[src/trunk]: src/bin/ps Fix an unitialized memory read bug in ps(1)

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

details:   https://anonhg.NetBSD.org/src/rev/7a3a28e66dab
branches:  trunk
changeset: 828967:7a3a28e66dab
user:      kamil <kamil%NetBSD.org@localhost>
date:      Fri Jan 12 23:01:14 2018 +0000

description:
Fix an unitialized memory read bug in ps(1)

rawcpu of type int, is declared inside main(){} and it can be passed as
uninitialized to setpinfo().
The setpinfo() function has a switch checking the value of rawcpu:

  if (!rawcpu)
    pi[i].pcpu /= 1.0 - exp(ki[i].p_swtime * log_ccpu);

rawcpu is set to 1 with the command line argument "-C".

   -C           Change the way the CPU percentage is calculated by using a
                "raw" CPU calculation that ignores "resident" time (this
                normally has no effect).

Bug reproducible with an invocation: "ps u". It hides with "ps uC".

Initialize rawcpu by default to 0, before the getopt(3) machinery.

Detected with MSan running on NetBSD/amd64.

Sponsored by <The NetBSD Foundation>

diffstat:

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

diffs (27 lines):

diff -r 44ef65427265 -r 7a3a28e66dab bin/ps/ps.c
--- a/bin/ps/ps.c       Fri Jan 12 19:38:52 2018 +0000
+++ b/bin/ps/ps.c       Fri Jan 12 23:01:14 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ps.c,v 1.88 2016/12/26 20:52:39 rin Exp $      */
+/*     $NetBSD: ps.c,v 1.89 2018/01/12 23:01:14 kamil Exp $    */
 
 /*
  * Copyright (c) 2000-2008 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
 #if 0
 static char sccsid[] = "@(#)ps.c       8.4 (Berkeley) 4/2/94";
 #else
-__RCSID("$NetBSD: ps.c,v 1.88 2016/12/26 20:52:39 rin Exp $");
+__RCSID("$NetBSD: ps.c,v 1.89 2018/01/12 23:01:14 kamil Exp $");
 #endif
 #endif /* not lint */
 
@@ -224,7 +224,7 @@
        if (argc > 1)
                argv[1] = kludge_oldps_options(argv[1]);
 
-       descendancy = fmt = prtheader = wflag = xflg = showlwps = 0;
+       descendancy = fmt = prtheader = wflag = xflg = rawcpu = showlwps = 0;
        what = KERN_PROC_UID;
        flag = myuid = getuid();
        memf = nlistf = swapf = NULL;