CVE-2024-46690

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

nfsd: fix nfsd4deleggetattr_conflict in presence of third party lease

It is not safe to dereference fl->c.flcowner without first confirming fl->fllmops is the expected manager. nfsd4deleggetattrconflict() tests fllmops but largely ignores the result and assumes that flcowner is an nfs4delegation anyway. This is wrong.

With this patch we restore the "!= &nfsdleasemng_ops" case to behave as it did before the change mentioned below. This is the same as the current code, but without any reference to a possible delegation.