CVE-2026-45983 (GCVE-0-2026-45983)
Vulnerability from cvelistv5
Published
2026-05-27 12:18
Modified
2026-05-27 12:18
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: nfsd: never defer requests during idmap lookup During v4 request compound arg decoding, some ops (e.g. SETATTR) can trigger idmap lookup upcalls. When those upcall responses get delayed beyond the allowed time limit, cache_check() will mark the request for deferral and cause it to be dropped. This prevents nfs4svc_encode_compoundres from being executed, and thus the session slot flag NFSD4_SLOT_INUSE never gets cleared. Subsequent client requests will fail with NFSERR_JUKEBOX, given that the slot will be marked as in-use, making the SEQUENCE op fail. Fix this by making sure that the RQ_USEDEFERRAL flag is always clear during nfs4svc_decode_compoundargs(), since no v4 request should ever be deferred.
References
Impacted products
Vendor Product Version
Linux Linux Version: 2f425878b6a71571341dcd3f9e9d1a6f6355da9c
Version: 2f425878b6a71571341dcd3f9e9d1a6f6355da9c
Version: 2f425878b6a71571341dcd3f9e9d1a6f6355da9c
Version: 2f425878b6a71571341dcd3f9e9d1a6f6355da9c
Version: 2f425878b6a71571341dcd3f9e9d1a6f6355da9c
Version: 2f425878b6a71571341dcd3f9e9d1a6f6355da9c
Version: 2f425878b6a71571341dcd3f9e9d1a6f6355da9c
Version: 2f425878b6a71571341dcd3f9e9d1a6f6355da9c
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{
  "containers": {
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          "programFiles": [
            "fs/nfsd/nfs4idmap.c",
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              "negate": false,
              "operator": "OR"
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: never defer requests during idmap lookup\n\nDuring v4 request compound arg decoding, some ops (e.g. SETATTR)\ncan trigger idmap lookup upcalls. When those upcall responses get\ndelayed beyond the allowed time limit, cache_check() will mark the\nrequest for deferral and cause it to be dropped.\n\nThis prevents nfs4svc_encode_compoundres from being executed, and\nthus the session slot flag NFSD4_SLOT_INUSE never gets cleared.\nSubsequent client requests will fail with NFSERR_JUKEBOX, given\nthat the slot will be marked as in-use, making the SEQUENCE op\nfail.\n\nFix this by making sure that the RQ_USEDEFERRAL flag is always\nclear during nfs4svc_decode_compoundargs(), since no v4 request\nshould ever be deferred."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-27T12:18:41.619Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b9abb760db20504240a7147f27934d900cd80b23"
        },
        {
          "url": "https://git.kernel.org/stable/c/3a72c7dedc99b321e0f267e4e999e5baf07c4593"
        },
        {
          "url": "https://git.kernel.org/stable/c/99e17b20fddac19a228d213e00f6b9e1c10daff9"
        },
        {
          "url": "https://git.kernel.org/stable/c/243f71ed873ff3feeb6f9b5cb145d63f7188b4c4"
        },
        {
          "url": "https://git.kernel.org/stable/c/063a6f22478ef929625000a2caf54667725c1dfd"
        },
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          "url": "https://git.kernel.org/stable/c/d75ec4504a4340b033b15cad0303988b3089dd93"
        },
        {
          "url": "https://git.kernel.org/stable/c/8dff54fe88c0dcd4c55bff9fc2fa6ca968290826"
        },
        {
          "url": "https://git.kernel.org/stable/c/f9c206cdc4266caad6a9a7f46341420a10f03ccb"
        }
      ],
      "title": "nfsd: never defer requests during idmap lookup",
      "x_generator": {
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  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-45983",
    "datePublished": "2026-05-27T12:18:41.619Z",
    "dateReserved": "2026-05-13T15:03:33.090Z",
    "dateUpdated": "2026-05-27T12:18:41.619Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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