{"id":"CVE-2026-53017","title":"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 writt…","summary":"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 writt…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 3.8, < 7.0.10"],"patched":["linux_kernel 7.0.10"],"published":"2026-06-24","updated":"2026-10-15","sourceUpdated":"2026-10-15T11:17:36.123","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53017","references":[{"url":"https://git.kernel.org/stable/c/20cedb4d9f6b230d0ee469690b8f868f06a07c29","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/238e14eb7226f883b72caccd2d37bf5707df066b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cb06a07d835ba1ea250785a796243bb483e65816","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/0645fa4d48e9b77d93f8b7a1c1fea58a97c2f8b0"},{"url":"https://git.kernel.org/stable/c/9fd3bcb54a6afea5fa8a828d010561143560b7c5"}],"tags":["nvd","cve.org"],"epss":0.00162,"epssPercentile":0.05311,"ingestedAt":"2026-07-11T19:15:11.809Z","slug":"CVE-2026-53017","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `linux_kernel >= 3.8, < 7.0.10`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.0.10`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":222308,"id":"CVE-2026-53017","ts":1792065874264,"field":"cvss","old":null,"new":"5.5"},{"seq":222307,"id":"CVE-2026-53017","ts":1792065874264,"field":"severity","old":"none","new":"medium"}]}