io_uring: fix regbuf vector size truncation

{
  "id": "8ca421ee2931f47a125b38d8c693373d3928154fea237873badf013734bb8307",
  "url": "https://osv.dev/vulnerability/CVE-2025-40291",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "io_uring: fix regbuf vector size truncation",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: io_uring: fix regbuf vector size truncation There is a report of io_estimate_bvec_size() truncating the calculated number of segments that leads to corruption issues. Check it doesn't overflow \"int\"s used later. Rough but simple, can be improved on top.",
    "evidence": "osv:CVE-2025-40291",
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              "type": "ECOSYSTEM",
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          "package": {
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            "ecosystem": "Linux"
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      "modified": "2026-10-28T02:30:26.866558120Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/146eb58629f45f8297e83d69e64d4eea4b28d972",
        "https://git.kernel.org/stable/c/826ce37a842633efe1bb763e4b13045d74060d72",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/40xxx/CVE-2025-40291.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-40291",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
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        "value": "CVE-2025-40291",
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    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
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  "source_id": "core-osv",
  "document_id": 493134,
  "published_at": "2025-12-08T00:46:14.601+00:00"
}