{"id":"CVE-2026-53017","state":"PUBLISHED","title":"f2fs: fix data loss caused by incorrect use of nat_entry flag","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.","publishedAt":"2026-06-24T16:29:27.154Z","updatedAt":"2026-10-30T12:26:29.040Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e05df3b115e7308afbca652769b54e4549fcc723","status":"affected","lessThan":"eb65e8c7bd0a78a470cbdd3ff96232ba4a2ace89","versionType":"git"},{"version":"e05df3b115e7308afbca652769b54e4549fcc723","status":"affected","lessThan":"0645fa4d48e9b77d93f8b7a1c1fea58a97c2f8b0","versionType":"git"},{"version":"e05df3b115e7308afbca652769b54e4549fcc723","status":"affected","lessThan":"9fd3bcb54a6afea5fa8a828d010561143560b7c5","versionType":"git"},{"version":"e05df3b115e7308afbca652769b54e4549fcc723","status":"affected","lessThan":"cb06a07d835ba1ea250785a796243bb483e65816","versionType":"git"},{"version":"e05df3b115e7308afbca652769b54e4549fcc723","status":"affected","lessThan":"20cedb4d9f6b230d0ee469690b8f868f06a07c29","versionType":"git"},{"version":"e05df3b115e7308afbca652769b54e4549fcc723","status":"affected","lessThan":"238e14eb7226f883b72caccd2d37bf5707df066b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/node.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/node.c"]}],"references":["https://git.kernel.org/stable/c/eb65e8c7bd0a78a470cbdd3ff96232ba4a2ace89","https://git.kernel.org/stable/c/0645fa4d48e9b77d93f8b7a1c1fea58a97c2f8b0","https://git.kernel.org/stable/c/9fd3bcb54a6afea5fa8a828d010561143560b7c5","https://git.kernel.org/stable/c/cb06a07d835ba1ea250785a796243bb483e65816","https://git.kernel.org/stable/c/20cedb4d9f6b230d0ee469690b8f868f06a07c29","https://git.kernel.org/stable/c/238e14eb7226f883b72caccd2d37bf5707df066b"],"weaknesses":[],"ingestedAt":"2026-10-30T12:44:04.813Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53017.json","commit":"db8103c5921aac81d5d90efcf3745980dafabf49","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53017","state":"PUBLISHED","datePublished":"2026-06-24T16:29:27.154Z","dateUpdated":"2026-10-30T12:26:29.040Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.378Z"},"containers":{"cna":{"title":"f2fs: fix data loss caused by incorrect use of nat_entry flag","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e05df3b115e7308afbca652769b54e4549fcc723","status":"affected","lessThan":"eb65e8c7bd0a78a470cbdd3ff96232ba4a2ace89","versionType":"git"},{"version":"e05df3b115e7308afbca652769b54e4549fcc723","status":"affected","lessThan":"0645fa4d48e9b77d93f8b7a1c1fea58a97c2f8b0","versionType":"git"},{"version":"e05df3b115e7308afbca652769b54e4549fcc723","status":"affected","lessThan":"9fd3bcb54a6afea5fa8a828d010561143560b7c5","versionType":"git"},{"version":"e05df3b115e7308afbca652769b54e4549fcc723","status":"affected","lessThan":"cb06a07d835ba1ea250785a796243bb483e65816","versionType":"git"},{"version":"e05df3b115e7308afbca652769b54e4549fcc723","status":"affected","lessThan":"20cedb4d9f6b230d0ee469690b8f868f06a07c29","versionType":"git"},{"version":"e05df3b115e7308afbca652769b54e4549fcc723","status":"affected","lessThan":"238e14eb7226f883b72caccd2d37bf5707df066b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/node.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/node.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/eb65e8c7bd0a78a470cbdd3ff96232ba4a2ace89"},{"url":"https://git.kernel.org/stable/c/0645fa4d48e9b77d93f8b7a1c1fea58a97c2f8b0"},{"url":"https://git.kernel.org/stable/c/9fd3bcb54a6afea5fa8a828d010561143560b7c5"},{"url":"https://git.kernel.org/stable/c/cb06a07d835ba1ea250785a796243bb483e65816"},{"url":"https://git.kernel.org/stable/c/20cedb4d9f6b230d0ee469690b8f868f06a07c29"},{"url":"https://git.kernel.org/stable/c/238e14eb7226f883b72caccd2d37bf5707df066b"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:26:29.040Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}