Linux KernelOperating system · Linux
CVE-2026-53017
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA race condition in f2fs filesystem allows data loss when fsync is performed on a newly created file concurrently with checkpoint. The function f2fs_need_inode_block_update() incorrectly relies on IS_CHECKPOINTED and HAS_LAST_FSYNC nat_entry flags set during checkpoint to determine if inode blocks need updating, but these flags don't guarantee the checkpoint has actually completed. The fix acquires sbi->node_write lock before reading these flags.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Linux KernelOperating system
>= 3.8, < 7.0.10CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify if f2fs filesystem is in useCheck mounted filesystems: mount | grep f2fs or cat /proc/mounts | grep f2fsAffected if No f2fs partitions are mounted - the system is not using the affected filesystem
-
Check the running kernel versionRun 'uname -r' and compare the version number against the affected range (>= 3.8 and < 7.0.10)Affected if Kernel version falls within 3.8 to 7.0.9 inclusive
-
Verify f2fs module statusCheck if f2fs module is loaded: lsmod | grep f2fs or check /proc/filesystems for f2fs supportAffected if f2fs is not loaded or compiled into the kernel - the vulnerable code path is not reachable
-
Determine if workloads involve fsync on newly created filesReview application I/O patterns; check if any workloads perform fsync() on newly created files on f2fs partitionsAffected if No applications perform fsync on newly created f2fs files - the race condition cannot be triggered
The system is affected if it runs a kernel between 3.8 and 7.0.9 inclusive, uses f2fs filesystem, and has workloads that perform fsync on newly created files concurrently with checkpoint operations.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped7.0.10
Apply the upstream kernel patch to f2fs_need_inode_block_update() to acquire node_write lock before reading nat_entry flags, ensuring checkpoint completion is properly synchronized.
Linux Kernel 7.0.10 or later
- Upgrade the Linux kernel to version 7.0.10 or later to resolve the f2fs data loss vulnerability
- Alternatively, apply the vendor patch that modifies f2fs_need_inode_block_update() to acquire sbi->node_write lock before reading nat_entry flags (IS_CHECKPOINTED and HAS_LAST_FSYNC)
- After upgrading or patching, verify the f2fs filesystem integrity using fsck.f2fs or mount with check=strict mode
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Linux Kernel
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,520.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-53017 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-53017 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data