{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-31466", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.097Z", "datePublished": "2026-04-22T13:53:56.259Z", "dateUpdated": "2026-04-22T13:53:56.259Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-04-22T13:53:56.259Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/huge_memory: fix folio isn't locked in softleaf_to_folio()\n\nOn arm64 server, we found folio that get from migration entry isn't locked\nin softleaf_to_folio(). This issue triggers when mTHP splitting and\nzap_nonpresent_ptes() races, and the root cause is lack of memory barrier\nin softleaf_to_folio(). The race is as follows:\n\n\tCPU0 CPU1\n\ndeferred_split_scan() zap_nonpresent_ptes()\n lock folio\n split_folio()\n unmap_folio()\n change ptes to migration entries\n __split_folio_to_order() softleaf_to_folio()\n set flags(including PG_locked) for tail pages folio = pfn_folio(softleaf_to_pfn(entry))\n smp_wmb() VM_WARN_ON_ONCE(!folio_test_locked(folio))\n prep_compound_page() for tail pages\n\nIn __split_folio_to_order(), smp_wmb() guarantees page flags of tail pages\nare visible before the tail page becomes non-compound. smp_wmb() should\nbe paired with smp_rmb() in softleaf_to_folio(), which is missed. As a\nresult, if zap_nonpresent_ptes() accesses migration entry that stores tail\npfn, softleaf_to_folio() may see the updated compound_head of tail page\nbefore page->flags.\n\nThis issue will trigger VM_WARN_ON_ONCE() in pfn_swap_entry_folio()\nbecause of the race between folio split and zap_nonpresent_ptes()\nleading to a folio incorrectly undergoing modification without a folio\nlock being held.\n\nThis is a BUG_ON() before commit 93976a20345b (\"mm: eliminate further\nswapops predicates\"), which in merged in v6.19-rc1.\n\nTo fix it, add missing smp_rmb() if the softleaf entry is migration entry\nin softleaf_to_folio() and softleaf_to_page().\n\n[tujinjiang@huawei.com: update function name and comments]"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/linux/leafops.h"], "versions": [{"version": "e9b61f19858a5d6c42ce2298cf138279375d0d9b", "lessThan": "426ee10711586617da869c8bb798214965337617", "status": "affected", "versionType": "git"}, {"version": "e9b61f19858a5d6c42ce2298cf138279375d0d9b", "lessThan": "f1acf5887c2bbaf998dc3fe32c72b7a8b84a3ddd", "status": "affected", "versionType": "git"}, {"version": "e9b61f19858a5d6c42ce2298cf138279375d0d9b", "lessThan": "722cfaf6b31d31123439e67b5deac6b1261a3dea", "status": "affected", "versionType": "git"}, {"version": "e9b61f19858a5d6c42ce2298cf138279375d0d9b", "lessThan": "7ddcf4a245c1c5a91fdd9698757e3d95179ffe41", "status": "affected", "versionType": "git"}, {"version": "e9b61f19858a5d6c42ce2298cf138279375d0d9b", "lessThan": "b8c49ad888892ad7b77062b9c102b799a3e9b4f8", "status": "affected", "versionType": "git"}, {"version": "e9b61f19858a5d6c42ce2298cf138279375d0d9b", "lessThan": "7ad1997b9bc8032603df8f091761114479285769", "status": "affected", "versionType": "git"}, {"version": "e9b61f19858a5d6c42ce2298cf138279375d0d9b", "lessThan": "8bfb8414e9f2ce6f5f2f0e3d0da52f2d132128e7", "status": "affected", "versionType": "git"}, {"version": "e9b61f19858a5d6c42ce2298cf138279375d0d9b", "lessThan": "4c5e7f0fcd592801c9cc18f29f80fbee84eb8669", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/linux/leafops.h"], "versions": [{"version": "4.5", "status": "affected"}, {"version": "0", "lessThan": "4.5", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.253", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.203", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.168", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.134", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.81", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.21", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.11", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "5.10.253"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "5.15.203"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.1.168"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.6.134"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.12.81"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.18.21"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.19.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "7.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/426ee10711586617da869c8bb798214965337617"}, {"url": "https://git.kernel.org/stable/c/f1acf5887c2bbaf998dc3fe32c72b7a8b84a3ddd"}, {"url": "https://git.kernel.org/stable/c/722cfaf6b31d31123439e67b5deac6b1261a3dea"}, {"url": "https://git.kernel.org/stable/c/7ddcf4a245c1c5a91fdd9698757e3d95179ffe41"}, {"url": "https://git.kernel.org/stable/c/b8c49ad888892ad7b77062b9c102b799a3e9b4f8"}, {"url": "https://git.kernel.org/stable/c/7ad1997b9bc8032603df8f091761114479285769"}, {"url": "https://git.kernel.org/stable/c/8bfb8414e9f2ce6f5f2f0e3d0da52f2d132128e7"}, {"url": "https://git.kernel.org/stable/c/4c5e7f0fcd592801c9cc18f29f80fbee84eb8669"}], "title": "mm/huge_memory: fix folio isn't locked in softleaf_to_folio()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/huge_memory: fix folio isn't locked in softleaf_to_folio()\n\nOn arm64 server, we found folio that get from migration entry isn't