diff -up shadow-4.1.5.1/lib/commonio.c.backup-mode shadow-4.1.5.1/lib/commonio.c

--- shadow-4.1.5.1/lib/commonio.c.backup-mode	2012-05-18 21:44:54.000000000 +0200

+++ shadow-4.1.5.1/lib/commonio.c	2012-09-19 20:27:16.089444234 +0200

@@ -301,15 +301,12 @@ static int create_backup (const char *ba

 	struct utimbuf ub;

 	FILE *bkfp;

 	int c;

-	mode_t mask;

 	if (fstat (fileno (fp), &sb) != 0) {

 		return -1;

 	}

-	mask = umask (077);

-	bkfp = fopen (backup, "w");

-	(void) umask (mask);

+	bkfp = fopen_set_perms (backup, "w", &sb);

 	if (NULL == bkfp) {

 		return -1;

 	}