net/mlx5e: Prevent stale XSK buffer release on refill retry

{
  "id": "feba7f90732620d3148aac2a74ba17ec4df737b82fe0d6c0391c6c2ea8f04add",
  "url": "https://osv.dev/vulnerability/CVE-2026-99079",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net/mlx5e: Prevent stale XSK buffer release on refill retry",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Prevent stale XSK buffer release on refill retry When an XDP redirect to an AF_XDP socket fails because its RX ring is full, the XSK core frees the buffer. During the subsequent batched refill of a legacy cyclic RQ, mlx5e also releases the WQE's XSK buffer before allocating a replacement. If that refill succeeds only partially, a WQE left without a replacement retains its old buffer pointer. The buffer can meanwhile be allocated to another WQE. A later refill retry can then free the live buffer through the stale pointer and publish the same UMEM frame twice. Mark the WQE as released immediately after the driver-side free. The flag is already cleared when a replacement buffer is assigned, so refill retries no longer release stale pointers. The failure is silent and produces no kernel warning or splat. A standalone legacy cyclic-RQ zero-copy libxsk reproducer, using 64-byte UDP traffic offered at 12 Mpps, detected it: stock stopped after 2,854,914 packets in 4.094 seconds, with 4,542 xdp_rx_ring_full events and 64 ownership/double-publication errors. With this change it processed 356,904,225 packets in 30 seconds despite 571,405 xdp_rx_ring_full events, with no ownership or data errors.",
    "evidence": "osv:CVE-2026-99079",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.6.160",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.113",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.57",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.11",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-99079",
      "aliases": [
        "CVE-2026-99079"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/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": [
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                  "introduced": "3f93f82988bc6b4104314bf9aa485d47fbb7e241"
                },
                {
                  "fixed": "32bbb870078d467479965c21bbc4960c57eea208"
                },
                {
                  "fixed": "34d1db2b18e1c1d189e34dd51923e031815f88e3"
                },
                {
                  "fixed": "639522e5056cade578a324acfa993ec6c9f7f5dc"
                },
                {
                  "fixed": "655f47477054d19de3b138840be229a1a4490d0c"
                },
                {
                  "fixed": "e01620844c5c88b6fcf819d171df8e3976a0e76f"
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              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-99079.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.4.0"
                },
                {
                  "fixed": "6.6.160"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.7.0"
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                  "fixed": "6.12.113"
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              "events": [
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                  "introduced": "6.13.0"
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                {
                  "fixed": "6.18.57"
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            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.11"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-99079.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:48.789787154Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/32bbb870078d467479965c21bbc4960c57eea208",
        "https://git.kernel.org/stable/c/34d1db2b18e1c1d189e34dd51923e031815f88e3",
        "https://git.kernel.org/stable/c/639522e5056cade578a324acfa993ec6c9f7f5dc",
        "https://git.kernel.org/stable/c/655f47477054d19de3b138840be229a1a4490d0c",
        "https://git.kernel.org/stable/c/e01620844c5c88b6fcf819d171df8e3976a0e76f",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99079.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-99079",
        "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/2026/99xxx/CVE-2026-99079.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-99079",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 517160,
  "published_at": "2026-10-23T12:23:26.458+00:00"
}