CVE-2023-54313 ovl: fix null pointer dereference in ovl_get_acl_rcu()

In the Linux kernel, the following vulnerability has been resolved: ovl: fix null pointer dereference in ovlgetaclrcu Following process: P1 P2 pathopenat linkpathwalk maylookup inodepermissionrcu ovlpermission aclpermissioncheck checkacl getcachedaclrcu ovlgetinodeacl realinode =...