Bug#430108: cdebconf: Off by one error

[Baruch Even <baruch@debian.org>]

Package: cdebconf
Version: 0.116
Severity: normal
Tags: patch

A read could fill the whole buffer and we put a null-char at the end
of the read data so we could write on a byte just after our buffer. 

-- System Information:
Debian Release: lenny/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: i386 (i686)

Kernel: Linux 2.6.22-rc4-mexhat (SMP w/2 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages cdebconf depends on:
ii  libatk1.0-0                   1.18.0-2   The ATK accessibility toolkit
ii  libc6                         2.5-11     GNU C Library: Shared libraries
ii  libcairo2                     1.4.8-1    The Cairo 2D vector graphics libra
ii  libdebian-installer4          0.51       Library of common debian-installer
ii  libdirectfb-0.9-25            0.9.25.1-6 direct frame buffer graphics - sha
ii  libglib2.0-0                  2.12.12-1  The GLib library of C routines
ii  libgtk-directfb-2.0-0         2.10.13-1  The GTK+ graphical user interface 
ii  libgtk2.0-0                   2.10.13-1  The GTK+ graphical user interface 
ii  libnewt0.52                   0.52.2-10  Not Erik's Windowing Toolkit - tex
ii  libpango1.0-0                 1.16.4-1   Layout and rendering of internatio
ii  libtextwrap1                  0.1-5      text-wrapping library with i18n - 

cdebconf recommends no packages.

Index: confmodule.c
===================================================================
--- confmodule.c	(revision 47280)
+++ confmodule.c	(working copy)
@@ -84,7 +84,7 @@
                 return DC_OK;
             }
 
-            ret = read(mod->infd, buf, sizeof(buf));
+            ret = read(mod->infd, buf, sizeof(buf)-1);
             if (ret < 0) {
                 if (errno == EINTR)
                     continue;