GHSA-F2M7-5M7M-7G2C
Vulnerability from github – Published: 2026-06-24 18:32 – Updated: 2026-06-24 18:32In 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.
{
"affected": [],
"aliases": [
"CVE-2026-53017"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-24T17:17:13Z",
"severity": null
},
"details": "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 \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_flush_nat_entries\n - f2fs_fsync_node_pages // no dirty node\n - f2fs_need_inode_block_update // return false\n SPO and lost \u0027file A\u0027\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-\u003enode_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.",
"id": "GHSA-f2m7-5m7m-7g2c",
"modified": "2026-06-24T18:32:43Z",
"published": "2026-06-24T18:32:43Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53017"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/20cedb4d9f6b230d0ee469690b8f868f06a07c29"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/238e14eb7226f883b72caccd2d37bf5707df066b"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
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Nomenclature
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