{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2025-71090",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-01-13T15:30:19.649Z",
        "datePublished": "2026-01-13T15:34:51.777Z",
        "dateUpdated": "2026-08-05T12:11:59.817Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:11:59.817Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix nfsd_file reference leak in nfsd4_add_rdaccess_to_wrdeleg()\n\nnfsd4_add_rdaccess_to_wrdeleg() unconditionally overwrites\nfp->fi_fds[O_RDONLY] with a newly acquired nfsd_file. However, if\nthe client already has a SHARE_ACCESS_READ open from a previous OPEN\noperation, this action overwrites the existing pointer without\nreleasing its reference, orphaning the previous reference.\n\nAdditionally, the function originally stored the same nfsd_file\npointer in both fp->fi_fds[O_RDONLY] and fp->fi_rdeleg_file with\nonly a single reference. When put_deleg_file() runs, it clears\nfi_rdeleg_file and calls nfs4_file_put_access() to release the file.\n\nHowever, nfs4_file_put_access() only releases fi_fds[O_RDONLY] when\nthe fi_access[O_RDONLY] counter drops to zero. If another READ open\nexists on the file, the counter remains elevated and the nfsd_file\nreference from the delegation is never released. This potentially\ncauses open conflicts on that file.\n\nThen, on server shutdown, these leaks cause __nfsd_file_cache_purge()\nto encounter files with an elevated reference count that cannot be\ncleaned up, ultimately triggering a BUG() in kmem_cache_destroy()\nbecause there are still nfsd_file objects allocated in that cache."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                        "baseScore": 7.5,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:N - The vulnerable path processes remotely supplied NFSv4.1 COMPOUND OPEN requests through the kernel NFS server. An attacker can trigger it over the network against an exposed NFS export.\nAC:L - The attacker can deterministically retain a READ open using WANT_NO_DELEG and then request an uncontended WRITE-only open that receives a write delegation. No race or condition outside the attacker's control is required.\nPR:N - A permissive read-write export using AUTH_SYS or AUTH_NULL can allow an unauthenticated client to establish a session and open an anonymous or world-accessible file. No pre-existing target-system privileges are required in this reasonable deployment.\nUI:N - The malicious client alone can issue the OPEN, DELEGRETURN, and CLOSE operations needed to create repeatable leaks. No victim user action is required.\nS:U - The leak and resulting denial of service remain within the NFS server and host kernel security authority. No virtualization, sandbox, or other security boundary is crossed.\nC:N - The bug retains valid nfsd_file objects and does not free, over-read, or expose their contents. It provides no memory-disclosure primitive.\nI:N - The overwritten pointer causes an orphaned reference rather than a dangling pointer or memory corruption. It provides no arbitrary write, control-flow hijack, or data-modification primitive.\nA:H - The leak can be repeated across attacker-accessible files, retaining file-cache objects and causing resource exhaustion or open conflicts. During final nfsd cache teardown, the remaining objects trigger the slab BUG/WARN path and can panic systems configured to treat warnings as fatal."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/nfsd/nfs4state.c"
                    ],
                    "versions": [
                        {
                            "version": "e7a8ebc305f26cab608e59a916a4ae89d6656c5f",
                            "lessThan": "c07dc84ed67c5a182273171639bacbbb87c12175",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "e7a8ebc305f26cab608e59a916a4ae89d6656c5f",
                            "lessThan": "8072e34e1387d03102b788677d491e2bcceef6f5",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/nfsd/nfs4state.c"
                    ],
                    "versions": [
                        {
                            "version": "6.17",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.17",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.4",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.19",
                            "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": "6.17",
                                    "versionEndExcluding": "6.18.4"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.17",
                                    "versionEndExcluding": "6.19"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/c07dc84ed67c5a182273171639bacbbb87c12175"
                },
                {
                    "url": "https://git.kernel.org/stable/c/8072e34e1387d03102b788677d491e2bcceef6f5"
                }
            ],
            "title": "nfsd: fix nfsd_file reference leak in nfsd4_add_rdaccess_to_wrdeleg()",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}