{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "dee1f973ca341c266229faa5a1a5bb268bed3531"
            },
            {
              "fixed": "58ddae5d77b1db3a27b891c75a8fa120239ac092"
            },
            {
              "fixed": "d17857b4fb9ba5745b59be0ef38fd532991fccbf"
            },
            {
              "fixed": "d67c8ecf3d8fda9b8ef80e6f665d84b6d6ac9d88"
            },
            {
              "fixed": "7015fcf473796e1d2d876f241bd9e0c36f3d4eef"
            },
            {
              "fixed": "1bf6974822d1dba86cf11b5f05498581cf3488a2"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "814a7833df19e1de7447f870ae890adb12561627"
            },
            {
              "last_affected": "4319fd00002630a761fa5559a086f11ed7623006"
            },
            {
              "last_affected": "e28b27be06c5e6a5236c0c0b370ca0768ab086bb"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "3.2.33"
            },
            {
              "fixed": "3.3"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "3.4.16"
            },
            {
              "fixed": "3.5"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "3.6.4"
            },
            {
              "fixed": "3.7"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.7.0"
            },
            {
              "fixed": "6.6.130"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.75"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.14"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45858.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1\n\nWhen allocating initialized blocks from a large unwritten extent, or\nwhen splitting an unwritten extent during end I/O and converting it to\ninitialized, there is currently a potential issue of stale data if the\nextent needs to be split in the middle.\n\n       0  A      B  N\n       [UUUUUUUUUUUU]    U: unwritten extent\n       [--DDDDDDDD--]    D: valid data\n          |\u003c-  -\u003e| ----\u003e this range needs to be initialized\n\next4_split_extent() first try to split this extent at B with\nEXT4_EXT_DATA_ENTIRE_VALID1 and EXT4_EXT_MAY_ZEROOUT flag set, but\next4_split_extent_at() failed to split this extent due to temporary lack\nof space. It zeroout B to N and mark the entire extent from 0 to N\nas written.\n\n       0  A      B  N\n       [WWWWWWWWWWWW]    W: written extent\n       [SSDDDDDDDDZZ]    Z: zeroed, S: stale data\n\next4_split_extent() then try to split this extent at A with\nEXT4_EXT_DATA_VALID2 flag set. This time, it split successfully and left\na stale written extent from 0 to A.\n\n       0  A      B   N\n       [WW|WWWWWWWWWW]\n       [SS|DDDDDDDDZZ]\n\nFix this by pass EXT4_EXT_DATA_PARTIAL_VALID1 to ext4_split_extent_at()\nwhen splitting at B, don't convert the entire extent to written and left\nit as unwritten after zeroing out B to N. The remaining work is just\nlike the standard two-part split. ext4_split_extent() will pass the\nEXT4_EXT_DATA_VALID2 flag when it calls ext4_split_extent_at() for the\nsecond time, allowing it to properly handle the split. If the split is\nsuccessful, it will keep extent from 0 to A as unwritten.",
  "id": "CVE-2026-45858",
  "modified": "2026-07-15T01:49:20.535639406Z",
  "published": "2026-05-27T12:15:37.738Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1bf6974822d1dba86cf11b5f05498581cf3488a2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/58ddae5d77b1db3a27b891c75a8fa120239ac092"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7015fcf473796e1d2d876f241bd9e0c36f3d4eef"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d17857b4fb9ba5745b59be0ef38fd532991fccbf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d67c8ecf3d8fda9b8ef80e6f665d84b6d6ac9d88"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45858.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45858"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "ext4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1"
}