locked\nin softleaf_to_folio(). This issue triggers when mTHP splitting and\nzap_nonpresent_ptes() races, and the root cause is lack of memory barrier\nin softleaf_to_folio(). The race is as follows:\n\n\tCPU0 CPU1\n\ndeferred_split_scan() zap_nonpresent_ptes()\n lock folio\n split_folio()\n unmap_folio()\n change ptes to migration entries\n __split_folio_to_order() softleaf_to_folio()\n set flags(including PG_locked) for tail pages folio = pfn_folio(softleaf_to_pfn(entry))\n smp_wmb() VM_WARN_ON_ONCE(!folio_test_locked(folio))\n prep_compound_page() for tail pages\n\nIn __split_folio_to_order(), smp_wmb() guarantees page flags of tail pages\nare visible before the tail page becomes non-compound. smp_wmb() should\nbe paired with smp_rmb() in softleaf_to_folio(), which is missed. As a\nresult, if zap_nonpresent_ptes() accesses migration entry that stores tail\npfn, softleaf_to_folio() may see the updated compound_head of tail page\nbefore page->flags.\n\nThis issue will trigger VM_WARN_ON_ONCE() in pfn_swap_entry_folio()\nbecause of the race between folio split and zap_nonpresent_ptes()\nleading to a folio incorrectly undergoing modification without a folio\nlock being held.\n\nThis is a BUG_ON() before commit 93976a20345b (\"mm: eliminate further\nswapops predicates\"), which in merged in v6.19-rc1.\n\nTo fix it, add missing smp_rmb() if the softleaf entry is migration entry\nin softleaf_to_folio() and softleaf_to_page().\n\n[tujinjiang@huawei.com: update function name and comments]"}], "id": "CVE-2026-31466", "lastModified": "2026-04-22T14:16:42.780", "metrics": {}, "published": "2026-04-22T14:16:42.780", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/426ee10711586617da869c8bb798214965337617"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4c5e7f0fcd592801c9cc18f29f80fbee84eb8669"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/722cfaf6b31d31123439e67b5deac6b1261a3dea"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7ad1997b9bc8032603df8f091761114479285769"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7ddcf4a245c1c5a91fdd9698757e3d95179ffe41"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8bfb8414e9f2ce6f5f2f0e3d0da52f2d132128e7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b8c49ad888892ad7b77062b9c102b799a3e9b4f8"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f1acf5887c2bbaf998dc3fe32c72b7a8b84a3ddd"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: mm/huge_memory: fix folio isn't locked in softleaf_to_folio()", "id": "2460685", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2460685"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-366", "details": ["A flaw was found in the Linux kernel. A race condition exists in the memory management subsystem, specifically during transparent huge page (THP) splitting and page table entry invalidation. This can occur when a memory folio (a unit of memory) is accessed and modified without proper locking due to a missing memory barrier. This can lead to a kernel warning and potentially a system crash, resulting in a Denial of Service."], "name": "CVE-2026-31466", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-04-22T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-31466\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31466\nhttps://lore.kernel.org/linux-cve-announce/2026042253-CVE-2026-31466-4fba@gregkh/T"], "threat_severity": "Low"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e9b61f19858a5d6c42ce2298cf138279375d0d9b,426ee10711586617da869c8bb798214965337617)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e9b61f19858a5d6c42ce2298cf138279375d0d9b,f1acf5887c2bbaf998dc3fe32c72b7a8b84a3ddd)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e9b61f19858a5d6c42ce2298cf138279375d0d9b,722cfaf6b31d31123439e67b5deac6b1261a3dea)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e9b61f19858a5d6c42ce2298cf138279375d0d9b,7ddcf4a245c1c5a91fdd9698757e3d95179ffe41)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e9b61f19858a5d6c42ce2298cf138279375d0d9b,b8c49ad888892ad7b77062b9c102b799a3e9b4f8)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e9b61f19858a5d6c42ce2298cf138279375d0d9b,7ad1997b9bc8032603df8f091761114479285769)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e9b61f19858a5d6c42ce2298cf138279375d0d9b,8bfb8414e9f2ce6f5f2f0e3d0da52f2d132128e7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e9b61f19858a5d6c42ce2298cf138279375d0d9b,4c5e7f0fcd592801c9cc18f29f80fbee84eb8669)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "4.5"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,4.5)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[5.10.253,5.10.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[5.15.203,5.15.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.1.168,6.1.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.6.134,6.6.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.12.81,6.12.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.21,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.19.11,6.19.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.0,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-04-22T17:30:22.457760+00:00", "updated": "2026-04-22T17:30:22.457830+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}