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CVE-2026-98043

Estado: RecibidaSin puntuar—

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

bpf: Don't infer non-NULL from a pointer with an unbounded offset

reg_not_null() decides that a register holds a non-NULL value by looking at its type alone. For pointer types that allow arithmetic the type only guarantees a non-NULL base, in case of an unbound offset the runtime offset value might still add up to NULL. Consider the followng program:

At runtime both registers are zero, the comparison is true and the load faults with NULL pointer dereference.

Require the offset to be within +-BPF_MAX_VAR_OFF in reg_not_null().

Detalles técnicos trazas, registros y código del informe original
  r6 = bpf_map_lookup_elem(map, &0);  /* present */
  if (r6 == 0) return 0;
  r7 = bpf_map_lookup_elem(map, &1);  /* absent, NULL at runtime */
  r8 = r7;
  r8 -= r6;     /* pointer - pointer: unknown scalar, -r6 */
  r8 <<= 1;
  r8 >>= 1;     /* any non-negative offset is accepted by */
                /* check_reg_sane_offset_ptr() */
  r6 += r8;     /* verifier: map value;    runtime: zero  */
  if (r7 != r6) return 0;
  *(u8 *)(r7 + 0);  /* r7 is inferred non-NULL, both are zero */

CVSS

NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).

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)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Linux — Linux KernelAI

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-98043",
  "cveTags": [],
  "metrics": {},
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "cac616db39c207dc63465a4e05c6ce0e60b2cce4",
              "lessThan": "cb6642048739bf4ee5aa09fe465511f1e87caa63",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "cac616db39c207dc63465a4e05c6ce0e60b2cce4",
              "lessThan": "67b529f521a6676cdfc78b91b0217d7eaa84216b",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "kernel/bpf/verifier.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.8"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.8",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "kernel/bpf/verifier.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-25T11:17:33.090",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/67b529f521a6676cdfc78b91b0217d7eaa84216b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/cb6642048739bf4ee5aa09fe465511f1e87caa63",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Don't infer non-NULL from a pointer with an unbounded offset\n\nreg_not_null() decides that a register holds a non-NULL value by\nlooking at its type alone. For pointer types that allow arithmetic the\ntype only guarantees a non-NULL base, in case of an unbound offset\nthe runtime offset value might still add up to NULL.\nConsider the followng program:\n\n  r6 = bpf_map_lookup_elem(map, &0);  /* present */\n  if (r6 == 0) return 0;\n  r7 = bpf_map_lookup_elem(map, &1);  /* absent, NULL at runtime */\n  r8 = r7;\n  r8 -= r6;     /* pointer - pointer: unknown scalar, -r6 */\n  r8 <<= 1;\n  r8 >>= 1;     /* any non-negative offset is accepted by */\n                /* check_reg_sane_offset_ptr() */\n  r6 += r8;     /* verifier: map value;    runtime: zero  */\n  if (r7 != r6) return 0;\n  *(u8 *)(r7 + 0);  /* r7 is inferred non-NULL, both are zero */\n\nAt runtime both registers are zero, the comparison is true and the\nload faults with NULL pointer dereference.\n\nRequire the offset to be within +-BPF_MAX_VAR_OFF in reg_not_null()."
    }
  ],
  "lastModified": "2026-09-25T11:17:33.090",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}