Vulnerability-Lookup

FKIE_CVE-2026-53368

Vulnerability from fkie_nvd - Published: 2026-07-19 09:17 - Updated: 2026-07-29 16:55

Severity

7.1 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix fsck inconsistency caused by incorrect nat_entry flag usage f2fs_need_dentry_mark() reads nat_entry flags without mutual exclusion with the checkpoint path, which can result in an incorrect inode block marking state. The scenario is as follows: create & write & fsync 'file A' write checkpoint - f2fs_do_sync_file // inline inode - f2fs_write_inode // inode folio is dirty - f2fs_write_checkpoint - f2fs_flush_merged_writes - f2fs_sync_node_pages - f2fs_fsync_node_pages // no dirty node - f2fs_need_inode_block_update // return true - f2fs_fsync_node_pages // inode dirtied - f2fs_need_dentry_mark //return true - f2fs_flush_nat_entries - f2fs_write_checkpoint end - __write_node_folio // inode with DENT_BIT_SHIFT set SPO, "fsck --dry-run" find inode has already checkpointed but still with DENT_BIT_SHIFT set The state observed by f2fs_need_dentry_mark() can differ from the state observed in __write_node_folio() after acquiring sbi->node_write. The root cause is that the semantics of IS_CHECKPOINTED and HAS_FSYNCED_INODE are only guaranteed after the checkpoint write has fully completed. This patch moves set_dentry_mark() into __write_node_folio() and protects it with the sbi->node_write lock.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/019f9dda7f66e55eb94cd32e1d3fff5835f73fbc	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b28a83ea4934215b5de906c3ee4fbfbc651573e0	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/bedb710b63ae1bd617e65d0a8cf6cea1200b3753	Patch

Impacted products

	Vendor	Product	Version
	linux	linux_kernel	*
	linux	linux_kernel	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/f2fs/node.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "bedb710b63ae1bd617e65d0a8cf6cea1200b3753",
              "status": "affected",
              "version": "88bd02c9472a166b706284a34a84f1243322d782",
              "versionType": "git"
            },
            {
              "lessThan": "b28a83ea4934215b5de906c3ee4fbfbc651573e0",
              "status": "affected",
              "version": "88bd02c9472a166b706284a34a84f1243322d782",
              "versionType": "git"
            },
            {
              "lessThan": "019f9dda7f66e55eb94cd32e1d3fff5835f73fbc",
              "status": "affected",
              "version": "88bd02c9472a166b706284a34a84f1243322d782",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/f2fs/node.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.18"
            },
            {
              "lessThan": "3.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.30",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "1D338BAC-AB8F-4767-B816-F8E37E140F88",
              "versionEndExcluding": "6.18.30",
              "versionStartIncluding": "3.18",
              "vulnerable": true
            },
            {
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              "vulnerable": true
            }
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          "negate": false,
          "operator": "OR"
        }
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    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix fsck inconsistency caused by incorrect nat_entry flag usage\n\nf2fs_need_dentry_mark() reads nat_entry flags without mutual exclusion\nwith the checkpoint path, which can result in an incorrect inode block\nmarking state. The scenario is as follows:\n\ncreate \u0026 write \u0026 fsync \u0027file A\u0027                 write checkpoint\n- f2fs_do_sync_file // inline inode\n - f2fs_write_inode // inode folio is dirty\n                                                - f2fs_write_checkpoint\n                                                 - f2fs_flush_merged_writes\n                                                 - f2fs_sync_node_pages\n - f2fs_fsync_node_pages // no dirty node\n - f2fs_need_inode_block_update // return true\n - f2fs_fsync_node_pages // inode dirtied\n  - f2fs_need_dentry_mark //return true\n                                                 - f2fs_flush_nat_entries\n                                                - f2fs_write_checkpoint end\n  - __write_node_folio // inode with DENT_BIT_SHIFT set\n  SPO, \"fsck --dry-run\" find inode has already checkpointed but still\n  with DENT_BIT_SHIFT set\n\nThe state observed by f2fs_need_dentry_mark() can differ from the state\nobserved in __write_node_folio() after acquiring sbi-\u003enode_write. The\nroot cause is that the semantics of IS_CHECKPOINTED and\nHAS_FSYNCED_INODE are only guaranteed after the checkpoint write has\nfully completed.\n\nThis patch moves set_dentry_mark() into __write_node_folio() and\nprotects it with the sbi-\u003enode_write lock."
    }
  ],
  "id": "CVE-2026-53368",
  "lastModified": "2026-07-29T16:55:46.613",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-19T09:17:01.903",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/019f9dda7f66e55eb94cd32e1d3fff5835f73fbc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/b28a83ea4934215b5de906c3ee4fbfbc651573e0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/bedb710b63ae1bd617e65d0a8cf6cea1200b3753"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-53368 (GCVE-0-2026-53368)

Vulnerability from cvelistv5 – Published: 2026-07-19 09:10 – Updated: 2026-08-05 12:35

Title

f2fs: fix fsck inconsistency caused by incorrect nat_entry flag usage

Summary

Severity

7.1 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6992 records in the last 180 days details

