CVE-2026-68083

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

ksmbd: fix path resolution in ksmbdvfskernpathcreate

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

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

absolute path with converttounixname() and resolves it from ATFDCWD

via startcreatingpath(), 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 vfspathparentlookup(..., LOOKUPBENEATH,

&shareconf->vfspath) and create the final component with

startcreatingnoperm(). converttounix_name() then has no callers and is

removed.