In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix legacy client tracking initialization
Get rid of the nfsd4_legacy_tracking_ops->init() call in check_for_legacy_methods(). That will be handled in the caller (nfsd4_client_tracking_init()). Otherwise, we'll wind up calling nfsd4_legacy_tracking_ops->init() twice, and the second time we'll trigger the BUG_ON() in nfsd4_init_recdir().