CVE-2025-68778

/// Technical description

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

btrfs: don't log conflicting inode if it's a dir moved in the current transaction

We can't log a conflicting inode if it's a directory and it was moved

from one parent directory to another parent directory in the current

transaction, as this can result an attempt to have a directory with

two hard links during log replay, one for the old parent directory and

another for the new parent directory.

The following scenario triggers that issue:

1) We have directories "dir1" and "dir2" created in a past transaction.

Directory "dir1" has inode A as its parent directory;

2) We move "dir1" to some other directory;

3) We create a file with the name "dir1" in directory inode A;

4) We fsync the new file. This results in logging the inode of the new file

and the inode for the directory "dir1" that was previously moved in the

current transaction. So the log tree has the INODE_REF item for the

new location of "dir1";

/// 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