[src/trunk]: src/lib/libcurses wtouchln - verify/clip input parameters

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

details:   https://anonhg.NetBSD.org/src/rev/02a774a018ae
branches:  trunk
changeset: 973551:02a774a018ae
user:      uwe <uwe%NetBSD.org@localhost>
date:      Fri Jul 03 23:28:51 2020 +0000

description:
wtouchln - verify/clip input parameters
>From Naman Jain in PR lib/55454

diffstat:

 lib/libcurses/touchwin.c |  13 +++++++++----
 1 files changed, 9 insertions(+), 4 deletions(-)

diffs (34 lines):

diff -r d8f3b6c2fc8c -r 02a774a018ae lib/libcurses/touchwin.c
--- a/lib/libcurses/touchwin.c  Fri Jul 03 22:40:55 2020 +0000
+++ b/lib/libcurses/touchwin.c  Fri Jul 03 23:28:51 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: touchwin.c,v 1.31 2019/04/24 07:09:44 blymn Exp $      */
+/*     $NetBSD: touchwin.c,v 1.32 2020/07/03 23:28:51 uwe Exp $        */
 
 /*
  * Copyright (c) 1981, 1993, 1994
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)touchwin.c 8.2 (Berkeley) 5/4/94";
 #else
-__RCSID("$NetBSD: touchwin.c,v 1.31 2019/04/24 07:09:44 blymn Exp $");
+__RCSID("$NetBSD: touchwin.c,v 1.32 2020/07/03 23:28:51 uwe Exp $");
 #endif
 #endif                         /* not lint */
 
@@ -177,8 +177,13 @@
        __CTRACE(__CTRACE_LINE, "wtouchln: (%p) %d, %d, %d\n",
            win, line, n, changed);
 #endif
-       if (line + n > win->maxy)
-               line = win->maxy - n;
+       if (line < 0 || win->maxy <= line)
+               return ERR;
+       if (n < 0)
+               return ERR;
+       if (n > win->maxy - line)
+               n = win->maxy - line;
+
        for (y = line; y < line + n; y++) {
                if (changed == 1)
                        _cursesi_touchline_force(win, y, 0,