CVE-2026-98376

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Use array_map_meta_equal for percpu array inner map replacement percpu_array_map_ops.map_meta_equal points to the generic bpf_map_meta_equal(), which does not compare max_entries. When a percpu array serves as an inner map, replacing it with one that has fewer max_entries bypasses the check. Since percpu_array_map_gen_lookup() inlines the original template's index_mask as a JIT immediate, a lookup on the replacement map can access pptrs[] out of bounds. Point percpu_array_map_ops.map_meta_equal to array_map_meta_equal(), which already enforces the max_entries equality check. Add a selftest to verify that replacing a percpu array inner map with a differently-sized one is rejected.

Severity

HIGH

CVSS score

7.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-09 08:16:55.910000

Last modified

2026-10-24 14:16:39.733000

View original CVE JSON

{
  "id": "CVE-2026-98376",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-09T08:16:55.910",
  "lastModified": "2026-10-24T14:16:39.733",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Use array_map_meta_equal for percpu array inner map replacement\n\npercpu_array_map_ops.map_meta_equal points to the generic\nbpf_map_meta_equal(), which does not compare max_entries.  When a\npercpu array serves as an inner map, replacing it with one that has\nfewer max_entries bypasses the check.  Since percpu_array_map_gen_lookup()\ninlines the original template's index_mask as a JIT immediate, a lookup\non the replacement map can access pptrs[] out of bounds.\n\nPoint percpu_array_map_ops.map_meta_equal to array_map_meta_equal(),\nwhich already enforces the max_entries equality check.\n\nAdd a selftest to verify that replacing a percpu array inner map with\na differently-sized one is rejected."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "kernel/bpf/arraymap.c",
            "tools/testing/selftests/bpf/prog_tests/percpu_array_inner_map.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "db69718b8efac802c7cc20d5a6c7dfc913f99c43",
              "lessThan": "593980175389a05793f6060aa20e626330960395",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "kernel/bpf/arraymap.c",
            "tools/testing/selftests/bpf/prog_tests/percpu_array_inner_map.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.10",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.10",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1",
              "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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/593980175389a05793f6060aa20e626330960395",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}