NFSD: Hold net reference for the lifetime of /proc/fs/nfs/exports fd_CVE-2026-31403

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Hold net reference for the lifetime of /proc/fs/nfs/exports fd\n\nThe /proc/fs/nfs/exports proc entry is created at module init\nand persists for the module's lifetime. exports_proc_open()\ncaptures the caller's current network namespace and stores\nits svc_export_cache in seq->private, but takes no reference\non the namespace. If the namespace is subsequently torn down\n(e.g. container destruction after the opener does setns() to a\ndifferent namespace), nfsd_net_exit() calls nfsd_export_shutdown()\nwhich frees the cache. Subsequent reads on the still-open fd\ndereference the freed cache_detail, walking a freed hash table.\n\nHold a reference on the struct net for the lifetime of the open\nfile descriptor. This prevents nfsd_net_exit() from running --\nand thus prevents nfsd_export_shutdown() from freeing the cache\n-- while any exports fd is open. cache_detail already stores\nits net pointer (cd->net, set by cache_create_net()), so\nexports_release() can retrieve it without additional per-file\nstorage.",
    "published": "2026-04-03T15:16:06.444Z",
    "modified": "2026-04-27T14:02:50.491Z",
    "type": "cve",
    "title": "NFSD: Hold net reference for the lifetime of /proc/fs/nfs/exports fd",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/76740c28050dc6db2f5550f1325b00a11bbb3255\nhttps://git.kernel.org/stable/c/c7f406fb341d6747634b8b1fa5461656e5e56076\nhttps://git.kernel.org/stable/c/d1a19217995df9c7e4118f5a2820c5032fef2945\nhttps://git.kernel.org/stable/c/e3d77f935639e6ae4b381c80464c31df998d61f4\nhttps://git.kernel.org/stable/c/db4a9f99b12a7ee1c19d86c83a3b752c7effa6c6\nhttps://git.kernel.org/stable/c/6a8d70e2ad6aad2c345a5048edcb8168036f97d6\nhttps://git.kernel.org/stable/c/e7fcf179b82d3a3730fd8615da01b087cc654d0b",
    "id": "CVE-2026-31403",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux 96d851c4d28de8cc83fe2bd5c6bc2eb8f253a6c5\nLinux Linux 96d851c4d28de8cc83fe2bd5c6bc2eb8f253a6c5\nLinux Linux 96d851c4d28de8cc83fe2bd5c6bc2eb8f253a6c5\nLinux Linux 96d851c4d28de8cc83fe2bd5c6bc2eb8f253a6c5\nLinux Linux 96d851c4d28de8cc83fe2bd5c6bc2eb8f253a6c5\nLinux Linux 96d851c4d28de8cc83fe2bd5c6bc2eb8f253a6c5\nLinux Linux 96d851c4d28de8cc83fe2bd5c6bc2eb8f253a6c5\nLinux Linux 3.9",
    "sourceHref": "",
    "cvss": {
        "score": 7.8,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
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        "baseScore": 0,
        "baseSeverity": "",
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        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
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            "baseScore": 0,
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "96d851c4d28de8cc83fe2bd5c6bc2eb8f253a6c5",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
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    "ai_score": 0
}