CVE-2026-31449 (GCVE-0-2026-31449)
Vulnerability from cvelistv5
Published
2026-04-22 13:53
Modified
2026-04-27 14:03
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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.
References
Impacted products
Vendor Product Version
Linux Linux Version: a86c61812637c7dd0c57e29880cffd477b62f2e7
Version: a86c61812637c7dd0c57e29880cffd477b62f2e7
Version: a86c61812637c7dd0c57e29880cffd477b62f2e7
Version: a86c61812637c7dd0c57e29880cffd477b62f2e7
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{
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          "programFiles": [
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              "operator": "OR"
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      "descriptions": [
        {
          "lang": "en",
          "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."
        }
      ],
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
            "version": "3.1"
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        "dateUpdated": "2026-04-27T14:03:14.969Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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          "url": "https://git.kernel.org/stable/c/407c944f217c17d4343148011acafebc604d55e1"
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          "url": "https://git.kernel.org/stable/c/93f2e975ed658ce09db4d4c2877ca2c06540df83"
        },
        {
          "url": "https://git.kernel.org/stable/c/01bf1e0b997d82c0e353b51ed74ef99698043c33"
        },
        {
          "url": "https://git.kernel.org/stable/c/2acb5c12ebd860f30e4faf67e6cc8c44ddfe5fe8"
        }
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      "title": "ext4: validate p_idx bounds in ext4_ext_correct_indexes",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31449",
    "datePublished": "2026-04-22T13:53:44.777Z",
    "dateReserved": "2026-03-09T15:48:24.091Z",
    "dateUpdated": "2026-04-27T14:03:14.969Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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