net/mlx5: free mlx5_st_idx_data on final dealloc

{
  "id": "9d3ebc67d02fffc9b4feefa43a9f48d2add9c53e0319cd80308825c83117e8cc",
  "url": "https://osv.dev/vulnerability/CVE-2026-72006",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net/mlx5: free mlx5_st_idx_data on final dealloc",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net/mlx5: free mlx5_st_idx_data on final dealloc Workloads that repeatedly allocate and release mkeys carrying TPH steering-tag hints (e.g. churning RDMA MRs) leak one struct mlx5_st_idx_data per cycle; kmemleak flags it as unreferenced and the kmalloc slab grows over time. When the last reference to an ST table entry is dropped, mlx5_st_dealloc_index() removed the entry from idx_xa but the backing mlx5_st_idx_data allocation was never freed. Free idx_data after the xa_erase() so the lifetime of the bookkeeping struct matches the lifetime of the ST entry it tracks.",
    "evidence": "osv:CVE-2026-72006",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.40",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.5",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-72006",
      "aliases": [
        "CVE-2026-72006"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "888a7776f4fb04c19bec70c737c61c2f383c6b1e"
                },
                {
                  "fixed": "262da8b6ea03d01ee7ed01ad309e4c89941f6b14"
                },
                {
                  "fixed": "6eb4cf2fa8997f62c11e0006dc010a1fd89c5a75"
                },
                {
                  "fixed": "df6134b527a88b3e65ba6ae5073664af091d5fd2"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72006.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.17.0"
                },
                {
                  "fixed": "6.18.40"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.1.5"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72006.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.062873888Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/262da8b6ea03d01ee7ed01ad309e4c89941f6b14",
        "https://git.kernel.org/stable/c/6eb4cf2fa8997f62c11e0006dc010a1fd89c5a75",
        "https://git.kernel.org/stable/c/df6134b527a88b3e65ba6ae5073664af091d5fd2",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72006.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-72006",
        "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-2026-72006.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-72006",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 517575,
  "published_at": "2026-08-15T05:51:36.635+00:00"
}