{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: don\u0027t cache extent during splitting extent\n\nCaching extents during the splitting process is risky, as it may result\nin stale extents remaining in the status tree. Moreover, in most cases,\nthe corresponding extent block entries are likely already cached before\nthe split happens, making caching here not particularly useful.\n\nAssume we have an unwritten extent, and then DIO writes the first half.\n\n  [UUUUUUUUUUUUUUUU] on-disk extent        U: unwritten extent\n  [UUUUUUUUUUUUUUUU] extent status tree\n  |\u003c-   -\u003e| ----\u003e dio write this range\n\nFirst, when ext4_split_extent_at() splits this extent, it truncates the\nexisting extent and then inserts a new one. During this process, this\nextent status entry may be shrunk, and calls to ext4_find_extent() and\next4_cache_extents() may occur, which could potentially insert the\ntruncated range as a hole into the extent status tree. After the split\nis completed, this hole is not replaced with the correct status.\n\n  [UUUUUUU|UUUUUUUU] on-disk extent        U: unwritten extent\n  [UUUUUUU|HHHHHHHH] extent status tree    H: hole\n\nThen, the outer calling functions will not correct this remaining hole\nextent either. Finally, if we perform a delayed buffer write on this\nlatter part, it will re-insert the delayed extent and cause an error in\nspace accounting.\n\nIn adition, if the unwritten extent cache is not shrunk during the\nsplitting, ext4_cache_extents() also conflicts with existing extents\nwhen caching extents. In the future, we will add checks when caching\nextents, which will trigger a warning. Therefore, Do not cache extents\nthat are being split."
    }
  ],
  "id": "CVE-2026-45912",
  "lastModified": "2026-05-27T14:48:03.013",
  "metrics": {},
  "published": "2026-05-27T14:17:05.867",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4c2d9dac4d328244f9365b0a1fa27ec802821820"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5b1f4290453314e11cd8e15c7baa8a9b76c19b23"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/692103feca376ae4298c92aa8828015d20f1d87b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8302b5b4aacdbb378f7b1216bb2ee782b5142415"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8b4b19a2f96348d70bfa306ef7d4a13b0bcbea79"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/93b2ebbbcb2e63cfc21a1946dfe91d3aa7952036"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/96007fd3c106aea773c1afae2d6f64cceb6da208"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9a2b95cdaf07785e2739199037bd9c0863ccc1be"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-45912"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-27T14:17:05Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: don\u0027t cache extent during splitting extent\n\nCaching extents during the splitting process is risky, as it may result\nin stale extents remaining in the status tree. Moreover, in most cases,\nthe corresponding extent block entries are likely already cached before\nthe split happens, making caching here not particularly useful.\n\nAssume we have an unwritten extent, and then DIO writes the first half.\n\n  [UUUUUUUUUUUUUUUU] on-disk extent        U: unwritten extent\n  [UUUUUUUUUUUUUUUU] extent status tree\n  |\u003c-   -\u003e| ----\u003e dio write this range\n\nFirst, when ext4_split_extent_at() splits this extent, it truncates the\nexisting extent and then inserts a new one. During this process, this\nextent status entry may be shrunk, and calls to ext4_find_extent() and\next4_cache_extents() may occur, which could potentially insert the\ntruncated range as a hole into the extent status tree. After the split\nis completed, this hole is not replaced with the correct status.\n\n  [UUUUUUU|UUUUUUUU] on-disk extent        U: unwritten extent\n  [UUUUUUU|HHHHHHHH] extent status tree    H: hole\n\nThen, the outer calling functions will not correct this remaining hole\nextent either. Finally, if we perform a delayed buffer write on this\nlatter part, it will re-insert the delayed extent and cause an error in\nspace accounting.\n\nIn adition, if the unwritten extent cache is not shrunk during the\nsplitting, ext4_cache_extents() also conflicts with existing extents\nwhen caching extents. In the future, we will add checks when caching\nextents, which will trigger a warning. Therefore, Do not cache extents\nthat are being split.",
  "id": "GHSA-2r5x-f6hq-8f5p",
  "modified": "2026-05-27T15:33:16Z",
  "published": "2026-05-27T15:33:16Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45912"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4c2d9dac4d328244f9365b0a1fa27ec802821820"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5b1f4290453314e11cd8e15c7baa8a9b76c19b23"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/692103feca376ae4298c92aa8828015d20f1d87b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8302b5b4aacdbb378f7b1216bb2ee782b5142415"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8b4b19a2f96348d70bfa306ef7d4a13b0bcbea79"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/93b2ebbbcb2e63cfc21a1946dfe91d3aa7952036"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/96007fd3c106aea773c1afae2d6f64cceb6da208"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9a2b95cdaf07785e2739199037bd9c0863ccc1be"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "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"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2026-45912 ext4: don\u0027t cache extent during splitting extent - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-45912.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "ext4: don\u0027t cache extent during splitting extent",
    "tracking": {
      "current_release_date": "2026-05-28T14:48:19.000Z",
      "generator": {
        "date": "2026-05-29T07:23:45.828Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-45912",
      "initial_release_date": "2026-05-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-05-28T01:05:36.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        },
        {
          "date": "2026-05-28T14:48:19.000Z",
          "legacy_version": "2",
          "number": "2",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "2"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "3.0",
                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003cazl3 kernel 0:6.6.139.1-1.azl3",
                "product": {
                  "name": "\u003cazl3 kernel 0:6.6.139.1-1.azl3",
                  "product_id": "1"
                }
              },
              {
                "category": "product_version",
                "name": "azl3 kernel 0:6.6.139.1-1.azl3",
                "product": {
                  "name": "azl3 kernel 0:6.6.139.1-1.azl3",
                  "product_id": "21344"
                }
              }
            ],
            "category": "product_name",
            "name": "kernel"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "\u003cazl3 kernel 0:6.6.139.1-1.azl3 as a component of Azure Linux 3.0",
          "product_id": "17084-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "17084"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 kernel 0:6.6.139.1-1.azl3 as a component of Azure Linux 3.0",
          "product_id": "21344-17084"
        },
        "product_reference": "21344",
        "relates_to_product_reference": "17084"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-45912",
      "notes": [
        {
          "category": "general",
          "text": "Linux",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "fixed": [
          "21344-17084"
        ],
        "known_affected": [
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-45912 ext4: don\u0027t cache extent during splitting extent - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-45912.json"
        }
      ],
      "title": "ext4: don\u0027t cache extent during splitting extent"
    }
  ]
}