[src/trunk]: src/usr.bin/make Guarantee no arithmetic overflow.

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

details:   https://anonhg.NetBSD.org/src/rev/6b3ed4a8a250
branches:  trunk
changeset: 352985:6b3ed4a8a250
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Apr 16 21:03:13 2017 +0000

description:
Guarantee no arithmetic overflow.

diffstat:

 usr.bin/make/parse.c |  13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)

diffs (50 lines):

diff -r b188f916109c -r 6b3ed4a8a250 usr.bin/make/parse.c
--- a/usr.bin/make/parse.c      Sun Apr 16 20:59:04 2017 +0000
+++ b/usr.bin/make/parse.c      Sun Apr 16 21:03:13 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: parse.c,v 1.220 2017/04/16 20:00:58 maya Exp $ */
+/*     $NetBSD: parse.c,v 1.221 2017/04/16 21:03:13 riastradh Exp $    */
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -69,14 +69,14 @@
  */
 
 #ifndef MAKE_NATIVE
-static char rcsid[] = "$NetBSD: parse.c,v 1.220 2017/04/16 20:00:58 maya Exp $";
+static char rcsid[] = "$NetBSD: parse.c,v 1.221 2017/04/16 21:03:13 riastradh Exp $";
 #else
 #include <sys/cdefs.h>
 #ifndef lint
 #if 0
 static char sccsid[] = "@(#)parse.c    8.3 (Berkeley) 3/19/94";
 #else
-__RCSID("$NetBSD: parse.c,v 1.220 2017/04/16 20:00:58 maya Exp $");
+__RCSID("$NetBSD: parse.c,v 1.221 2017/04/16 21:03:13 riastradh Exp $");
 #endif
 #endif /* not lint */
 #endif
@@ -129,6 +129,7 @@
 #include <assert.h>
 #include <ctype.h>
 #include <errno.h>
+#include <limits.h>
 #include <stdarg.h>
 #include <stdio.h>
 
@@ -548,9 +549,15 @@
        while (1) {
                assert(bufpos <= lf->len);
                if (bufpos == lf->len) {
+                       if (lf->len > SIZE_MAX/2) {
+                               errno = EFBIG;
+                               Error("%s: file too large", path);
+                               exit(1);
+                       }
                        lf->len *= 2;
                        lf->buf = bmake_realloc(lf->buf, lf->len);
                }
+               assert(bufpos < lf->len);
                result = read(fd, lf->buf + bufpos, lf->len - bufpos);
                if (result < 0) {
                        Error("%s: read error: %s", path, strerror(errno));