Vulnerability-Lookup

GHSA-RQ43-8P3G-5CC4

Vulnerability from github – Published: 2026-04-22 15:31 – Updated: 2026-04-22 15:31

Details

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

ext4: validate p_idx bounds in ext4_ext_correct_indexes

ext4_ext_correct_indexes() walks up the extent tree correcting index entries when the first extent in a leaf is modified. Before accessing path[k].p_idx->ei_block, there is no validation that p_idx falls within the valid range of index entries for that level.

If the on-disk extent header contains a corrupted or crafted eh_entries value, p_idx can point past the end of the allocated buffer, causing a slab-out-of-bounds read.

Fix this by validating path[k].p_idx against EXT_LAST_INDEX() at both access sites: before the while loop and inside it. Return -EFSCORRUPTED if the index pointer is out of range, consistent with how other bounds violations are handled in the ext4 extent tree code.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-31449"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-22T14:16:38Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: validate p_idx bounds in ext4_ext_correct_indexes\n\next4_ext_correct_indexes() walks up the extent tree correcting\nindex entries when the first extent in a leaf is modified. Before\naccessing path[k].p_idx-\u003eei_block, there is no validation that\np_idx falls within the valid range of index entries for that\nlevel.\n\nIf the on-disk extent header contains a corrupted or crafted\neh_entries value, p_idx can point past the end of the allocated\nbuffer, causing a slab-out-of-bounds read.\n\nFix this by validating path[k].p_idx against EXT_LAST_INDEX() at\nboth access sites: before the while loop and inside it. Return\n-EFSCORRUPTED if the index pointer is out of range, consistent\nwith how other bounds violations are handled in the ext4 extent\ntree code.",
  "id": "GHSA-rq43-8p3g-5cc4",
  "modified": "2026-04-22T15:31:41Z",
  "published": "2026-04-22T15:31:41Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31449"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/01bf1e0b997d82c0e353b51ed74ef99698043c33"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2acb5c12ebd860f30e4faf67e6cc8c44ddfe5fe8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/407c944f217c17d4343148011acafebc604d55e1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/93f2e975ed658ce09db4d4c2877ca2c06540df83"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-31449 (GCVE-0-2026-31449)

Vulnerability from cvelistv5 – Published: 2026-04-22 13:53 – Updated: 2026-04-23 15:18

Title

ext4: validate p_idx bounds in ext4_ext_correct_indexes

Summary

In the Linux kernel, the following vulnerability has been resolved: ext4: validate p_idx bounds in ext4_ext_correct_indexes ext4_ext_correct_indexes() walks up the extent tree correcting index entries when the first extent in a leaf is modified. Before accessing path[k].p_idx->ei_block, there is no validation that p_idx falls within the valid range of index entries for that level. If the on-disk extent header contains a corrupted or crafted eh_entries value, p_idx can point past the end of the allocated buffer, causing a slab-out-of-bounds read. Fix this by validating path[k].p_idx against EXT_LAST_INDEX() at both access sites: before the while loop and inside it. Return -EFSCORRUPTED if the index pointer is out of range, consistent with how other bounds violations are handled in the ext4 extent tree code.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/407c944f217c17d43…
	https://git.kernel.org/stable/c/93f2e975ed658ce09…
	https://git.kernel.org/stable/c/01bf1e0b997d82c0e…
	https://git.kernel.org/stable/c/2acb5c12ebd860f30…

Impacted products

Vendor

Product

Version

Linux

Affected: a86c61812637c7dd0c57e29880cffd477b62f2e7 , < 407c944f217c17d4343148011acafebc604d55e1 (git)
Affected: a86c61812637c7dd0c57e29880cffd477b62f2e7 , < 93f2e975ed658ce09db4d4c2877ca2c06540df83 (git)
Affected: a86c61812637c7dd0c57e29880cffd477b62f2e7 , < 01bf1e0b997d82c0e353b51ed74ef99698043c33 (git)
Affected: a86c61812637c7dd0c57e29880cffd477b62f2e7 , < 2acb5c12ebd860f30e4faf67e6cc8c44ddfe5fe8 (git)

Linux

Affected: 2.6.19
Unaffected: 0 , < 2.6.19 (semver)
Unaffected: 6.12.80 , ≤ 6.12.* (semver)
Unaffected: 6.18.21 , ≤ 6.18.* (semver)
Unaffected: 6.19.11 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)

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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": [
            {
              "lessThan": "407c944f217c17d4343148011acafebc604d55e1",
              "status": "affected",
              "version": "a86c61812637c7dd0c57e29880cffd477b62f2e7",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "a86c61812637c7dd0c57e29880cffd477b62f2e7",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "a86c61812637c7dd0c57e29880cffd477b62f2e7",
              "versionType": "git"
            },
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          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.19"
            },
            {
              "lessThan": "2.6.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.80",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.21",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.11",
              "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": "6.12.80",
                  "versionStartIncluding": "2.6.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                },
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: validate p_idx bounds in ext4_ext_correct_indexes\n\next4_ext_correct_indexes() walks up the extent tree correcting\nindex entries when the first extent in a leaf is modified. Before\naccessing path[k].p_idx-\u003eei_block, there is no validation that\np_idx falls within the valid range of index entries for that\nlevel.\n\nIf the on-disk extent header contains a corrupted or crafted\neh_entries value, p_idx can point past the end of the allocated\nbuffer, causing a slab-out-of-bounds read.\n\nFix this by validating path[k].p_idx against EXT_LAST_INDEX() at\nboth access sites: before the while loop and inside it. Return\n-EFSCORRUPTED if the index pointer is out of range, consistent\nwith how other bounds violations are handled in the ext4 extent\ntree code."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-23T15:18:27.546Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/407c944f217c17d4343148011acafebc604d55e1"
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        {
          "url": "https://git.kernel.org/stable/c/01bf1e0b997d82c0e353b51ed74ef99698043c33"
        },
        {
          "url": "https://git.kernel.org/stable/c/2acb5c12ebd860f30e4faf67e6cc8c44ddfe5fe8"
        }
      ],
      "title": "ext4: validate p_idx bounds in ext4_ext_correct_indexes",
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    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31449",
    "datePublished": "2026-04-22T13:53:44.777Z",
    "dateReserved": "2026-03-09T15:48:24.091Z",
    "dateUpdated": "2026-04-23T15:18:27.546Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

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-RQ43-8P3G-5CC4

CVE-2026-31449 (GCVE-0-2026-31449)

Tags

Sightings

Nomenclature