaves hwpoison entries untouched.  There was nothing to clear there, only\nthe corruption, so drop the clear entirely."}],"providerMetadata":{"dateUpdated":"2026-09-04T17:11:09.199Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/f1b1311c0352873137768bac5a126e491271a747"},{"url":"https://git.kernel.org/stable/c/69cb5825d9988c7944bc9f1dc08cb233655405a7"},{"url":"https://git.kernel.org/stable/c/8b0de7005b148738d79d6c45594d566489948a68"},{"url":"https://git.kernel.org/stable/c/2b9a07002c2f296aa6a9c591213933d3492e3089"},{"url":"https://git.kernel.org/stable/c/2fa11c60c9c06bafc19cf4d9efdaa36a38079e87"},{"url":"https://git.kernel.org/stable/c/83abe2fd5b3aeb3123b5408a5a91709c5538fb23"}],"title":"mm/hugetlb: fix swap entry corruption when clearing uffd-wp at fork()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80893","datePublished":"2026-09-04T17:11:09.199Z","dateReserved":"2026-08-26T14:34:25.800Z","dateUpdated":"2026-09-04T17:11:09.199Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-04 18:17:57","lastModifiedDate":"2026-09-04 18:17:57","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"80893","Ordinal":"1","Title":"mm/hugetlb: fix swap entry corruption when clearing uffd-wp at f","CVE":"CVE-2026-80893","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80893","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb: fix swap entry corruption when clearing uffd-wp at fork()\n\ncopy_hugetlb_page_range() clears the uffd-wp bit of migration and hwpoison\nentries with huge_pte_clear_uffd_wp(), which operates on the present-PTE\nbit position.  Swap entries keep the uffd-wp state elsewhere -- the\nmigration branch reads and sets it with pte_swp_uffd_wp() and\npte_swp_mkuffd_wp() -- and the present-PTE position falls into the swap\npayload.  On x86-64 it lands in the inverted swap offset, where a\nnaturally-aligned hugetlb PFN always has the affected bit set, so the\nclear advances the encoded PFN by two pages.\n\nNo userfaultfd needs to be involved: the clear is guarded only by the\nchild VMA not being uffd-wp registered, so a plain fork() with an\nin-flight hugetlb migration entry (or a poisoned hugetlb page) corrupts\nthe entry copied into the child.  Instrumenting the clear and forking\nafter MADV_HWPOISON on a 2MB anon hugetlb page shows:\n\n  offset before=120e00\n  offset after =120e02\n\nThe fallout is mostly latent: rmap walks match migration entries by folio\nrange and remove_migration_pte() rebuilds the PTE from the folio, so a\nwithin-folio PFN skew heals once migration completes.  But any path that\nre-encodes the corrupted offset -- e.g.  hugetlb_change_protection()\nrewriting a writable migration entry via\nmake_readable_migration_entry(swp_offset(entry)) -- propagates it.\n\nMigration entries legitimately carry uffd-wp, so clear it with\npte_swp_clear_uffd_wp(), matching copy_nonpresent_pte() and\nmove_huge_pte().\n\nA hwpoison entry, on the other hand, never carries the uffd-wp bit: it is\ninstalled fresh by make_hwpoison_entry() (try_to_unmap_one() does not\npreserve uffd-wp on the hwpoison path) and hugetlb_change_protection()\nleaves hwpoison entries untouched.  There was nothing to clear there, only\nthe corruption, so drop the clear entirely.","Type":"Description","Title":"mm/hugetlb: fix swap entry corruption when clearing uffd-wp at f"}]}}}