CVE-2026-89841

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: f2fs: only redirty pinned folios in redirty_blocks redirty_blocks() pins folios with read_cache_folio() and then walks the same range again with filemap_lock_folio() to redirty them and drop the references it took. Commit 5951fee46bef ("f2fs: Use a folio in redirty_blocks()") changed the second pass to a do/while loop. If read_cache_folio() fails before anything is pinned, page_idx does not advance but the cleanup loop still runs once. If readahead has already populated the failed folio in page cache, that extra iteration finds it and folio_put_refs(folio, 2) drops one reference too many. Later drop_caches or reclaim can then report "BUG: Bad page state". Only redirty the range that was pinned successfully.

Severity

HIGH

CVSS score

7.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-16 11:16:50.937000

Last modified

2026-10-19 09:18:28.030000

View original CVE JSON

{
  "id": "CVE-2026-89841",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-16T11:16:50.937",
  "lastModified": "2026-10-19T09:18:28.030",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: only redirty pinned folios in redirty_blocks\n\nredirty_blocks() pins folios with read_cache_folio() and then walks the\nsame range again with filemap_lock_folio() to redirty them and drop the\nreferences it took.\n\nCommit 5951fee46bef (\"f2fs: Use a folio in redirty_blocks()\") changed\nthe second pass to a do/while loop. If read_cache_folio() fails before\nanything is pinned, page_idx does not advance but the cleanup loop still\nruns once.\n\nIf readahead has already populated the failed folio in page cache, that\nextra iteration finds it and folio_put_refs(folio, 2) drops one\nreference too many. Later drop_caches or reclaim can then report\n\"BUG: Bad page state\".\n\nOnly redirty the range that was pinned successfully."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/f2fs/file.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5951fee46befbf6176c86482432f4f76e522f16c",
              "lessThan": "445e4a1e6025ecd5312e9a95c1b234192c976ca1",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "5951fee46befbf6176c86482432f4f76e522f16c",
              "lessThan": "89c65ec3c18903de763cf567c96ab3ef60e5f3b0",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "5951fee46befbf6176c86482432f4f76e522f16c",
              "lessThan": "85171332742e741ccd6f401c69b6e0d698119e72",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "fs/f2fs/file.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.16",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.16",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.51",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.5",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/445e4a1e6025ecd5312e9a95c1b234192c976ca1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/85171332742e741ccd6f401c69b6e0d698119e72",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/89c65ec3c18903de763cf567c96ab3ef60e5f3b0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}