watch for slimy link races, improvement by das33@cornell.edu & i

diff --git a/usr.bin/chpass/edit.c b/usr.bin/chpass/edit.c
index 3cab39c..43c16e3 100644 (file)
--- a/usr.bin/chpass/edit.c
+++ b/usr.bin/chpass/edit.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: edit.c,v 1.5 1996/08/26 22:55:37 deraadt Exp $        */
+/*     $OpenBSD: edit.c,v 1.6 1996/08/30 13:29:12 deraadt Exp $        */
 /*     $NetBSD: edit.c,v 1.6 1996/05/15 21:50:45 jtc Exp $     */
 
 /*-
@@ -38,7 +38,7 @@
 #if 0
 static char sccsid[] = "@(#)edit.c     8.3 (Berkeley) 4/2/94";
 #else
-static char rcsid[] = "$OpenBSD: edit.c,v 1.5 1996/08/26 22:55:37 deraadt Exp $";
+static char rcsid[] = "$OpenBSD: edit.c,v 1.6 1996/08/30 13:29:12 deraadt Exp $";
 #endif
 #endif /* not lint */
 
@@ -66,10 +66,10 @@ edit(tempname, pw)
        struct stat begin, end;
 
        for (;;) {
-               if (stat(tempname, &begin))
+               if (lstat(tempname, &begin) == -1 || S_ISLNK(begin.st_mode))
                        pw_error(tempname, 1, 1);
                pw_edit(1, tempname);
-               if (stat(tempname, &end))
+               if (lstat(tempname, &end) == -1 || S_ISLNK(begin.st_mode))
                        pw_error(tempname, 1, 1);
                if (begin.st_mtime == end.st_mtime) {
                        warnx("no changes made");