The reported issue in the Linux kernel concerns the ksmbd SMB service’s handling of volume identifiers when responding to FS_OBJECT_ID_INFORMATION requests. The code originally relied on an incorrect source of volume data, and the new commit changes the logic to use the filesystem’s UUID (sb->s_uuid) as the primary identifier, falling back to the filesystem ID obtained from vfs_statfs() when a UUID is unavailable. This change is intended to correct the misuse of structure data that could result in malformed or duplicated volume identifiers being returned to SMB clients.

Administrators should note that all Linux kernels before the patch are affected. The fix is incorporated in the mainline kernel following commit 3a641257..., and applies to all releases that ship the kernel, including versions 7.0 RC1–RC4 and later stable releases. Anyone running a kernel that lacks the updated ksmbd logic is potentially exposed to the incorrect volume identifier behavior. Checking the kernel version and ensuring it includes the relevant commit is necessary for remediation.

The CVSS score assigned to this vulnerability is 5.5, reflecting a moderate impact. The EPSS score is less than 1 %, indicating a low probability that attackers will target this weakness. It is not listed in the CISA KEV catalog, and no public exploits have been reported. An attacker would need the ability to interact with the ksmbd service over SMB to provoke the flaw, which generally requires network or local access. Consequently, the risk is considered low to moderate, mainly concerning potential confusion or misidentification of shares rather than direct compromise.