bpf: Preserve pointer spill metadata during half-slot cleanup

{
  "id": "793b74a0a7d11e003313258e18f4a35c6b0c9dd31f48dc087e3a800c1f1a1cb9",
  "url": "https://osv.dev/vulnerability/CVE-2026-72426",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "bpf: Preserve pointer spill metadata during half-slot cleanup",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: bpf: Preserve pointer spill metadata during half-slot cleanup __clean_func_state() cleans dead stack slots in 4-byte halves. When the high half of a STACK_SPILL slot is dead and the low half remains live, cleanup converts the live low half to STACK_MISC or STACK_ZERO and clears the saved spilled_ptr metadata. That conversion is safe only for scalar spills. For a pointer spill, this metadata clear lets a later 32-bit fill from the still-live half avoid the normal non-scalar register-fill check and be treated as an ordinary scalar stack read. Leave non-scalar spill slots intact in this half-live shape. This is conservative for pruning and preserves the existing check_stack_read_fixed_off() rejection path for partial fills from pointer spills.",
    "evidence": "osv:CVE-2026-72426",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.1.5",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-72426",
      "aliases": [
        "CVE-2026-72426"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "be23266b4a08540aa43d8503a2ea10247c8daebe"
                },
                {
                  "fixed": "0f9278b22cda6fd2525049930157b79b4036b4ef"
                },
                {
                  "fixed": "3a354149bceacadbcf7d7b4766f5ef26a85892ab"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72426.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "7.1.0"
                },
                {
                  "fixed": "7.1.5"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72426.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:24.147876464Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0f9278b22cda6fd2525049930157b79b4036b4ef",
        "https://git.kernel.org/stable/c/3a354149bceacadbcf7d7b4766f5ef26a85892ab",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72426.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-72426",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72426.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-72426",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 490718,
  "published_at": "2026-08-15T05:56:43.575+00:00"
}