[src/trunk]: src/lib/libc/stdlib Correct handling of minval > maxval in strto...

[kamil <kamil%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/274779e50e43
branches:  trunk
changeset: 837468:274779e50e43
user:      kamil <kamil%NetBSD.org@localhost>
date:      Thu Dec 06 06:29:56 2018 +0000

description:
Correct handling of minval > maxval in strtonum(3)

The original implementation in OpenBSD returns "invalid" and avoids reading
the input string. The replaced behavior was interpreting the input string
ignoring the invalid arguments.

diffstat:

 lib/libc/stdlib/strtonum.c |  9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diffs (30 lines):

diff -r d43b8ae079b2 -r 274779e50e43 lib/libc/stdlib/strtonum.c
--- a/lib/libc/stdlib/strtonum.c        Thu Dec 06 01:42:20 2018 +0000
+++ b/lib/libc/stdlib/strtonum.c        Thu Dec 06 06:29:56 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: strtonum.c,v 1.5 2018/01/04 20:57:29 kamil Exp $       */
+/*     $NetBSD: strtonum.c,v 1.6 2018/12/06 06:29:56 kamil Exp $       */
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
  * All rights reserved.
@@ -29,7 +29,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: strtonum.c,v 1.5 2018/01/04 20:57:29 kamil Exp $");
+__RCSID("$NetBSD: strtonum.c,v 1.6 2018/12/06 06:29:56 kamil Exp $");
 
 #include "namespace.h"
 
@@ -50,6 +50,11 @@
        if (errstr == NULL)
                errstr = &resp;
 
+       if (minval > maxval) {
+               *errstr = "invalid";
+               return 0;
+       }
+
        rv = (long long)strtoi(nptr, NULL, 10, minval, maxval, &e);
 
        if (e == 0) {