diff -up Linux-PAM-1.1.8/modules/pam_unix/support.h.max-fd-no Linux-PAM-1.1.8/modules/pam_unix/support.h
--- Linux-PAM-1.1.8/modules/pam_unix/support.h.max-fd-no	2017-11-02 14:04:25.895425318 +0100
+++ Linux-PAM-1.1.8/modules/pam_unix/support.h	2019-08-06 14:46:59.237125151 +0200
@@ -141,7 +141,7 @@ static const UNIX_Ctrls unix_args[UNIX_C
 
 #define UNIX_DEFAULTS  (unix_args[UNIX__NONULL].flag)
 
-#define MAX_FD_NO 2000000
+#define MAX_FD_NO 65535
 
 /* use this to free strings. ESPECIALLY password strings */