CVE-2025-40210

{
  "id": "CVE-2025-40210",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2025-11-21T11:15:49.110",
  "lastModified": "2026-10-19T19:10:00.130",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRevert \"NFSD: Remove the cap on number of operations per NFSv4 COMPOUND\"\n\nI've found that pynfs COMP6 now leaves the connection or lease in a\nstrange state, which causes CLOSE9 to hang indefinitely. I've dug\ninto it a little, but I haven't been able to root-cause it yet.\nHowever, I bisected to commit 48aab1606fa8 (\"NFSD: Remove the cap on\nnumber of operations per NFSv4 COMPOUND\").\n\nTianshuo Han also reports a potential vulnerability when decoding\nan NFSv4 COMPOUND. An attacker can place an arbitrarily large op\ncount in the COMPOUND header, which results in:\n\n[   51.410584] nfsd: vmalloc error: size 1209533382144, exceeds total\npages, mode:0xdc0(GFP_KERNEL|__GFP_ZERO),\nnodemask=(null),cpuset=/,mems_allowed=0\n\nwhen NFSD attempts to allocate the COMPOUND op array.\n\nLet's restore the operation-per-COMPOUND limit, but increased to 200\nfor now."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nRevertir 'NFSD: Remove the cap on number of operations per NFSv4 COMPOUND'\n\nHe descubierto que pynfs COMP6 ahora deja la conexión o el arrendamiento en un estado extraño, lo que provoca que CLOSE9 se cuelgue indefinidamente. He investigado un poco, pero aún no he podido determinar la causa raíz. Sin embargo, hice una búsqueda binaria hasta el commit 48aab1606fa8 ('NFSD: Remove the cap on number of operations per NFSv4 COMPOUND').\n\nTianshuo Han también informa una posible vulnerabilidad al decodificar un COMPOUND NFSv4. Un atacante puede colocar un recuento de operaciones arbitrariamente grande en la cabecera del COMPOUND, lo que resulta en:\n\n[ 51.410584] nfsd: vmalloc error: size 1209533382144, exceeds total pages, mode:0xdc0(GFP_KERNEL|__GFP_ZERO), nodemask=(null),cpuset=/,mems_allowed=0\n\ncuando NFSD intenta asignar el array de operaciones del COMPOUND.\n\nRestauremos el límite de operaciones por COMPOUND, pero aumentado a 200 por ahora."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/nfsd/nfs4proc.c",
            "fs/nfsd/nfs4state.c",
            "fs/nfsd/nfs4xdr.c",
            "fs/nfsd/nfsd.h",
            "fs/nfsd/xdr4.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "48aab1606fa80027143a445224f552b4eeea845b",
              "lessThan": "b3ee7ce432289deac87b9d14e01f2fe6958f7f0b",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "48aab1606fa80027143a445224f552b4eeea845b",
              "lessThan": "3e7f011c255582d7c914133785bbba1990441713",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "fs/nfsd/nfs4proc.c",
            "fs/nfsd/nfs4state.c",
            "fs/nfsd/nfs4xdr.c",
            "fs/nfsd/nfsd.h",
            "fs/nfsd/xdr4.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.17",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.17",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.17.8",
              "lessThanOrEqual": "6.17.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "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",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/3e7f011c255582d7c914133785bbba1990441713",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b3ee7ce432289deac87b9d14e01f2fe6958f7f0b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}