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

Vulnerability from cvelistv5 – Published: 2026-05-27 12:17 – Updated: 2026-05-30 10:41
VLAI
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
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: ddf854e59166533b0f46ba32cd6cd9aca3197d1b , < 28db4bfc6f82fd20e2aadb7fc162244109a4eb31 (git)
Affected: 58ddae5d77b1db3a27b891c75a8fa120239ac092 , < f0931a5c17005a0c4fc35bd1a001245effc3354b (git)
Affected: d17857b4fb9ba5745b59be0ef38fd532991fccbf , < d8ee559fccdef713f058cfe5f2c03dc9b18be3b1 (git)
Affected: d67c8ecf3d8fda9b8ef80e6f665d84b6d6ac9d88 , < c2ee51d684adca7645e4aa74adca13f6750390bc (git)
Affected: 7015fcf473796e1d2d876f241bd9e0c36f3d4eef , < a1b962a821e7a52d48212ae269b45808b4411267 (git)
Affected: 1bf6974822d1dba86cf11b5f05498581cf3488a2 , < 6d882ea3b0931b43530d44149b79fcd4ffc13030 (git)
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Linux Linux Affected: 6.1.167 , < 6.1.168 (semver)
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Show details on NVD website
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ext4/extents.c"
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              "versionType": "git"
            },
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              "version": "d67c8ecf3d8fda9b8ef80e6f665d84b6d6ac9d88",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "7015fcf473796e1d2d876f241bd9e0c36f3d4eef",
              "versionType": "git"
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              "versionType": "git"
            }
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        },
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          "product": "Linux",
          "programFiles": [
            "fs/ext4/extents.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6.1.168",
              "status": "affected",
              "version": "6.1.167",
              "versionType": "semver"
            }
          ]
        }
      ],
      "cpeApplicability": [
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              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.168",
                  "versionStartIncluding": "6.1.167",
                  "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": "2026-05-30T10:41:42.703Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/f0931a5c17005a0c4fc35bd1a001245effc3354b"
        },
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          "url": "https://git.kernel.org/stable/c/d8ee559fccdef713f058cfe5f2c03dc9b18be3b1"
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        },
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        },
        {
          "url": "https://git.kernel.org/stable/c/6d882ea3b0931b43530d44149b79fcd4ffc13030"
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      "title": "ext4: drop extent cache after doing PARTIAL_VALID1 zeroout",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-45892",
    "datePublished": "2026-05-27T12:17:03.175Z",
    "dateReserved": "2026-05-13T15:03:33.083Z",
    "dateUpdated": "2026-05-30T10:41:42.703Z",
    "state": "PUBLISHED"
  },
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      "date": "2026-09-17",
      "epss": "0.0016",
      "percentile": "0.05648"
    },
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      "cve": "CVE-2026-45892",
      "id": "msrc_CVE-2026-45892",
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      "product_status:fixed": "1",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "ext4: drop extent cache after doing PARTIAL_VALID1 zeroout",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-45892.json",
      "version": "2"
    },
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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.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/ext4/extents.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"ddf854e59166533b0f46ba32cd6cd9aca3197d1b\",\"lessThan\":\"28db4bfc6f82fd20e2aadb7fc162244109a4eb31\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"58ddae5d77b1db3a27b891c75a8fa120239ac092\",\"lessThan\":\"f0931a5c17005a0c4fc35bd1a001245effc3354b\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"d17857b4fb9ba5745b59be0ef38fd532991fccbf\",\"lessThan\":\"d8ee559fccdef713f058cfe5f2c03dc9b18be3b1\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"d67c8ecf3d8fda9b8ef80e6f665d84b6d6ac9d88\",\"lessThan\":\"c2ee51d684adca7645e4aa74adca13f6750390bc\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"7015fcf473796e1d2d876f241bd9e0c36f3d4eef\",\"lessThan\":\"a1b962a821e7a52d48212ae269b45808b4411267\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1bf6974822d1dba86cf11b5f05498581cf3488a2\",\"lessThan\":\"6d882ea3b0931b43530d44149b79fcd4ffc13030\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/ext4/extents.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.1.167\",\"lessThan\":\"6.1.168\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":5.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"NVD-CWE-noinfo\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:6.1.167:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"B898A4FB-4E74-40F7-B523-B71FFB681B6D\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/28db4bfc6f82fd20e2aadb7fc162244109a4eb31\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/6d882ea3b0931b43530d44149b79fcd4ffc13030\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/a1b962a821e7a52d48212ae269b45808b4411267\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/c2ee51d684adca7645e4aa74adca13f6750390bc\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/d8ee559fccdef713f058cfe5f2c03dc9b18be3b1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/f0931a5c17005a0c4fc35bd1a001245effc3354b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-27T16:19:40+00:00",
      "cve": "CVE-2026-45892",
      "id": "CVE-2026-45892",
      "initial_release_date": "2026-05-27T00:00:00+00:00",
      "product_status:known_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ext4: drop extent cache after doing PARTIAL_VALID1 zeroout",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45892.json",
      "version": "3"
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      "cve": "CVE-2026-45892",
      "id": "CVE-2026-45892",
      "initial_release_date": "2026-05-28T03:56:44Z",
      "product_status:known_not_affected": "299",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-45892",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-45892.json",
      "version": "5"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
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