{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-64514",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-07-19T15:36:31.793Z",
        "datePublished": "2026-07-25T08:52:05.878Z",
        "dateUpdated": "2026-08-17T04:57:05.592Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-17T04:57:05.592Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nuserfaultfd: gate must_wait writability check on pte_present()\n\nuserfaultfd_must_wait() and userfaultfd_huge_must_wait() read the PTE\nwithout taking the page table lock and then apply pte_write() /\nhuge_pte_write() to it.  Those accessors decode bits from the present\nencoding only; on a swap or migration entry they read the offset bits that\nhappen to share the same position and return an undefined result.\n\nThe intent of the check is \"is this fault still WP-blocked?\".  A\nnon-marker swap entry means the page is in transit -- the userfault\ncontext the original fault delivered against is no longer the same, and\nthe swap-in or migration completion path will re-deliver a fresh fault if\nuserspace still needs to handle it.  Worst case under the current code the\ngarbage write bit says \"wait\", and the thread stays asleep until a\nUFFDIO_WAKE that may never arrive.\n\nGate the writability check on pte_present() so the lockless re-check only\ninspects present-PTE bits when the entry is actually present.  The\nnon-present, non-marker case returns \"don't wait\" and lets the fault path\nretry."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "mm/userfaultfd.c"
                    ],
                    "versions": [
                        {
                            "version": "369cd2121be440543280b91056de187f625d0dbb",
                            "lessThan": "a5700a4c1c9099ac2ac73fe8a09cf059972e0d2f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "369cd2121be440543280b91056de187f625d0dbb",
                            "lessThan": "d4026417e8184d13850a0bad4d96ceb6ed9f7152",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "369cd2121be440543280b91056de187f625d0dbb",
                            "lessThan": "29e6f952c5fb7dc1d6b90fe5b7f36063d44ddae0",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "369cd2121be440543280b91056de187f625d0dbb",
                            "lessThan": "5f4dbdb0a87596214076b20b94f2b71b522170b3",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "369cd2121be440543280b91056de187f625d0dbb",
                            "lessThan": "a6e9a4939e359599701b1da351e84f72e021443a",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "369cd2121be440543280b91056de187f625d0dbb",
                            "lessThan": "60d696a037eeeedfb57756dfe7ec08a1587c8631",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "369cd2121be440543280b91056de187f625d0dbb",
                            "lessThan": "710183888174639a15fcec16cd1af766b8480bb7",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "369cd2121be440543280b91056de187f625d0dbb",
                            "lessThan": "8e80af52db652fbc41320eee45a4f73bc029faf2",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "mm/userfaultfd.c"
                    ],
                    "versions": [
                        {
                            "version": "4.11",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "4.11",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.10.261",
                            "lessThanOrEqual": "5.10.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.212",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.178",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.145",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.96",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.39",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.4",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2",
                            "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": "4.11",
                                    "versionEndExcluding": "5.10.261"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.11",
                                    "versionEndExcluding": "5.15.212"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.11",
                                    "versionEndExcluding": "6.1.178"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.11",
                                    "versionEndExcluding": "6.6.145"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.11",
                                    "versionEndExcluding": "6.12.96"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.11",
                                    "versionEndExcluding": "6.18.39"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.11",
                                    "versionEndExcluding": "7.1.4"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.11",
                                    "versionEndExcluding": "7.2"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/a5700a4c1c9099ac2ac73fe8a09cf059972e0d2f"
                },
                {
                    "url": "https://git.kernel.org/stable/c/d4026417e8184d13850a0bad4d96ceb6ed9f7152"
                },
                {
                    "url": "https://git.kernel.org/stable/c/29e6f952c5fb7dc1d6b90fe5b7f36063d44ddae0"
                },
                {
                    "url": "https://git.kernel.org/stable/c/5f4dbdb0a87596214076b20b94f2b71b522170b3"
                },
                {
                    "url": "https://git.kernel.org/stable/c/a6e9a4939e359599701b1da351e84f72e021443a"
                },
                {
                    "url": "https://git.kernel.org/stable/c/60d696a037eeeedfb57756dfe7ec08a1587c8631"
                },
                {
                    "url": "https://git.kernel.org/stable/c/710183888174639a15fcec16cd1af766b8480bb7"
                },
                {
                    "url": "https://git.kernel.org/stable/c/8e80af52db652fbc41320eee45a4f73bc029faf2"
                }
            ],
            "title": "userfaultfd: gate must_wait writability check on pte_present()",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}