{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "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",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "593980175389a05793f6060aa20e626330960395",
              "status": "affected",
              "version": "db69718b8efac802c7cc20d5a6c7dfc913f99c43",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "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",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.10"
            },
            {
              "lessThan": "6.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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\u0027s 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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The local bpf(BPF_MAP_UPDATE_ELEM) path reaches map_update_elem()-\u003ebpf_map_update_value()-\u003ebpf_fd_array_map_update_elem()-\u003ebpf_map_fd_get_ptr(), where the patched percpu_array_map_ops.map_meta_equal validates the replacement map; no network handler supplies its FD or dimensions.\nAC:L - The attacker chooses the template and replacement max_entries, lookup key, program, and trigger; an index below the template limit but beyond the replacement deterministically reads pptrs[] out of bounds. No race or other actor is required on a JIT-enabled x86-64 or arm64 target.\nPR:L - map_create() places PERCPU_ARRAY and ARRAY_OF_MAPS in its unprivileged branch, and bpf_prog_load() permits SOCKET_FILTER without CAP_BPF when unprivileged BPF is enabled; alternatively, a user-namespace BPF token satisfies the gates without init-namespace root.\nUI:N - The attacker creates and replaces the maps, loads the lookup program, attaches it through SO_ATTACH_BPF to their own socket, and sends the triggering data themselves; no victim action is needed.\nS:U - percpu_array_map_gen_lookup() converts the out-of-bounds pptrs[] slot into a pointer used against the same host kernel\u0027s memory; this is ordinary kernel privilege escalation, not a guest-to-host, IOMMU, or other security-authority crossing.\nC:H - percpu_array_map_gen_lookup() loads a 64-bit pptrs[index] out of bounds and returns its adjusted value as a verifier-trusted map-value pointer. Because bpf_map_area_alloc() kmallocs the flexible object, map spraying can place chosen bytes at that slot, enabling kernel reads copied into another map.\nI:H - The forged PTR_TO_MAP_VALUE is writable because default map flags grant BPF_MAP_CAN_WRITE; direct BPF stores through an attacker-groomed out-of-bounds pptrs[] value therefore provide an arbitrary kernel-write primitive suitable for control-flow hijacking.\nA:H - Without successful grooming, BPF_MOV64_PERCPU_REG adjusts the garbage pointer loaded beyond pptrs[] and the attacker\u0027s next value access dereferences it, causing a kernel oops or panic; the attacker can repeatedly run the same socket-filter program."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-24T14:08:36.004Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/593980175389a05793f6060aa20e626330960395"
        }
      ],
      "title": "bpf: Use array_map_meta_equal for percpu array inner map replacement",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98376",
    "datePublished": "2026-10-09T07:34:17.043Z",
    "dateReserved": "2026-09-25T10:25:14.345Z",
    "dateUpdated": "2026-10-24T14:08:36.004Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}