CVE-2026-93212 (GCVE-0-2026-93212)

Vulnerability from cvelistv5 – Published: 2026-09-24 15:10 – Updated: 2026-09-24 15:10
VLAI
Title
nfsd: guard nfsd_serv deref in nfsd_file_net_dispose
Summary
In the Linux kernel, the following vulnerability has been resolved: nfsd: guard nfsd_serv deref in nfsd_file_net_dispose nfsd_file_net_dispose() is the consumer side of l->freeme: the nfsd service thread loop calls it to drain entries that the filecache garbage collector and shrinker append via nfsd_file_dispose_list_delayed(). During per-net teardown, nn->nfsd_serv is cleared before the filecache laundrette is shut down, so the service thread can still run a dispose pass that finds more than eight entries on l->freeme and dereferences a NULL svc_serv: nfsd service thread loop nfsd_file_net_dispose(nn) if (!list_empty(&l->freeme)) { ... svc_wake_up(nn->nfsd_serv); /* nn->nfsd_serv == NULL */ } The sibling helper nfsd_file_dispose_list_delayed() already documents this ordering and caches nn->nfsd_serv into a local before testing it for NULL. nfsd_file_net_dispose() was introduced with the same raw svc_wake_up(nn->nfsd_serv) call and never picked up the guard. Fix by loading nn->nfsd_serv into a local svc_serv pointer and only calling svc_wake_up() when it is non-NULL, matching the pattern in nfsd_file_dispose_list_delayed().
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: ffb402596147ac583f3464ff5c48feb9423e3838 , < f4776c1c4b38fbc459420321c8ece87d0f7f95fb (git)
Affected: ffb402596147ac583f3464ff5c48feb9423e3838 , < 59baf45a06435194005fc5fa9a42d89f77a30432 (git)
Affected: ffb402596147ac583f3464ff5c48feb9423e3838 , < 766170b4fd2daaf5c4d6735560101474e18edab6 (git)
Affected: ffb402596147ac583f3464ff5c48feb9423e3838 , < 9f1ddfc8cb9076592401a611eb3a44d36186d014 (git)
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Linux Linux Affected: 6.9
Unaffected: 0 , < 6.9 (semver)
Unaffected: 6.12.109 , ≤ 6.12.* (semver)
Unaffected: 6.18.50 , ≤ 6.18.* (semver)
Unaffected: 7.2.4 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
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{
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          "product": "Linux",
          "programFiles": [
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: guard nfsd_serv deref in nfsd_file_net_dispose\n\nnfsd_file_net_dispose() is the consumer side of l-\u003efreeme: the nfsd\nservice thread loop calls it to drain entries that the filecache\ngarbage collector and shrinker append via\nnfsd_file_dispose_list_delayed().  During per-net teardown,\nnn-\u003enfsd_serv is cleared before the filecache laundrette is shut\ndown, so the service thread can still run a dispose pass that finds\nmore than eight entries on l-\u003efreeme and dereferences a NULL\nsvc_serv:\n\n    nfsd service thread loop\n      nfsd_file_net_dispose(nn)\n        if (!list_empty(\u0026l-\u003efreeme)) {\n            ...\n            svc_wake_up(nn-\u003enfsd_serv);   /* nn-\u003enfsd_serv == NULL */\n        }\n\nThe sibling helper nfsd_file_dispose_list_delayed() already documents\nthis ordering and caches nn-\u003enfsd_serv into a local before testing it\nfor NULL.  nfsd_file_net_dispose() was introduced with the same raw\nsvc_wake_up(nn-\u003enfsd_serv) call and never picked up the guard.\n\nFix by loading nn-\u003enfsd_serv into a local svc_serv pointer and only\ncalling svc_wake_up() when it is non-NULL, matching the pattern in\nnfsd_file_dispose_list_delayed()."
        }
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        "dateUpdated": "2026-09-24T15:10:35.280Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/9f1ddfc8cb9076592401a611eb3a44d36186d014"
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      ],
      "title": "nfsd: guard nfsd_serv deref in nfsd_file_net_dispose",
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    "cveId": "CVE-2026-93212",
    "datePublished": "2026-09-24T15:10:35.280Z",
    "dateReserved": "2026-09-17T16:02:15.093Z",
    "dateUpdated": "2026-09-24T15:10:35.280Z",
    "state": "PUBLISHED"
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            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: guard nfsd_serv deref in nfsd_file_net_dispose\n\nnfsd_file_net_dispose() is the consumer side of l-\u003efreeme: the nfsd\nservice thread loop calls it to drain entries that the filecache\ngarbage collector and shrinker append via\nnfsd_file_dispose_list_delayed().  During per-net teardown,\nnn-\u003enfsd_serv is cleared before the filecache laundrette is shut\ndown, so the service thread can still run a dispose pass that finds\nmore than eight entries on l-\u003efreeme and dereferences a NULL\nsvc_serv:\n\n    nfsd service thread loop\n      nfsd_file_net_dispose(nn)\n        if (!list_empty(\u0026l-\u003efreeme)) {\n            ...\n            svc_wake_up(nn-\u003enfsd_serv);   /* nn-\u003enfsd_serv == NULL */\n        }\n\nThe sibling helper nfsd_file_dispose_list_delayed() already documents\nthis ordering and caches nn-\u003enfsd_serv into a local before testing it\nfor NULL.  nfsd_file_net_dispose() was introduced with the same raw\nsvc_wake_up(nn-\u003enfsd_serv) call and never picked up the guard.\n\nFix by loading nn-\u003enfsd_serv into a local svc_serv pointer and only\ncalling svc_wake_up() when it is non-NULL, matching the pattern in\nnfsd_file_dispose_list_delayed()."
          }
        ],
        "id": "CVE-2026-93212",
        "lastModified": "2026-09-24T16:17:16.133",
        "metrics": {},
        "published": "2026-09-24T16:17:16.133",
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      "cve": "CVE-2026-93212",
      "id": "CVE-2026-93212",
      "initial_release_date": "2026-09-24T23:50:00Z",
      "product_status:known_affected": "162",
      "product_status:known_not_affected": "185",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-93212",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-93212.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.