cve-2026-64031

{
  "cvss": 7.8,
  "datePublished": "2026-07-19T16:17:43.250",
  "dateUpdated": "2026-09-14T12:17:43.927",
  "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: fix managed cache race for unaligned extents\n\nAfter unaligned compressed extents were introduced, the following race\ncould occur:\n\n[Thread 1]                                   [Thread 2]\n(z_erofs_fill_bio_vec)\n<handle a Z_EROFS_PREALLOCATED_FOLIO folio>\n...\nfilemap_add_folio (1)\n                                             (z_erofs_bind_cache)\n                                             <the same folio is found..>\n                                             ..\n                                             ..\nfolio_attach_private (2)\n                                             filemap_add_folio (3) again\n\nSince (1) is executed but (2) hasn't been executed yet, it's possible\nthat another thread finds the same managed folio in z_erofs_bind_cache()\nfor a different pcluster and calls filemap_add_folio() again since\nfolio->private is still Z_EROFS_PREALLOCATED_FOLIO.\n\nFix this by explicitly clearing folio->private before making the folio\nvisible in the managed cache so that another pcluster can simply wait\non the locked managed folio as what we did for other shared cases [1].\n\nThis only impacts unaligned data compression (`-E48bit` with zstd,\nfor example).\n\n[1] Commit 9e2f9d34dd12 (\"erofs: handle overlapped pclusters out of\n crafted images properly\") was originally introduced to handle crafted\n overlapped extents, but it addresses unaligned extents as well.",
  "id": "CVE-2026-64031",
  "raw": {
    "affected": [
      {
        "affectedData": [
          {
            "defaultStatus": "unaffected",
            "product": "Linux",
            "programFiles": [
              "fs/erofs/zdata.c"
            ],
            "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
            "vendor": "Linux",
            "versions": [
              {
                "lessThan": "2718cdb6db0fdbe375e61f2980aada27bafb323e",
                "status": "affected",
                "version": "722f0fcdb0bb7d12a5c6d9460b9a7de1f735f36d",
                "versionType": "git"
              },
              {
                "lessThan": "425d32d6288d7d845e486af9419bbedccd8c9103",
                "status": "affected",
                "version": "7361d1e3763baaf7b9349c576137851458ad38d1",
                "versionType": "git"
              },
              {
                "lessThan": "038166f873c4caf6e85cfd4ea0c5a5ba297b4e8b",
                "status": "affected",
                "version": "7361d1e3763baaf7b9349c576137851458ad38d1",
                "versionType": "git"
              },
              {
                "lessThan": "649932fc3815eda2f24eb4de4b3a5e94886ee0b9",
                "status": "affected",
                "version": "7361d1e3763baaf7b9349c576137851458ad38d1",
                "versionType": "git"
              }
            ]
          },
          {
            "defaultStatus": "affected",
            "product": "Linux",
            "programFiles": [
              "fs/erofs/zdata.c"
            ],
            "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
            "vendor": "Linux",
            "versions": [
              {
                "status": "affected",
                "version": "6.15"
              },
              {
                "lessThan": "6.15",
                "status": "unaffected",
                "version": "0",
                "versionType": "semver"
              },
              {
                "lessThanOrEqual": "6.18.*",
                "status": "unaffected",
                "version": "6.18.34",
                "versionType": "semver"
              },
              {
                "lessThanOrEqual": "7.0.*",
                "status": "unaffected",
                "version": "7.0.11",
                "versionType": "semver"
              },
              {
                "lessThanOrEqual": "*",
                "status": "unaffected",
                "version": "7.1",
                "versionType": "original_commit_for_fix"
              }
            ]
          }
        ],
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: fix managed cache race for unaligned extents\n\nAfter unaligned compressed extents were introduced, the following race\ncould occur:\n\n[Thread 1]                                   [Thread 2]\n(z_erofs_fill_bio_vec)\n<handle a Z_EROFS_PREALLOCATED_FOLIO folio>\n...\nfilemap_add_folio (1)\n                                             (z_erofs_bind_cache)\n                                             <the same folio is found..>\n                                             ..\n                                             ..\nfolio_attach_private (2)\n                                             filemap_add_folio (3) again\n\nSince (1) is executed but (2) hasn't been executed yet, it's possible\nthat another thread finds the same managed folio in z_erofs_bind_cache()\nfor a different pcluster and calls filemap_add_folio() again since\nfolio->private is still Z_EROFS_PREALLOCATED_FOLIO.\n\nFix this by explicitly clearing folio->private before making the folio\nvisible in the managed cache so that another pcluster can simply wait\non the locked managed folio as what we did for other shared cases [1].\n\nThis only impacts unaligned data compression (`-E48bit` with zstd,\nfor example).\n\n[1] Commit 9e2f9d34dd12 (\"erofs: handle overlapped pclusters out of\n crafted images properly\") was originally introduced to handle crafted\n overlapped extents, but it addresses unaligned extents as well."
      }
    ],
    "id": "CVE-2026-64031",
    "lastModified": "2026-09-14T12:17:43.927",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "exploitabilityScore": 1.8,
          "impactScore": 5.9,
          "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
          "type": "Secondary"
        }
      ]
    },
    "published": "2026-07-19T16:17:43.250",
    "references": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "url": "https://git.kernel.org/stable/c/038166f873c4caf6e85cfd4ea0c5a5ba297b4e8b"
      },
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "url": "https://git.kernel.org/stable/c/2718cdb6db0fdbe375e61f2980aada27bafb323e"
      },
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "url": "https://git.kernel.org/stable/c/425d32d6288d7d845e486af9419bbedccd8c9103"
      },
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "url": "https://git.kernel.org/stable/c/649932fc3815eda2f24eb4de4b3a5e94886ee0b9"
      }
    ],
    "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "vulnStatus": "Awaiting Analysis"
  },
  "severity": "HIGH",
  "source": "nvd",
  "title": "In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: fix managed cache race for unaligned exte..."
}