In the Linux kernel, the following vulnerability has been resolved:
landlock: Fix d_parent walk
The WARNONONCE() in collectdomainaccesses() can be triggered when trying to link a root mount point. This cannot work in practice because this directory is mounted, but the VFS check is done after the call to securitypathlink().
Do not use source directory's d_parent when the source directory is the mount point.
[mic: Fix commit message]