CVEvulnerability
CVE-2026-68083
9.1 CRITICAL
Official page ↗
- Status
- Received
- Published
- 2026-08-10
- Last modified
- 2026-10-30
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 9.1 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
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.
References
- https://git.kernel.org/stable/c/1c8951963d8ed357f70f59e0ad4ddce2199d2016 git.kernel.org
- https://git.kernel.org/stable/c/489d1ded01425c0fb33418172c0e4e588467526b git.kernel.org
- https://git.kernel.org/stable/c/98185b3025beeae92d1fe700d5db26b9ac4bf025 git.kernel.org
- https://git.kernel.org/stable/c/a2516be69048856e2a49a51e00975dc59431f95c git.kernel.org
- https://git.kernel.org/stable/c/c7c884a1305aa4540eb7942a50bd356b34120e1f git.kernel.org
- https://git.kernel.org/stable/c/f1f53dc95edfb3d2072e5e8cd8eb9a2fe7d7f2d0 git.kernel.org