{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-53399",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-53399"
  ],
  "published": "2026-07-19T12:02:32Z",
  "summary": "nfsd: release layout stid on setlease failure",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: release layout stid on setlease failure\n\nnfs4_alloc_stid() publishes the new stid into cl->cl_stateids via\nidr_alloc_cyclic() under cl_lock before returning to\nnfsd4_alloc_layout_stateid(). When nfsd4_layout_setlease() then\nfails, the error path frees the layout stateid directly with\nkmem_cache_free() without ever calling idr_remove(), leaving the\nIDR slot pointing at freed slab memory. Any subsequent IDR walker\n(states_show, client teardown) dereferences the dangling pointer.\n\nThe correct teardown for an IDR-published stid is nfs4_put_stid(),\nwhich removes the IDR slot under cl_lock, dispatches sc_free\n(nfsd4_free_layout_stateid) to release ls->ls_file via\nnfsd4_close_layout(), and drops the nfs4_file reference in its\ntail.\n\nA second issue blocks that switch: nfsd4_free_layout_stateid()\nunconditionally inspects ls->ls_fence_work via\ndelayed_work_pending() under ls_lock, but\nINIT_DELAYED_WORK(&ls->ls_fence_work, ...) currently runs only\nafter the setlease call. On the setlease-failure path the\ndestructor would touch an uninitialized delayed_work.\n\n    nfsd4_alloc_layout_stateid()\n      nfs4_alloc_stid()           /* idr_alloc_cyclic under cl_lock */\n      nfsd4_layout_setlease()     /* fails */\n        nfs4_put_stid()\n          nfsd4_free_layout_stateid()\n            delayed_work_pending(&ls->ls_fence_work)  /* needs INIT */\n            nfsd4_close_layout()  /* nfsd_file_put(ls->ls_file) */\n          put_nfs4_file()\n\nFix by hoisting the ls_fenced / ls_fence_delay / INIT_DELAYED_WORK\ninitialization above the nfsd4_layout_setlease() call, and replace\nthe manual nfsd_file_put + put_nfs4_file + kmem_cache_free cleanup\nwith a single nfs4_put_stid(stp).",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.178",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-53399"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d788ef40a7517d22c97ab01700e4ae4c611b6f2f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2e0a5d6d62600b8c614d1b55e50ef94035d6adf9"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/7bbb7ce74051c8be4b69ff44ce3db370600dae61"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/48a586e382e4db1dbf958d44b63e081df5f8ed04"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d369e5edfaaf83a448016e2f1da392b2174be801"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8dee7c278f1c2b5bb80e17a6281c3812fc8b0cdd"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/83c2b7797742339bb768f83935f7ca33950db138"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/30d55c8aabb261bc3f427d6b9aae7ef6206063f9"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-17T05:24:08Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 9.8,
      "cvss_v3_severity": "Critical",
      "scenario": "AV:N - The bug is reached through nfsd's NFSv4 OP_LAYOUTGET handler, which processes attacker-controlled RPC compounds over the network on TCP port 2049.\nAC:L - An authenticated NFS client can reliably trigger the fault by issuing LAYOUTGET on block/SCSI pNFS exports so that nfsd4_layout_setlease() fails (e.g., -ENOMEM or -EINVAL), and can retry, spray the slab, and race concurrent compounds to exploit the dangling IDR entry.\nPR:N - Exploitation requires only the ability to act as a remote NFSv4 client against an export with pNFS enabled, not local shell access or elevated privileges on the Linux host.\nUI:N - No end-user or administrator action on the server is required; the vulnerability is triggered entirely through malicious NFS protocol traffic from a network client.\nS:U - Impact is confined to kernel memory corruption and nfsd state within the same kernel security boundary, not a cross-boundary escape such as VM or container breakout.\nC:H - The IDR retains a pointer to freed layout stateid slab memory, creating a use-after-free that can be leveraged for arbitrary kernel memory reads after heap reuse.\nI:H - UAF on the layout stateid object enables controlled slab reuse and corruption of adjacent kernel structures, supporting arbitrary write or control-flow hijack primitives.\nA:H - Dereferencing the dangling IDR pointer during state iteration or stateid lookup can cause kernel oops/panic, and UAF exploitation can crash or hang the server."
    }
  }
}