---
cve: "CVE-2026-53017"
severity: "LOW"
cvss: 3.1
epss: "11%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-06-24 17:17:13"
tags: [cve, security, low]
source: tsecurity.de CVE-Dossier
exported: "2026-09-19T18:11:21+02:00"
---

# CVE-2026-53017

> 3.1 LOW

## Beschreibung

In 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.

## Patch verfügbar (OSV)

- Kernel ≥ 7.0.10

## Referenzen

- <https://git.kernel.org/stable/c/20cedb4d9f6b230d0ee469690b8f868f06a07c29>
- <https://git.kernel.org/stable/c/238e14eb7226f883b72caccd2d37bf5707df066b>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-53017) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_