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CVE-2026-31457

Estado: AnalizadaMedia (5.5)—

In the Linux kernel, the following vulnerability has been resolved:

mm/damon/sysfs: check contexts->nr in repeat_call_fn

damon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(), damon_sysfs_upd_schemes_stats(), and damon_sysfs_upd_schemes_effective_quotas() without checking contexts->nr. If nr_contexts is set to 0 via sysfs while DAMON is running, these functions dereference contexts_arr[0] and cause a NULL pointer dereference. Add the missing check.

For example, the issue can be reproduced using DAMON sysfs interface and DAMON user-space tool (damo) [1] like below.

Detalles técnicos trazas, registros y código del informe original
    $ sudo damo start --refresh_interval 1s
    $ echo 0 | sudo tee \
            /sys/kernel/mm/damon/admin/kdamonds/0/contexts/nr_contexts

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

Mostrar
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  "id": "CVE-2026-31457",
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        "source": "nvd@nist.gov",
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          "version": "3.1",
          "baseScore": 5.5,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 1.8
      }
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  },
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          "product": "Linux",
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          ],
          "programFiles": [
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          "defaultStatus": "affected"
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  ],
  "published": "2026-04-22T14:16:41.133",
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      "tags": [
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  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/sysfs: check contexts->nr in repeat_call_fn\n\ndamon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(),\ndamon_sysfs_upd_schemes_stats(), and\ndamon_sysfs_upd_schemes_effective_quotas() without checking contexts->nr. \nIf nr_contexts is set to 0 via sysfs while DAMON is running, these\nfunctions dereference contexts_arr[0] and cause a NULL pointer\ndereference.  Add the missing check.\n\nFor example, the issue can be reproduced using DAMON sysfs interface and\nDAMON user-space tool (damo) [1] like below.\n\n    $ sudo damo start --refresh_interval 1s\n    $ echo 0 | sudo tee \\\n            /sys/kernel/mm/damon/admin/kdamonds/0/contexts/nr_contexts"
    }
  ],
  "lastModified": "2026-06-17T10:33:46.770",
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}