{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "7B26C1E1-97A9-48B8-81C6-B6A3A0FC6C7E",
              "versionEndExcluding": "6.18.8",
              "versionStartIncluding": "6.18",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "17B67AA7-40D6-4AFA-8459-F200F3D7CFD1",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "C47E4CC9-C826-4FA9-B014-7FE3D9B318B2",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*",
              "matchCriteriaId": "F71D92C0-C023-48BD-B3B6-70B638EEE298",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*",
              "matchCriteriaId": "13580667-0A98-40CC-B29F-D12790B91BDB",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:*",
              "matchCriteriaId": "CAD1FED7-CF48-47BF-AC7D-7B6FA3C065FC",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:*",
              "matchCriteriaId": "3EF854A1-ABB1-4E93-BE9A-44569EC76C0D",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf: Fix refcount warning on event-\u003emmap_count increment\n\nWhen calling refcount_inc(\u0026event-\u003emmap_count) inside perf_mmap_rb(), the\nfollowing warning is triggered:\n\n        refcount_t: addition on 0; use-after-free.\n        WARNING: lib/refcount.c:25\n\nPoC:\n\n    struct perf_event_attr attr = {0};\n    int fd = syscall(__NR_perf_event_open, \u0026attr, 0, -1, -1, 0);\n    mmap(NULL, 0x3000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);\n    int victim = syscall(__NR_perf_event_open, \u0026attr, 0, -1, fd,\n                         PERF_FLAG_FD_OUTPUT);\n    mmap(NULL, 0x3000, PROT_READ | PROT_WRITE, MAP_SHARED, victim, 0);\n\nThis occurs when creating a group member event with the flag\nPERF_FLAG_FD_OUTPUT. The group leader should be mmap-ed and then mmap-ing\nthe event triggers the warning.\n\nSince the event has copied the output_event in perf_event_set_output(),\nevent-\u003erb is set. As a result, perf_mmap_rb() calls\nrefcount_inc(\u0026event-\u003emmap_count) when event-\u003emmap_count = 0.\n\nDisallow the case when event-\u003emmap_count = 0. This also prevents two\nevents from updating the same user_page."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nperf: Correcci\u00f3n de la advertencia de refcount en el incremento de event-\u0026gt;mmap_count\n\nAl llamar a refcount_inc(\u0026amp;event-\u0026gt;mmap_count) dentro de perf_mmap_rb(), se activa la siguiente advertencia:\n\n        refcount_t: adici\u00f3n en 0; uso despu\u00e9s de liberaci\u00f3n.\n        ADVERTENCIA: lib/refcount.c:25\n\nPoC:\n\n    struct perf_event_attr attr = {0};\n    int fd = syscall(__NR_perf_event_open, \u0026amp;attr, 0, -1, -1, 0);\n    mmap(NULL, 0x3000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);\n    int victim = syscall(__NR_perf_event_open, \u0026amp;attr, 0, -1, fd,\n                         PERF_FLAG_FD_OUTPUT);\n    mmap(NULL, 0x3000, PROT_READ | PROT_WRITE, MAP_SHARED, victim, 0);\n\nEsto ocurre al crear un evento miembro de grupo con la bandera PERF_FLAG_FD_OUTPUT. El l\u00edder del grupo debe ser mapeado con mmap y luego mapear el evento con mmap activa la advertencia.\n\nDado que el evento ha copiado el output_event en perf_event_set_output(), event-\u0026gt;rb est\u00e1 establecido. Como resultado, perf_mmap_rb() llama a refcount_inc(\u0026amp;event-\u0026gt;mmap_count) cuando event-\u0026gt;mmap_count = 0.\n\nNo permitir el caso cuando event-\u0026gt;mmap_count = 0. Esto tambi\u00e9n evita que dos eventos actualicen la misma user_page."
    }
  ],
  "id": "CVE-2026-23127",
  "lastModified": "2026-03-18T14:49:58.400",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-02-14T15:16:07.963",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/23c0e4bd93d0b250775162faf456470485ac9fc7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/d06bf78e55d5159c1b00072e606ab924ffbbad35"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-Other"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}