CVE-2026-53168

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

fuse: reject fuse_notify() pagecache ops on directories

The operations FUSENOTIFYSTORE and FUSENOTIFYRETRIEVE allow the FUSE daemon to actively write/read pagecache contents.

For directories with FOPENCACHEDIR, the pagecache is used as kernel-internal cache storage, and userspace is not supposed to have direct access to this cache - in particular, fuseparsecache() will hit WARN_ON() if the cache contains bogus data.

Reject FUSENOTIFYSTORE and FUSENOTIFYRETRIEVE on anything other than regular files with -EINVAL.