References

3 references

URL	Tags
https://git.kernel.org/stable/c/bedb710b63ae1bd61…
https://git.kernel.org/stable/c/b28a83ea4934215b5…
https://git.kernel.org/stable/c/019f9dda7f66e55eb…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 88bd02c9472a166b706284a34a84f1243322d782 , < bedb710b63ae1bd617e65d0a8cf6cea1200b3753 (git) Affected: 88bd02c9472a166b706284a34a84f1243322d782 , < b28a83ea4934215b5de906c3ee4fbfbc651573e0 (git) Affected: 88bd02c9472a166b706284a34a84f1243322d782 , < 019f9dda7f66e55eb94cd32e1d3fff5835f73fbc (git)
Linux	Linux	Affected: 3.18 Unaffected: 0 , < 3.18 (semver) Unaffected: 6.18.30 , ≤ 6.18.* (semver) Unaffected: 7.0.7 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/f2fs/node.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "bedb710b63ae1bd617e65d0a8cf6cea1200b3753",
              "status": "affected",
              "version": "88bd02c9472a166b706284a34a84f1243322d782",
              "versionType": "git"
            },
            {
              "lessThan": "b28a83ea4934215b5de906c3ee4fbfbc651573e0",
              "status": "affected",
              "version": "88bd02c9472a166b706284a34a84f1243322d782",
              "versionType": "git"
            },
            {
              "lessThan": "019f9dda7f66e55eb94cd32e1d3fff5835f73fbc",
              "status": "affected",
              "version": "88bd02c9472a166b706284a34a84f1243322d782",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/f2fs/node.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.18"
            },
            {
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.30",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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                {
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix fsck inconsistency caused by incorrect nat_entry flag usage\n\nf2fs_need_dentry_mark() reads nat_entry flags without mutual exclusion\nwith the checkpoint path, which can result in an incorrect inode block\nmarking state. The scenario is as follows:\n\ncreate \u0026 write \u0026 fsync \u0027file A\u0027                 write checkpoint\n- f2fs_do_sync_file // inline inode\n - f2fs_write_inode // inode folio is dirty\n                                                - f2fs_write_checkpoint\n                                                 - f2fs_flush_merged_writes\n                                                 - f2fs_sync_node_pages\n - f2fs_fsync_node_pages // no dirty node\n - f2fs_need_inode_block_update // return true\n - f2fs_fsync_node_pages // inode dirtied\n  - f2fs_need_dentry_mark //return true\n                                                 - f2fs_flush_nat_entries\n                                                - f2fs_write_checkpoint end\n  - __write_node_folio // inode with DENT_BIT_SHIFT set\n  SPO, \"fsck --dry-run\" find inode has already checkpointed but still\n  with DENT_BIT_SHIFT set\n\nThe state observed by f2fs_need_dentry_mark() can differ from the state\nobserved in __write_node_folio() after acquiring sbi-\u003enode_write. The\nroot cause is that the semantics of IS_CHECKPOINTED and\nHAS_FSYNCED_INODE are only guaranteed after the checkpoint write has\nfully completed.\n\nThis patch moves set_dentry_mark() into __write_node_folio() and\nprotects it with the sbi-\u003enode_write lock."
        }
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            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The bug is reached via local filesystem syscalls (fsync/fdatasync on a writable file) on an F2FS mount. F2FS is primarily deployed on local flash storage (Android /data, ChromeOS, embedded), not as a network-facing attack surface.\nAC:L - An attacker controls both sides of the race by concurrently fsyncing an inline inode while triggering a checkpoint (e.g., via sync(2), heavy writeback, or background checkpoint/GC threads). No conditions outside attacker influence are required beyond routine concurrent I/O.\nPR:L - Exploitation requires only unprivileged write access to files on the F2FS filesystem plus the ability to issue fsync/sync syscalls. No CAP_SYS_ADMIN, mount privileges, or init-namespace root are needed.\nUI:N - No victim interaction is required; the attacker performs the write and fsync operations on files they can already modify.\nS:U - The impact is confined to F2FS on-disk metadata and recovery semantics within the same kernel/filesystem security boundary. There is no VM escape, sandbox breakout, or cross-authority boundary crossing.\nC:N - The bug causes incorrect setting of the DENT_BIT_SHIFT recovery flag on a node block. It does not read kernel memory, leak pointers, or disclose data beyond what the attacker already wrote.\nI:H - The race writes incorrect dentry recovery metadata to disk (checkpointed inode still marked with DENT_BIT_SHIFT), producing fsck-detectable filesystem inconsistency and potentially breaking roll-forward recovery of fsynced data after sudden power-off.\nA:H - Corrupted recovery metadata can cause mount-time recovery failures (as seen in the related atomic-write variant returning -EINVAL from f2fs_recover_inode_page) and fsck-detected inconsistency after power loss, degrading filesystem availability on F2FS-backed systems such as Android devices."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:35:15.297Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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        },
        {
          "url": "https://git.kernel.org/stable/c/019f9dda7f66e55eb94cd32e1d3fff5835f73fbc"
        }
      ],
      "title": "f2fs: fix fsck inconsistency caused by incorrect nat_entry flag usage",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-53368",
    "datePublished": "2026-07-19T09:10:29.573Z",
    "dateReserved": "2026-06-09T07:44:35.400Z",
    "dateUpdated": "2026-08-05T12:35:15.297Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

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.

Vulnerability timeline

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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