FKIE_CVE-2026-23267
Vulnerability from fkie_nvd - Published: 2026-03-18 18:16 - Updated: 2026-03-19 13:25
Severity ?
Summary
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.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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": "CVE-2026-23267",
"lastModified": "2026-03-19T13:25:00.570",
"metrics": {},
"published": "2026-03-18T18:16:25.573",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/32bc3c9fe18881d50dd51fd5f26d19fe1190dc0d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/75e19da068adf0dc5dd269dd157392434b9117d4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7633a7387eb4d0259d6bea945e1d3469cd135bbc"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/962c167b0f262b9962207fbeaa531721d55ea00e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/bd66b4c487d5091d2a65d6089e0de36f0c26a4c7"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ed81bc5885460905f9160e7b463e5708fd056324"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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Sightings
| Author | Source | Type | Date |
|---|
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.
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