mm/memory_hotplug: fix memory block reference leak on remove

{
  "id": "53b647b73748886b02661d1f5e2d570ffd1858159b8dfb3e51e564048c1db2d8",
  "url": "https://osv.dev/vulnerability/CVE-2026-64180",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "mm/memory_hotplug: fix memory block reference leak on remove",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: mm/memory_hotplug: fix memory block reference leak on remove Patch series \"mm: Fix memory block leaks and locking\", v2. This series fixes two memory block device reference leaks and one locking issue around the per-memory_block hwpoison counter. This patch (of 2): remove_memory_blocks_and_altmaps() looks up each memory block with find_memory_block(), which acquires a reference to the memory block device. That reference is never dropped on this path, resulting in a leaked device reference when removing memory blocks and their altmaps. Drop the reference after retrieving mem->altmap and clearing mem->altmap, before removing the memory block device.",
    "evidence": "osv:CVE-2026-64180",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.92",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.34",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.11",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-64180",
      "aliases": [
        "CVE-2026-64180"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "6b8f0798b85aa529011570369db985a788f3003f"
                },
                {
                  "fixed": "b8ab30c79fc00147125b9c39f928561d9dd13d06"
                },
                {
                  "fixed": "09ce923071e7852ece60d7368e05249bf32c7967"
                },
                {
                  "fixed": "df64c0d21c3f85f844b2f656333e43d97e6ffa74"
                },
                {
                  "fixed": "93866f55f7e292fe3d47d36c9efe5ee10213a06b"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64180.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.8.0"
                },
                {
                  "fixed": "6.12.92"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.34"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.11"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64180.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:24.127236804Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/09ce923071e7852ece60d7368e05249bf32c7967",
        "https://git.kernel.org/stable/c/93866f55f7e292fe3d47d36c9efe5ee10213a06b",
        "https://git.kernel.org/stable/c/b8ab30c79fc00147125b9c39f928561d9dd13d06",
        "https://git.kernel.org/stable/c/df64c0d21c3f85f844b2f656333e43d97e6ffa74",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64180.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-64180",
        "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/2026/64xxx/CVE-2026-64180.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-64180",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 490319,
  "published_at": "2026-07-19T15:41:03.751+00:00"
}