--- rpc/rpcsec_gss/svc_rpcsec_gss.c	2019-02-08 19:19:29.390541000 -0500
+++ rpc/rpcsec_gss/svc_rpcsec_gss.c	2019-02-08 19:46:56.614047000 -0500
@@ -794,12 +794,15 @@ svc_rpc_gss_build_ucred(struct svc_rpc_g
 	uc->gidlist = client->cl_gid_storage;
 
 	numgroups = NGROUPS;
-	maj_stat = gss_pname_to_unix_cred(&min_stat, name, client->cl_mech,
-	    &uc->uid, &uc->gid, &numgroups, &uc->gidlist[0]);
-	if (GSS_ERROR(maj_stat))
+	if (name != NULL) {
+		maj_stat = gss_pname_to_unix_cred(&min_stat, name, client->cl_mech,
+		    &uc->uid, &uc->gid, &numgroups, &uc->gidlist[0]);
+		if (GSS_ERROR(maj_stat))
+			uc->gidlen = 0;
+		else
+			uc->gidlen = numgroups;
+	} else
 		uc->gidlen = 0;
-	else
-		uc->gidlen = numgroups;
 }
 
 static void
@@ -954,20 +957,24 @@ svc_rpc_gss_accept_sec_context(struct sv
 		 */
 		client->cl_rawcred.version = RPCSEC_GSS_VERSION;
 		rpc_gss_oid_to_mech(mech, &client->cl_rawcred.mechanism);
-		maj_stat = gss_export_name(&min_stat, client->cl_cname,
-		    &export_name);
-		if (maj_stat != GSS_S_COMPLETE) {
-			rpc_gss_log_status("gss_export_name", client->cl_mech,
-			    maj_stat, min_stat);
-			return (FALSE);
-		}
-		client->cl_rawcred.client_principal =
-			mem_alloc(sizeof(*client->cl_rawcred.client_principal)
-			    + export_name.length);
-		client->cl_rawcred.client_principal->len = export_name.length;
-		memcpy(client->cl_rawcred.client_principal->name,
-		    export_name.value, export_name.length);
-		gss_release_buffer(&min_stat, &export_name);
+		if (client->cl_cname != NULL) {
+			maj_stat = gss_export_name(&min_stat, client->cl_cname,
+			    &export_name);
+			if (maj_stat != GSS_S_COMPLETE) {
+				rpc_gss_log_status("gss_export_name", client->cl_mech,
+				    maj_stat, min_stat);
+				return (FALSE);
+			}
+			client->cl_rawcred.client_principal =
+				mem_alloc(sizeof(*client->cl_rawcred.client_principal)
+				    + export_name.length);
+			client->cl_rawcred.client_principal->len = export_name.length;
+			memcpy(client->cl_rawcred.client_principal->name,
+			    export_name.value, export_name.length);
+			gss_release_buffer(&min_stat, &export_name);
+		} else
+			KASSERT(client->cl_rawcred.client_principal == NULL,
+			    ("cl_rawcred.client_principal should be NULL"));
 		client->cl_rawcred.svc_principal =
 			client->cl_sname->sn_principal;
 		client->cl_rawcred.service = gc->gc_svc;
@@ -978,7 +985,8 @@ svc_rpc_gss_accept_sec_context(struct sv
 		 */
 		svc_rpc_gss_build_ucred(client, client->cl_cname);
 		svc_rpc_gss_set_flavor(client);
-		gss_release_name(&min_stat, &client->cl_cname);
+		if (client->cl_cname != NULL)
+			gss_release_name(&min_stat, &client->cl_cname);
 
 #ifdef DEBUG
 		{
@@ -986,11 +994,17 @@ svc_rpc_gss_accept_sec_context(struct sv
 
 			gss_oid_to_str(&min_stat, mech, &mechname);
 			
-			rpc_gss_log_debug("accepted context for %s with "
-			    "<mech %.*s, qop %d, svc %d>",
-			    client->cl_rawcred.client_principal->name,
-			    mechname.length, (char *)mechname.value,
-			    client->cl_qop, client->cl_rawcred.service);
+			if (client->cl_rawcred.client_principal != NULL)
+				rpc_gss_log_debug("accepted context for %s with "
+				    "<mech %.*s, qop %d, svc %d>",
+				    client->cl_rawcred.client_principal->name,
+				    mechname.length, (char *)mechname.value,
+				    client->cl_qop, client->cl_rawcred.service);
+			else
+				rpc_gss_log_debug("accepted context for no principal with "
+				    "<mech %.*s, qop %d, svc %d>",
+				    mechname.length, (char *)mechname.value,
+				    client->cl_qop, client->cl_rawcred.service);
 
 			gss_release_buffer(&min_stat, &mechname);
 		}