[src/trunk]: src/external/bsd/top/dist/machine Fix read of unitialized array ...

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

details:   https://anonhg.NetBSD.org/src/rev/791fea895649
branches:  trunk
changeset: 319480:791fea895649
user:      kamil <kamil%NetBSD.org@localhost>
date:      Thu May 31 10:14:21 2018 +0000

description:
Fix read of unitialized array elements in top(1)

The cp_old array is allocated with malloc(3) and its pointer is passed to
percentages64().

In this function there happens a calculation of total_change, which value
depends on the value inside the unitialized cp_old[] array.

==26662==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x268a2c in percentages64 /usr/src/external/bsd/top/bin/../dist/machine/m_netbsd.c:1341:6
#1 0x26748b in get_system_info /usr/src/external/bsd/top/bin/../dist/machine/m_netbsd.c:478:6
#2 0x25518e in do_display /usr/src/external/bsd/top/bin/../dist/top.c:507:5
#3 0x253038 in main /usr/src/external/bsd/top/bin/../dist/top.c:975:2
#4 0x21cad1 in ___start (/usr/bin/top+0x1cad1)
SUMMARY: MemorySanitizer: use-of-uninitialized-value /usr/src/external/bsd/top/bin/../dist/machine/m_netbsd.c:1341:6 in percentages64
Exiting

Fix this issue by changling malloc(3) with calloc(3).

Detected with Memory Sanitizer during the integration of sanitizers with
the NetBSD basesystem.

Reported by <Yang Zheng>

diffstat:

 external/bsd/top/dist/machine/m_netbsd.c |  8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diffs (33 lines):

diff -r fb787631ef5b -r 791fea895649 external/bsd/top/dist/machine/m_netbsd.c
--- a/external/bsd/top/dist/machine/m_netbsd.c  Thu May 31 09:37:16 2018 +0000
+++ b/external/bsd/top/dist/machine/m_netbsd.c  Thu May 31 10:14:21 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: m_netbsd.c,v 1.19 2016/12/26 12:46:31 leot Exp $       */
+/*     $NetBSD: m_netbsd.c,v 1.20 2018/05/31 10:14:21 kamil Exp $      */
 
 /*
  * top - a top users display for Unix
@@ -37,12 +37,12 @@
  *             Andrew Doran <ad%NetBSD.org@localhost>
  *
  *
- * $Id: m_netbsd.c,v 1.19 2016/12/26 12:46:31 leot Exp $
+ * $Id: m_netbsd.c,v 1.20 2018/05/31 10:14:21 kamil Exp $
  */
 #include <sys/cdefs.h>
 
 #ifndef lint
-__RCSID("$NetBSD: m_netbsd.c,v 1.19 2016/12/26 12:46:31 leot Exp $");
+__RCSID("$NetBSD: m_netbsd.c,v 1.20 2018/05/31 10:14:21 kamil Exp $");
 #endif
 
 #include <sys/param.h>
@@ -335,7 +335,7 @@
                ncpu = 1;
 
        cpu_states = malloc(sizeof(cpu_states[0]) * CPUSTATES * ncpu);
-       cp_old = malloc(sizeof(cp_old[0]) * CPUSTATES * ncpu);
+       cp_old = calloc(CPUSTATES * ncpu, sizeof(cp_old[0]));
        cp_diff = malloc(sizeof(cp_diff[0]) * CPUSTATES * ncpu);
        if (cpu_states == NULL || cp_time == NULL || cp_old == NULL ||
            cp_diff == NULL) {