CVE-2026-31709 smb: client: validate the whole DACL before rewriting it in cifsacl

In the Linux kernel, the following vulnerability has been resolved: smb: client: validate the whole DACL before rewriting it in cifsacl buildsecdesc and idmodetocifsacl derive a DACL pointer from a server-supplied dacloffset and then use the incoming ACL to rebuild the chmod/chown security...