CVE-2026-68083

/// Technical description

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

ksmbd: fix path resolution in ksmbd_vfs_kern_path_create

The SMB2 open lookup is rooted at the share with LOOKUP_BENEATH, but the

create/mkdir/hardlink sink is not: ksmbd_vfs_kern_path_create() builds an

absolute path with convert_to_unix_name() and resolves it from AT_FDCWD

via start_creating_path(), so a ".." component is walked from the real

filesystem root and escapes the export.

An authenticated client races a missing path component so the rooted open

lookup returns -ENOENT (taking the create branch) while the same component

is present (a directory) when the create walk runs; the create then

resolves ".." out of the share.

Root the create walk at the share like the lookup and rename paths already

are: resolve the parent with vfs_path_parent_lookup(..., LOOKUP_BENEATH,

&share_conf->vfs_path) and create the final component with

start_creating_noperm(). convert_to_unix_name() then has no callers and is

removed.

/// 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