{
  "id": "CVE-2025-21857",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2025-03-12T10:15:18.583",
  "lastModified": "2025-03-13T21:15:46.950",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_api: fix error handling causing NULL dereference\n\ntcf_exts_miss_cookie_base_alloc() calls xa_alloc_cyclic() which can\nreturn 1 if the allocation succeeded after wrapping. This was treated as\nan error, with value 1 returned to caller tcf_exts_init_ex() which sets\nexts->actions to NULL and returns 1 to caller fl_change().\n\nfl_change() treats err == 1 as success, calling tcf_exts_validate_ex()\nwhich calls tcf_action_init() with exts->actions as argument, where it\nis dereferenced.\n\nExample trace:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000000\nCPU: 114 PID: 16151 Comm: handler114 Kdump: loaded Not tainted 5.14.0-503.16.1.el9_5.x86_64 #1\nRIP: 0010:tcf_action_init+0x1f8/0x2c0\nCall Trace:\n tcf_action_init+0x1f8/0x2c0\n tcf_exts_validate_ex+0x175/0x190\n fl_change+0x537/0x1120 [cls_flower]"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net/sched: cls_api: se corrige el error de gesti\u00f3n que causa la desreferencia de NULL. tcf_exts_miss_cookie_base_alloc() llama a xa_alloc_cyclic(), que puede devolver 1 si la asignaci\u00f3n se realiz\u00f3 correctamente tras el encapsulado. Esto se trat\u00f3 como un error, con el valor 1 devuelto al llamador tcf_exts_init_ex(), que establece exts->actions en NULL y devuelve 1 al llamador fl_change(). fl_change() trata err == 1 como correcto, llamando a tcf_exts_validate_ex(), que llama a tcf_action_init() con exts->actions como argumento, donde se desreferencia. Ejemplo de seguimiento: ERROR: desreferencia de puntero NULL del n\u00facleo, direcci\u00f3n: 0000000000000000 CPU: 114 PID: 16151 Comm: handler114 Kdump: cargado No contaminado 5.14.0-503.16.1.el9_5.x86_64 #1 RIP: 0010:tcf_action_init+0x1f8/0x2c0 Seguimiento de llamadas: tcf_action_init+0x1f8/0x2c0 tcf_exts_validate_ex+0x175/0x190 fl_change+0x537/0x1120 [cls_flower]"
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "nvd@nist.gov",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6
      }
    ]
  },
  "weaknesses": [
    {
      "source": "nvd@nist.gov",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.3",
              "versionEndExcluding": "6.6.80",
              "matchCriteriaId": "ACF3631C-19E5-4953-B4A3-AB7CD48E6A57"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.7",
              "versionEndExcluding": "6.12.17",
              "matchCriteriaId": "15370AEE-6D1C-49C3-8CB7-E889D5F92B6F"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.13",
              "versionEndExcluding": "6.13.5",
              "matchCriteriaId": "72E69ABB-9015-43A6-87E1-5150383CFFD9"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "186716B6-2B66-4BD0-852E-D48E71C0C85F"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "0D3E781C-403A-498F-9DA9-ECEE50F41E75"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*",
              "matchCriteriaId": "66619FB8-0AAF-4166-B2CF-67B24143261D"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/071ed42cff4fcdd89025d966d48eabef59913bf2",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/3c74b5787caf59bb1e9c5fe0a360643a71eb1e8a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/3e4c56cf41876ef2a82f0877fe2a67648f8632b8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://git.kernel.org/stable/c/de4b679aa3b4da7ec34f639df068b914f20e3c3c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ]
    }
  ]
}