{"cve":"CVE-2026-53017","nvd":{"published":"2026-06-24T17:17:13.020","modified":"2026-10-21T13:19:08.850","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/0645fa4d48e9b77d93f8b7a1c1fea58a97c2f8b0","https://git.kernel.org/stable/c/20cedb4d9f6b230d0ee469690b8f868f06a07c29","https://git.kernel.org/stable/c/238e14eb7226f883b72caccd2d37bf5707df066b","https://git.kernel.org/stable/c/9fd3bcb54a6afea5fa8a828d010561143560b7c5","https://git.kernel.org/stable/c/cb06a07d835ba1ea250785a796243bb483e65816"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-53017","score":0.00162,"percentile":0.05306,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}