--- ./modules/pam_unix/passverify.c.orig	2021-07-21 10:03:55.199416508 +0200
+++ ./modules/pam_unix/passverify.c	2021-07-21 10:04:30.626880581 +0200
@@ -245,7 +245,7 @@
 			if (*spwdent == NULL) {
 #ifndef HELPER_COMPILE
 				/* still a chance the user can authenticate */
-				if (errno == EACCES || SELINUX_ENABLED)
+				if (geteuid() || SELINUX_ENABLED)
 					return PAM_UNIX_RUN_HELPER;
 #endif
 				return PAM_AUTHINFO_UNAVAIL;