GHSA-9M9W-6GJG-9M6R

Vulnerability from github – Published: 2026-03-18 18:31 – Updated: 2026-03-18 18:31
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Details

In the Linux kernel, the following vulnerability has been resolved:

f2fs: fix IS_CHECKPOINTED flag inconsistency issue caused by concurrent atomic commit and checkpoint writes

During SPO tests, when mounting F2FS, an -EINVAL error was returned from f2fs_recover_inode_page. The issue occurred under the following scenario

Thread A Thread B f2fs_ioc_commit_atomic_write - f2fs_do_sync_file // atomic = true - f2fs_fsync_node_pages : last_folio = inode folio : schedule before folio_lock(last_folio) f2fs_write_checkpoint - block_operations// writeback last_folio - schedule before f2fs_flush_nat_entries : set_fsync_mark(last_folio, 1) : set_dentry_mark(last_folio, 1) : folio_mark_dirty(last_folio) - __write_node_folio(last_folio) : f2fs_down_read(&sbi->node_write)//block - f2fs_flush_nat_entries : {struct nat_entry}->flag |= BIT(IS_CHECKPOINTED) - unblock_operations : f2fs_up_write(&sbi->node_write) f2fs_write_checkpoint//return : f2fs_do_write_node_page() f2fs_ioc_commit_atomic_write//return SPO

Thread A calls f2fs_need_dentry_mark(sbi, ino), and the last_folio has already been written once. However, the {struct nat_entry}->flag did not have the IS_CHECKPOINTED set, causing set_dentry_mark(last_folio, 1) and write last_folio again after Thread B finishes f2fs_write_checkpoint.

After SPO and reboot, it was detected that {struct node_info}->blk_addr was not NULL_ADDR because Thread B successfully write the checkpoint.

This issue only occurs in atomic write scenarios. For regular file fsync operations, the folio must be dirty. If block_operations->f2fs_sync_node_pages successfully submit the folio write, this path will not be executed. Otherwise, the f2fs_write_checkpoint will need to wait for the folio write submission to complete, as sbi->nr_pages[F2FS_DIRTY_NODES] > 0. Therefore, the situation where f2fs_need_dentry_mark checks that the {struct nat_entry}->flag /wo the IS_CHECKPOINTED flag, but the folio write has already been submitted, will not occur.

Therefore, for atomic file fsync, sbi->node_write should be acquired through __write_node_folio to ensure that the IS_CHECKPOINTED flag correctly indicates that the checkpoint write has been completed.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-23267"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-18T18:16:25Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix IS_CHECKPOINTED flag inconsistency issue caused by concurrent atomic commit and checkpoint writes\n\nDuring SPO tests, when mounting F2FS, an -EINVAL error was returned from\nf2fs_recover_inode_page. The issue occurred under the following scenario\n\nThread A                                     Thread B\nf2fs_ioc_commit_atomic_write\n - f2fs_do_sync_file // atomic = true\n  - f2fs_fsync_node_pages\n    : last_folio = inode folio\n    : schedule before folio_lock(last_folio) f2fs_write_checkpoint\n                                              - block_operations// writeback last_folio\n                                              - schedule before f2fs_flush_nat_entries\n    : set_fsync_mark(last_folio, 1)\n    : set_dentry_mark(last_folio, 1)\n    : folio_mark_dirty(last_folio)\n    - __write_node_folio(last_folio)\n      : f2fs_down_read(\u0026sbi-\u003enode_write)//block\n                                              - f2fs_flush_nat_entries\n                                                : {struct nat_entry}-\u003eflag |= BIT(IS_CHECKPOINTED)\n                                              - unblock_operations\n                                                : f2fs_up_write(\u0026sbi-\u003enode_write)\n                                             f2fs_write_checkpoint//return\n      : f2fs_do_write_node_page()\nf2fs_ioc_commit_atomic_write//return\n                                             SPO\n\nThread A calls f2fs_need_dentry_mark(sbi, ino), and the last_folio has\nalready been written once. However, the {struct nat_entry}-\u003eflag did not\nhave the IS_CHECKPOINTED set, causing set_dentry_mark(last_folio, 1) and\nwrite last_folio again after Thread B finishes f2fs_write_checkpoint.\n\nAfter SPO and reboot, it was detected that {struct node_info}-\u003eblk_addr\nwas not NULL_ADDR because Thread B successfully write the checkpoint.\n\nThis issue only occurs in atomic write scenarios. For regular file\nfsync operations, the folio must be dirty. If\nblock_operations-\u003ef2fs_sync_node_pages successfully submit the folio\nwrite, this path will not be executed. Otherwise, the\nf2fs_write_checkpoint will need to wait for the folio write submission\nto complete, as sbi-\u003enr_pages[F2FS_DIRTY_NODES] \u003e 0. Therefore, the\nsituation where f2fs_need_dentry_mark checks that the {struct\nnat_entry}-\u003eflag /wo the IS_CHECKPOINTED flag, but the folio write has\nalready been submitted, will not occur.\n\nTherefore, for atomic file fsync, sbi-\u003enode_write should be acquired\nthrough __write_node_folio to ensure that the IS_CHECKPOINTED flag\ncorrectly indicates that the checkpoint write has been completed.",
  "id": "GHSA-9m9w-6gjg-9m6r",
  "modified": "2026-03-18T18:31:18Z",
  "published": "2026-03-18T18:31:18Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23267"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/32bc3c9fe18881d50dd51fd5f26d19fe1190dc0d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/75e19da068adf0dc5dd269dd157392434b9117d4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7633a7387eb4d0259d6bea945e1d3469cd135bbc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/962c167b0f262b9962207fbeaa531721d55ea00e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bd66b4c487d5091d2a65d6089e0de36f0c26a4c7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ed81bc5885460905f9160e7b463e5708fd056324"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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