Paper/Archive/CVE-2026-68083

CVE-2026-68083

Linux Linux — ksmbd: fix path resolution in ksmbd_vfs_kern_path_create

Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
Linux265fd1991c1db85fbabaad4946ca0e63e2ae688d – < a2516be69048856e2a49a51e00975dc59431f95ca2516be69048856e2a49a51e00975dc59431f95cCNA
Linux265fd1991c1db85fbabaad4946ca0e63e2ae688d – < 489d1ded01425c0fb33418172c0e4e588467526b489d1ded01425c0fb33418172c0e4e588467526bCNA
Linux265fd1991c1db85fbabaad4946ca0e63e2ae688d – < c7c884a1305aa4540eb7942a50bd356b34120e1fc7c884a1305aa4540eb7942a50bd356b34120e1fCNA
Linux265fd1991c1db85fbabaad4946ca0e63e2ae688d – < 98185b3025beeae92d1fe700d5db26b9ac4bf02598185b3025beeae92d1fe700d5db26b9ac4bf025CNA
Linux265fd1991c1db85fbabaad4946ca0e63e2ae688d – < 1c8951963d8ed357f70f59e0ad4ddce2199d20161c8951963d8ed357f70f59e0ad4ddce2199d2016CNA
Linux5.15–CNA

Scores by source

Linux (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

References

refgit.kernel.org/stable/c/a2516be69048856e2a49a51e00975dc59431f95crefgit.kernel.org/stable/c/489d1ded01425c0fb33418172c0e4e588467526brefgit.kernel.org/stable/c/c7c884a1305aa4540eb7942a50bd356b34120e1frefgit.kernel.org/stable/c/98185b3025beeae92d1fe700d5db26b9ac4bf025refgit.kernel.org/stable/c/1c8951963d8ed357f70f59e0ad4ddce2199d2016