v4.19.13 snapshot.
diff --git a/net/sunrpc/auth_null.c b/net/sunrpc/auth_null.c
new file mode 100644
index 0000000..4b48228
--- /dev/null
+++ b/net/sunrpc/auth_null.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/net/sunrpc/auth_null.c
+ *
+ * AUTH_NULL authentication. Really :-)
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/sunrpc/clnt.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY RPCDBG_AUTH
+#endif
+
+static struct rpc_auth null_auth;
+static struct rpc_cred null_cred;
+
+static struct rpc_auth *
+nul_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
+{
+ atomic_inc(&null_auth.au_count);
+ return &null_auth;
+}
+
+static void
+nul_destroy(struct rpc_auth *auth)
+{
+}
+
+/*
+ * Lookup NULL creds for current process
+ */
+static struct rpc_cred *
+nul_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
+{
+ if (flags & RPCAUTH_LOOKUP_RCU)
+ return &null_cred;
+ return get_rpccred(&null_cred);
+}
+
+/*
+ * Destroy cred handle.
+ */
+static void
+nul_destroy_cred(struct rpc_cred *cred)
+{
+}
+
+/*
+ * Match cred handle against current process
+ */
+static int
+nul_match(struct auth_cred *acred, struct rpc_cred *cred, int taskflags)
+{
+ return 1;
+}
+
+/*
+ * Marshal credential.
+ */
+static __be32 *
+nul_marshal(struct rpc_task *task, __be32 *p)
+{
+ *p++ = htonl(RPC_AUTH_NULL);
+ *p++ = 0;
+ *p++ = htonl(RPC_AUTH_NULL);
+ *p++ = 0;
+
+ return p;
+}
+
+/*
+ * Refresh credential. This is a no-op for AUTH_NULL
+ */
+static int
+nul_refresh(struct rpc_task *task)
+{
+ set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
+ return 0;
+}
+
+static __be32 *
+nul_validate(struct rpc_task *task, __be32 *p)
+{
+ rpc_authflavor_t flavor;
+ u32 size;
+
+ flavor = ntohl(*p++);
+ if (flavor != RPC_AUTH_NULL) {
+ printk("RPC: bad verf flavor: %u\n", flavor);
+ return ERR_PTR(-EIO);
+ }
+
+ size = ntohl(*p++);
+ if (size != 0) {
+ printk("RPC: bad verf size: %u\n", size);
+ return ERR_PTR(-EIO);
+ }
+
+ return p;
+}
+
+const struct rpc_authops authnull_ops = {
+ .owner = THIS_MODULE,
+ .au_flavor = RPC_AUTH_NULL,
+ .au_name = "NULL",
+ .create = nul_create,
+ .destroy = nul_destroy,
+ .lookup_cred = nul_lookup_cred,
+};
+
+static
+struct rpc_auth null_auth = {
+ .au_cslack = NUL_CALLSLACK,
+ .au_rslack = NUL_REPLYSLACK,
+ .au_flags = RPCAUTH_AUTH_NO_CRKEY_TIMEOUT,
+ .au_ops = &authnull_ops,
+ .au_flavor = RPC_AUTH_NULL,
+ .au_count = ATOMIC_INIT(0),
+};
+
+static
+const struct rpc_credops null_credops = {
+ .cr_name = "AUTH_NULL",
+ .crdestroy = nul_destroy_cred,
+ .crbind = rpcauth_generic_bind_cred,
+ .crmatch = nul_match,
+ .crmarshal = nul_marshal,
+ .crrefresh = nul_refresh,
+ .crvalidate = nul_validate,
+};
+
+static
+struct rpc_cred null_cred = {
+ .cr_lru = LIST_HEAD_INIT(null_cred.cr_lru),
+ .cr_auth = &null_auth,
+ .cr_ops = &null_credops,
+ .cr_count = ATOMIC_INIT(1),
+ .cr_flags = 1UL << RPCAUTH_CRED_UPTODATE,
+};