Vulnerability-Lookup

GHSA-XQ2X-F6M4-2HRP

Vulnerability from github – Published: 2026-05-27 15:33 – Updated: 2026-05-27 15:33

Details

In the Linux kernel, the following vulnerability has been resolved:

ext4: drop extent cache after doing PARTIAL_VALID1 zeroout

When splitting an unwritten extent in the middle and converting it to initialized in ext4_split_extent() with the EXT4_EXT_MAY_ZEROOUT and EXT4_EXT_DATA_VALID2 flags set, it could leave a stale unwritten extent.

Assume we have an unwritten file and buffered write in the middle of it without dioread_nolock enabled, it will allocate blocks as written extent.

   0  A      B  N
   [UUUUUUUUUUUU] on-disk extent      U: unwritten extent
   [UUUUUUUUUUUU] extent status tree
   [--DDDDDDDD--]                     D: valid data
      |<-  ->| ----> this range needs to be initialized

ext4_split_extent() first try to split this extent at B with EXT4_EXT_DATA_PARTIAL_VALID1 and EXT4_EXT_MAY_ZEROOUT flag set, but ext4_split_extent_at() failed to split this extent due to temporary lack of space. It zeroout B to N and leave the entire extent as unwritten.

   0  A      B  N
   [UUUUUUUUUUUU] on-disk extent
   [UUUUUUUUUUUU] extent status tree
   [--DDDDDDDDZZ]                     Z: zeroed data

ext4_split_extent() then try to split this extent at A with EXT4_EXT_DATA_VALID2 flag set. This time, it split successfully and leave an written extent from A to N.

   0  A      B  N
   [UUWWWWWWWWWW] on-disk extent      W: written extent
   [UUUUUUUUUUUU] extent status tree
   [--DDDDDDDDZZ]

Finally ext4_map_create_blocks() only insert extent A to B to the extent status tree, and leave an stale unwritten extent in the status tree.

   0  A      B  N
   [UUWWWWWWWWWW] on-disk extent      W: written extent
   [UUWWWWWWWWUU] extent status tree
   [--DDDDDDDDZZ]

Fix this issue by always cached extent status entry after zeroing out the second part.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-45892"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-27T14:17:03Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: drop extent cache after doing PARTIAL_VALID1 zeroout\n\nWhen splitting an unwritten extent in the middle and converting it to\ninitialized in ext4_split_extent() with the EXT4_EXT_MAY_ZEROOUT and\nEXT4_EXT_DATA_VALID2 flags set, it could leave a stale unwritten extent.\n\nAssume we have an unwritten file and buffered write in the middle of it\nwithout dioread_nolock enabled, it will allocate blocks as written\nextent.\n\n       0  A      B  N\n       [UUUUUUUUUUUU] on-disk extent      U: unwritten extent\n       [UUUUUUUUUUUU] extent status tree\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_PARTIAL_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 leave the entire extent as unwritten.\n\n       0  A      B  N\n       [UUUUUUUUUUUU] on-disk extent\n       [UUUUUUUUUUUU] extent status tree\n       [--DDDDDDDDZZ]                     Z: zeroed 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\nleave an written extent from A to N.\n\n       0  A      B  N\n       [UUWWWWWWWWWW] on-disk extent      W: written extent\n       [UUUUUUUUUUUU] extent status tree\n       [--DDDDDDDDZZ]\n\nFinally ext4_map_create_blocks() only insert extent A to B to the extent\nstatus tree, and leave an stale unwritten extent in the status tree.\n\n       0  A      B  N\n       [UUWWWWWWWWWW] on-disk extent      W: written extent\n       [UUWWWWWWWWUU] extent status tree\n       [--DDDDDDDDZZ]\n\nFix this issue by always cached extent status entry after zeroing out\nthe second part.",
  "id": "GHSA-xq2x-f6m4-2hrp",
  "modified": "2026-05-27T15:33:15Z",
  "published": "2026-05-27T15:33:15Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45892"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6d882ea3b0931b43530d44149b79fcd4ffc13030"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a1b962a821e7a52d48212ae269b45808b4411267"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c2ee51d684adca7645e4aa74adca13f6750390bc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d8ee559fccdef713f058cfe5f2c03dc9b18be3b1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f0931a5c17005a0c4fc35bd1a001245effc3354b"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-45892 (GCVE-0-2026-45892)

Vulnerability from cvelistv5 – Published: 2026-05-27 12:17 – Updated: 2026-05-27 12:17

