CVE-2026-53017

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix data loss caused by incorrect use of nat_entry flag Data loss can occur when fsync is performed on a newly created file (before any checkpoint has been written) concurrently with a checkpoint operation. 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_flush_nat_entries - f2fs_fsync_node_pages // no dirty node - f2fs_need_inode_block_update // return false SPO and lost 'file A' f2fs_flush_nat_entries() sets the IS_CHECKPOINTED and HAS_LAST_FSYNC flags for the nat_entry, but this does not mean that the checkpoint has actually completed successfully. However, f2fs_need_inode_block_update() checks these flags and incorrectly assumes that the checkpoint has finished. The root cause is that the semantics of IS_CHECKPOINTED and HAS_LAST_FSYNC are only guaranteed after the checkpoint write fully completes. This patch modifies f2fs_need_inode_block_update() to acquire the sbi->node_write lock before reading the nat_entry flags, ensuring that once IS_CHECKPOINTED and HAS_LAST_FSYNC are observed to be set, the checkpoint operation has already completed.

Severity

MEDIUM

CVSS score

5.5 (v3.1)

Vulnerability status

Modified

Source identifier

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

Published

2026-06-24 17:17:13.020000

Last modified

2026-10-30 13:19:08.543000

View original CVE JSON

{
  "id": "CVE-2026-53017",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-06-24T17:17:13.020",
  "lastModified": "2026-10-30T13:19:08.543",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix data loss caused by incorrect use of nat_entry flag\n\nData loss can occur when fsync is performed on a newly created file\n(before any checkpoint has been written) concurrently with a checkpoint\noperation. The scenario is as follows:\n\ncreate & write & fsync 'file A'                 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_flush_nat_entries\n - f2fs_fsync_node_pages // no dirty node\n - f2fs_need_inode_block_update // return false\n SPO and lost 'file A'\n\nf2fs_flush_nat_entries() sets the IS_CHECKPOINTED and HAS_LAST_FSYNC\nflags for the nat_entry, but this does not mean that the checkpoint has\nactually completed successfully. However, f2fs_need_inode_block_update()\nchecks these flags and incorrectly assumes that the checkpoint has\nfinished.\n\nThe root cause is that the semantics of IS_CHECKPOINTED and\nHAS_LAST_FSYNC are only guaranteed after the checkpoint write fully\ncompletes.\n\nThis patch modifies f2fs_need_inode_block_update() to acquire the\nsbi->node_write lock before reading the nat_entry flags, ensuring that\nonce IS_CHECKPOINTED and HAS_LAST_FSYNC are observed to be set, the\ncheckpoint operation has already completed."
    }
  ],
  "affected": [
    {
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      "affectedData": [
        {
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          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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            },
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              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
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              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
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              "version": "6.12.114",
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              "status": "unaffected"
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              "versionType": "original_commit_for_fix",
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  "metrics": {
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        "type": "Primary",
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          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
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    }
  ],
  "configurations": [
    {
      "nodes": [
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          "operator": "OR",
          "negate": false,
          "cpeMatch": [
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