CVE-2026-46175
HighCVSS 7.1Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
A vulnerability has been identified in the Linux kernel related to node block migration in the f2fs filesystem, which may lead to misinterpretation of data as fsync-written. This issue occurs during FGGC node block migration, potentially resulting in errors in the fsck tool.
Risk Assessment
Organizations may encounter data integrity issues, which could lead to data loss or incorrect information about the filesystem state. Improper functioning of filesystem checking tools may impact the availability and reliability of systems.
Recommendation
It is recommended to update the Linux kernel to the latest version to eliminate this vulnerability and ensure proper handling of node block migration in the f2fs filesystem.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix fsck inconsistency caused by FGGC of node block During FGGC node block migration, fsck may incorrectly treat the migrated node block as fsync-written data. The reproduction scenario: root@vm:/mnt/f2fs# seq 1 2048 | xargs -n 1 ./test_sync // write inline inode and sync root@vm:/mnt/f2fs# rm -f 1 root@vm:/mnt/f2fs# sync root@vm:/mnt/f2fs# f2fs_io gc_range // move data block in sync mode and not write CP SPO, "fsck --dry-run" find inode has already checkpointed but still with DENT_BIT_SHIFT set The root cause is that GC does not clear the dentry mark and fsync mark during node block migration, leading fsck to misinterpret them as user-issued fsync writes. In BGGC mode, node block migration is handled by f2fs_sync_node_pages(), which guarantees the dentry and fsync marks are cleared before writing. This patch move the set/clear of the fsync|dentry marks into __write_node_folio to make the logic clearer, and ensures the fsync|dentry mark is cleared in FGGC.