CVE-2025-21836 (GCVE-0-2025-21836)
Vulnerability from cvelistv5
Published
2025-03-07 09:09
Modified
2026-03-07 11:41
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: reallocate buf lists on upgrade IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it was created for legacy selected buffer and has been emptied. It violates the requirement that most of the field should stay stable after publish. Always reallocate it instead.
References
Impacted products
Vendor Product Version
Linux Linux Version: 2fcabce2d7d34f69a888146dab15b36a917f09d4
Version: 2fcabce2d7d34f69a888146dab15b36a917f09d4
Version: 2fcabce2d7d34f69a888146dab15b36a917f09d4
Version: 2fcabce2d7d34f69a888146dab15b36a917f09d4
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "io_uring/kbuf.c"
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          "vendor": "Linux",
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          "vendor": "Linux",
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              "negate": false,
              "operator": "OR"
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/kbuf: reallocate buf lists on upgrade\n\nIORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it\nwas created for legacy selected buffer and has been emptied. It violates\nthe requirement that most of the field should stay stable after publish.\nAlways reallocate it instead."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-07T11:41:55.810Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/146a185f6c05ee263db715f860620606303c4633"
        },
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          "url": "https://git.kernel.org/stable/c/7d0dc28dae836caf7645fef62a10befc624dd17b"
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        },
        {
          "url": "https://git.kernel.org/stable/c/8802766324e1f5d414a81ac43365c20142e85603"
        },
        {
          "url": "https://u1f383.github.io/slides/talks/2025_Hexacon-Deja_Vu_in_Linux_io_uring_Breaking_Memory_Sharing_Again_After_Generations_of_Fixes.pdf"
        }
      ],
      "title": "io_uring/kbuf: reallocate buf lists on upgrade",
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2025-21836",
    "datePublished": "2025-03-07T09:09:56.127Z",
    "dateReserved": "2024-12-29T08:45:45.777Z",
    "dateUpdated": "2026-03-07T11:41:55.810Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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