io_uring/zcrx: fix overshooting recv limit

{
  "id": "196655b5597eb80177aa3842830d96467705c12cc39df6b8fbfe89c9e7de05c7",
  "url": "https://osv.dev/vulnerability/CVE-2025-40046",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "io_uring/zcrx: fix overshooting recv limit",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: io_uring/zcrx: fix overshooting recv limit It's reported that sometimes a zcrx request can receive more than was requested. It's caused by io_zcrx_recv_skb() adjusting desc->count for all received buffers including frag lists, but then doing recursive calls to process frag list skbs, which leads to desc->count double accounting and underflow.",
    "evidence": "osv:CVE-2025-40046",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.17.3",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2025-40046",
      "aliases": [
        "CVE-2025-40046"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "6699ec9a23f85f1764183430209c741847c45f12"
                },
                {
                  "fixed": "8bcc9eaf1b19f1a7029cba19f6bd4122b40f6c4f"
                },
                {
                  "fixed": "09cfd3c52ea76f43b3cb15e570aeddf633d65e80"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-40046.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.15.0"
                },
                {
                  "fixed": "6.17.3"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-40046.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:29.369337335Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/09cfd3c52ea76f43b3cb15e570aeddf633d65e80",
        "https://git.kernel.org/stable/c/8bcc9eaf1b19f1a7029cba19f6bd4122b40f6c4f",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40046.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-40046",
        "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/2025/40xxx/CVE-2025-40046.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-40046",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 496355,
  "published_at": "2025-10-28T11:48:24.022+00:00"
}