Title

ext4: drop extent cache after doing PARTIAL_VALID1 zeroout

Summary

In the Linux kernel, the following vulnerability has been resolved: ext4: drop extent cache after doing PARTIAL_VALID1 zeroout When splitting an unwritten extent in the middle and converting it to initialized in ext4_split_extent() with the EXT4_EXT_MAY_ZEROOUT and EXT4_EXT_DATA_VALID2 flags set, it could leave a stale unwritten extent. Assume we have an unwritten file and buffered write in the middle of it without dioread_nolock enabled, it will allocate blocks as written extent. 0 A B N [UUUUUUUUUUUU] on-disk extent U: unwritten extent [UUUUUUUUUUUU] extent status tree [--DDDDDDDD--] D: valid data |<- ->| ----> this range needs to be initialized ext4_split_extent() first try to split this extent at B with EXT4_EXT_DATA_PARTIAL_VALID1 and EXT4_EXT_MAY_ZEROOUT flag set, but ext4_split_extent_at() failed to split this extent due to temporary lack of space. It zeroout B to N and leave the entire extent as unwritten. 0 A B N [UUUUUUUUUUUU] on-disk extent [UUUUUUUUUUUU] extent status tree [--DDDDDDDDZZ] Z: zeroed data ext4_split_extent() then try to split this extent at A with EXT4_EXT_DATA_VALID2 flag set. This time, it split successfully and leave an written extent from A to N. 0 A B N [UUWWWWWWWWWW] on-disk extent W: written extent [UUUUUUUUUUUU] extent status tree [--DDDDDDDDZZ] Finally ext4_map_create_blocks() only insert extent A to B to the extent status tree, and leave an stale unwritten extent in the status tree. 0 A B N [UUWWWWWWWWWW] on-disk extent W: written extent [UUWWWWWWWWUU] extent status tree [--DDDDDDDDZZ] Fix this issue by always cached extent status entry after zeroing out the second part.

Severity

No CVSS data available.

Assigner

Linux

References

5 references

URL	Tags
https://git.kernel.org/stable/c/f0931a5c17005a0c4…
https://git.kernel.org/stable/c/d8ee559fccdef713f…
https://git.kernel.org/stable/c/c2ee51d684adca764…
https://git.kernel.org/stable/c/a1b962a821e7a52d4…
https://git.kernel.org/stable/c/6d882ea3b0931b435…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < f0931a5c17005a0c4fc35bd1a001245effc3354b (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < d8ee559fccdef713f058cfe5f2c03dc9b18be3b1 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < c2ee51d684adca7645e4aa74adca13f6750390bc (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < a1b962a821e7a52d48212ae269b45808b4411267 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 6d882ea3b0931b43530d44149b79fcd4ffc13030 (git) Affected: 0 , < 6.6.130 (semver) Affected: 0 , < 6.12.75 (semver) Affected: 0 , < 6.18.14 (semver) Affected: 0 , < 6.19.4 (semver)
Linux	Linux	Unaffected: 6.6.130 , ≤ 6.6.* (semver) Unaffected: 6.12.75 , ≤ 6.12.* (semver) Unaffected: 6.18.14 , ≤ 6.18.* (semver) Unaffected: 6.19.4 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

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JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ext4/extents.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
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              "versionType": "git"
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              "status": "affected",
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              "versionType": "git"
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            {
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              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "6d882ea3b0931b43530d44149b79fcd4ffc13030",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
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              "version": "0",
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            {
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              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "6.18.14",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "6.19.4",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/ext4/extents.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.130",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.75",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.130",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.75",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.14",
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                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: drop extent cache after doing PARTIAL_VALID1 zeroout\n\nWhen splitting an unwritten extent in the middle and converting it to\ninitialized in ext4_split_extent() with the EXT4_EXT_MAY_ZEROOUT and\nEXT4_EXT_DATA_VALID2 flags set, it could leave a stale unwritten extent.\n\nAssume we have an unwritten file and buffered write in the middle of it\nwithout dioread_nolock enabled, it will allocate blocks as written\nextent.\n\n       0  A      B  N\n       [UUUUUUUUUUUU] on-disk extent      U: unwritten extent\n       [UUUUUUUUUUUU] extent status tree\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_PARTIAL_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 leave the entire extent as unwritten.\n\n       0  A      B  N\n       [UUUUUUUUUUUU] on-disk extent\n       [UUUUUUUUUUUU] extent status tree\n       [--DDDDDDDDZZ]                     Z: zeroed 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\nleave an written extent from A to N.\n\n       0  A      B  N\n       [UUWWWWWWWWWW] on-disk extent      W: written extent\n       [UUUUUUUUUUUU] extent status tree\n       [--DDDDDDDDZZ]\n\nFinally ext4_map_create_blocks() only insert extent A to B to the extent\nstatus tree, and leave an stale unwritten extent in the status tree.\n\n       0  A      B  N\n       [UUWWWWWWWWWW] on-disk extent      W: written extent\n       [UUWWWWWWWWUU] extent status tree\n       [--DDDDDDDDZZ]\n\nFix this issue by always cached extent status entry after zeroing out\nthe second part."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-27T12:17:03.175Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f0931a5c17005a0c4fc35bd1a001245effc3354b"
        },
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          "url": "https://git.kernel.org/stable/c/d8ee559fccdef713f058cfe5f2c03dc9b18be3b1"
        },
        {
          "url": "https://git.kernel.org/stable/c/c2ee51d684adca7645e4aa74adca13f6750390bc"
        },
        {
          "url": "https://git.kernel.org/stable/c/a1b962a821e7a52d48212ae269b45808b4411267"
        },
        {
          "url": "https://git.kernel.org/stable/c/6d882ea3b0931b43530d44149b79fcd4ffc13030"
        }
      ],
      "title": "ext4: drop extent cache after doing PARTIAL_VALID1 zeroout",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-45892",
    "datePublished": "2026-05-27T12:17:03.175Z",
    "dateReserved": "2026-05-13T15:03:33.083Z",
    "dateUpdated": "2026-05-27T12:17:03.175Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-XQ2X-F6M4-2HRP

CVE-2026-45892 (GCVE-0-2026-45892)

Tags

Sightings

Nomenclature