CVE-2025-71069

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

f2fs: invalidate dentry cache on failed whiteout creation

F2FS can mount filesystems with corrupted directory depth values that

get runtime-clamped to MAX_DIR_HASH_DEPTH. When RENAME_WHITEOUT

operations are performed on such directories, f2fs_rename performs

directory modifications (updating target entry and deleting source

entry) before attempting to add the whiteout entry via f2fs_add_link.

If f2fs_add_link fails due to the corrupted directory structure, the

function returns an error to VFS, but the partial directory

modifications have already been committed to disk. VFS assumes the

entire rename operation failed and does not update the dentry cache,

leaving stale mappings.

In the error path, VFS does not call d_move() to update the dentry

cache. This results in new_dentry still pointing to the old inode

(new_inode) which has already had its i_nlink decremented to zero.

The stale cache causes subsequent operation

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References