{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm-thin: fix metadata refcount underflow\n\nThere\u0027s a bug in dm-thin in the function rebalance_children. If the\ninternal btree node has one entry, the code tries to copy all btree\nentries from the node\u0027s child to the node itself and then decrement the\nchild\u0027s reference count.\n\nIf the child node is shared (it has reference count \u003e 1), we won\u0027t free\nit, so there would be two pointers to each of the grandchildren nodes.\nBut the reference counts of the grandchildren is not increased, thus the\nreference count doesn\u0027t match the number of pointers that point to the\ngrandchildren. This results in \"device mapper: space map common: unable\nto decrement block\" errors.\n\nFix this bug by incrementing reference counts on the grandchildren if the\nbtree node is shared."
    }
  ],
  "id": "CVE-2026-46107",
  "lastModified": "2026-05-28T13:44:01.663",
  "metrics": {},
  "published": "2026-05-28T10:16:26.063",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/09a65adc7d8bbfce06392cb6d375468e2728ead5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/12161e03d33afce781f68fa11cc6060538862fad"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/323d252a4a378834e4fe68298ca61cfc5dd3a460"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5ec0debbcfd43596e32c1239e993de06a704e04c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/85311a585a26640760cd0f3349ab9f2905691044"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-46107"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-28T10:16:26Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm-thin: fix metadata refcount underflow\n\nThere\u0027s a bug in dm-thin in the function rebalance_children. If the\ninternal btree node has one entry, the code tries to copy all btree\nentries from the node\u0027s child to the node itself and then decrement the\nchild\u0027s reference count.\n\nIf the child node is shared (it has reference count \u003e 1), we won\u0027t free\nit, so there would be two pointers to each of the grandchildren nodes.\nBut the reference counts of the grandchildren is not increased, thus the\nreference count doesn\u0027t match the number of pointers that point to the\ngrandchildren. This results in \"device mapper: space map common: unable\nto decrement block\" errors.\n\nFix this bug by incrementing reference counts on the grandchildren if the\nbtree node is shared.",
  "id": "GHSA-c6hr-v224-3w2w",
  "modified": "2026-05-28T12:30:28Z",
  "published": "2026-05-28T12:30:28Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46107"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/09a65adc7d8bbfce06392cb6d375468e2728ead5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/12161e03d33afce781f68fa11cc6060538862fad"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/323d252a4a378834e4fe68298ca61cfc5dd3a460"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5ec0debbcfd43596e32c1239e993de06a704e04c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/85311a585a26640760cd0f3349ab9f2905691044"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

{
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        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
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        "summary": "CVE-2026-46107 dm-thin: fix metadata refcount underflow - VEX",
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        "url": "https://support.microsoft.com/lifecycle"
      },
      {
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        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "dm-thin: fix metadata refcount underflow",
    "tracking": {
      "current_release_date": "2026-05-29T01:05:13.000Z",
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      "revision_history": [
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      "notes": [
        {
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          "text": "Linux",
          "title": "Assigning CNA"
        }
      ],
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        }
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}