[src/trunk]: src/usr.bin/look Properly check mmap(2) return value. We can end...

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

details:   https://anonhg.NetBSD.org/src/rev/e8876178166e
branches:  trunk
changeset: 821901:e8876178166e
user:      leot <leot%NetBSD.org@localhost>
date:      Tue Feb 21 09:23:31 2017 +0000

description:
Properly check mmap(2) return value. We can end up with a segmentation
fault if the user does not provide a regular file as look(1) file
argument.

Kindly reviewed by <Riastradh>

diffstat:

 usr.bin/look/look.c |  6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diffs (27 lines):

diff -r aa4cd395b3bc -r e8876178166e usr.bin/look/look.c
--- a/usr.bin/look/look.c       Tue Feb 21 08:40:16 2017 +0000
+++ b/usr.bin/look/look.c       Tue Feb 21 09:23:31 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: look.c,v 1.16 2012/02/23 22:57:53 joerg Exp $  */
+/*     $NetBSD: look.c,v 1.17 2017/02/21 09:23:31 leot Exp $   */
 
 /*-
  * Copyright (c) 1991, 1993
@@ -42,7 +42,7 @@
 #if 0
 static char sccsid[] = "@(#)look.c     8.2 (Berkeley) 5/4/95";
 #endif
-__RCSID("$NetBSD: look.c,v 1.16 2012/02/23 22:57:53 joerg Exp $");
+__RCSID("$NetBSD: look.c,v 1.17 2017/02/21 09:23:31 leot Exp $");
 #endif /* not lint */
 
 /*
@@ -147,7 +147,7 @@
                err(2, "%s", file);
        }
        if ((front = mmap(NULL, len,
-           PROT_READ, MAP_FILE|MAP_SHARED, fd, (off_t)0)) == NULL)
+           PROT_READ, MAP_FILE|MAP_SHARED, fd, (off_t)0)) == MAP_FAILED)
                err(2, "%s", file);
        back = front + len;
        exit(look(string, front, back));