From ce9dabb83ff590c1c0814b10d18a3acf218d3ba5 Mon Sep 17 00:00:00 2001
From: Stas Degteff <stas_degteff@users.sourceforge.net>
Date: Tue, 22 Feb 2011 20:25:14 +0000
Subject: [PATCH] Fix buffer overfow with zeroing stack

---
 golded3/geutil.cpp | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/golded3/geutil.cpp b/golded3/geutil.cpp
index 896afd8..4f3f2b8 100644
--- a/golded3/geutil.cpp
+++ b/golded3/geutil.cpp
@@ -38,13 +38,14 @@ extern GPickArealist* PickArealist;
 //  ------------------------------------------------------------------
 
 void update_statuslines() {
-
-  char buf[200];    /* FIXME: it is need to use dynamic arrays in this fuction to prevent buffer overflow or screen garbage */
-  char * const buf_end = buf+199;
-  static char old_status_line[200] = "";
-  char * const old_status_line_end = old_status_line+199;
+# define BUFSIZE 200
+# define BUFLEN  199
+  char buf[BUFSIZE]="";    /* FIXME: it is need to use dynamic arrays in this fuction to prevent buffer overflow or screen garbage */
+  char * const buf_end = buf+BUFLEN;
+  static char old_status_line[BUFSIZE] = "";
+  char * const old_status_line_end = old_status_line+BUFLEN;
   static int called = NO;
-  const int WIDE= sizeof(buf)>MAXCOL? MAXCOL : sizeof(buf)-1;
+  const int WIDE= BUFLEN>MAXCOL? MAXCOL : BUFLEN;
 
   HandleGEvent(EVTT_REMOVEVOCBUF);
 
@@ -54,7 +55,7 @@ void update_statuslines() {
     called = YES;
 
     vchar sep = _box_table(W_BSTAT, 3);
-    char help[200], clkinfo[200];
+    char help[BUFSIZE], clkinfo[BUFSIZE];
     *clkinfo = NUL;
     *help = NUL;
 
@@ -86,15 +87,12 @@ void update_statuslines() {
     int help_len = strlen(help);
     int clk_len = strlen(clkinfo);
     int len = WIDE-help_len-clk_len-2;
-//    LOG.printf("! --- %i bytes help=\"%s\"", help_len, help?help:"NULL");
-//    LOG.printf("! --- %i bytes information=\"%s\"", len, information?information:"NULL");
-//    LOG.printf("! --- %i bytes clkinfo=\"%s\"", clk_len, clkinfo?clkinfo:"NULL");
     gsprintf(PRINTF_DECLARE_BUFFER(buf), "%c%s%-*.*s%s ", goldmark, help, len, len, information, clkinfo);
 
     char *begin = buf;
     char *obegin = old_status_line;
-    char *end = buf + WIDE;
-    char *oend = old_status_line + WIDE;
+    char *end = buf + WIDE-1;               // last position before final '\0'
+    char *oend = old_status_line + WIDE-1;  // last position before final '\0'
     while((*begin != NUL) and (*begin == *obegin) and (begin<buf_end) and (obegin<old_status_line_end)) {
       ++begin;
       ++obegin;
@@ -130,6 +128,8 @@ void update_statuslines() {
       gmou.ShowCursor();
     #endif
   }
+# undef BUFSIZE
+# undef BUFLEN
 } /* update_statuslines() */