From 0c0fd9a15ecff4eebb0e9e6e1a6ce2a6550e397a Mon Sep 17 00:00:00 2001
From: Przemyslaw Czerpak <druzus@priv.onet.pl>
Date: Wed, 5 May 2010 07:58:32 +0000
Subject: [PATCH] 2010-05-05 09:58 UTC+0200 Przemyslaw Czerpak
 (druzus/at/priv.onet.pl)   * harbour/src/compiler/gencc.c     ! fixed
 possible HVM stack corruption by dummy (alias->field) code       which does
 not store the result. The problem was exploited by       code generated for
 -gc3 mode only. Here is self contain example:             proc main()        
     begin sequence with {||break()}                p()             end
 sequence             proc p()                (test->name)               
 (test->name)             return

---
 harbour/ChangeLog            | 14 ++++++++++++++
 harbour/src/compiler/gencc.c | 16 ++++++++--------
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index 376e821000..cdeebe3c65 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -17,6 +17,20 @@
    past entries belonging to author(s): Viktor Szakats.
 */
 
+2010-05-05 09:58 UTC+0200 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
+  * harbour/src/compiler/gencc.c
+    ! fixed possible HVM stack corruption by dummy (alias->field) code
+      which does not store the result. The problem was exploited by
+      code generated for -gc3 mode only. Here is self contain example:
+            proc main()
+            begin sequence with {||break()}
+               p()
+            end sequence
+            proc p()
+               (test->name)
+               (test->name)
+            return
+
 2010-05-05 08:02 UTC+0200 Viktor Szakats (harbour.01 syenar.hu)
   * src/rtl/achoice.prg
     ! Added patch by Jerry Finuliar to fine tune cursor
diff --git a/harbour/src/compiler/gencc.c b/harbour/src/compiler/gencc.c
index ac20f1cddf..3f68ea2204 100644
--- a/harbour/src/compiler/gencc.c
+++ b/harbour/src/compiler/gencc.c
@@ -1411,25 +1411,25 @@ static HB_GENC_FUNC( hb_p_pushsym )
             return 4;
          case HB_P_PUSHALIASEDFIELDNEAR:
             fprintf( cargo->yyc,
-                     "\thb_xvmPushAliasedFieldExt( symbols + %u, symbols + %u );\n",
+                     "\tif( hb_xvmPushAliasedFieldExt( symbols + %u, symbols + %u ) ) break;\n",
                      HB_PCODE_MKUSHORT( &pFunc->pCode[ lPCodePos + 1 ] ),
                      pFunc->pCode[ lPCodePos + 4 ] );
             return 5;
          case HB_P_PUSHALIASEDFIELD:
             fprintf( cargo->yyc,
-                     "\thb_xvmPushAliasedFieldExt( symbols + %u, symbols + %u );\n",
+                     "\tif( hb_xvmPushAliasedFieldExt( symbols + %u, symbols + %u ) ) break;\n",
                      HB_PCODE_MKUSHORT( &pFunc->pCode[ lPCodePos + 1 ] ),
                      HB_PCODE_MKUSHORT( &pFunc->pCode[ lPCodePos + 4 ] ) );
             return 6;
          case HB_P_POPALIASEDFIELDNEAR:
             fprintf( cargo->yyc,
-                     "\thb_xvmPopAliasedFieldExt( symbols + %u, symbols + %u );\n",
+                     "\tif( hb_xvmPopAliasedFieldExt( symbols + %u, symbols + %u ) ) break;\n",
                      HB_PCODE_MKUSHORT( &pFunc->pCode[ lPCodePos + 1 ] ),
                      pFunc->pCode[ lPCodePos + 4 ] );
             return 5;
          case HB_P_POPALIASEDFIELD:
             fprintf( cargo->yyc,
-                     "\thb_xvmPopAliasedFieldExt( symbols + %u, symbols + %u );\n",
+                     "\tif( hb_xvmPopAliasedFieldExt( symbols + %u, symbols + %u ) ) break;\n",
                      HB_PCODE_MKUSHORT( &pFunc->pCode[ lPCodePos + 1 ] ),
                      HB_PCODE_MKUSHORT( &pFunc->pCode[ lPCodePos + 4 ] ) );
             return 6;
@@ -1455,25 +1455,25 @@ static HB_GENC_FUNC( hb_p_pushsymnear )
             return 3;
          case HB_P_PUSHALIASEDFIELDNEAR:
             fprintf( cargo->yyc,
-                     "\thb_xvmPushAliasedFieldExt( symbols + %u, symbols + %u );\n",
+                     "\tif( hb_xvmPushAliasedFieldExt( symbols + %u, symbols + %u ) ) break;\n",
                      pFunc->pCode[ lPCodePos + 1 ],
                      pFunc->pCode[ lPCodePos + 3 ] );
             return 4;
          case HB_P_PUSHALIASEDFIELD:
             fprintf( cargo->yyc,
-                     "\thb_xvmPushAliasedFieldExt( symbols + %u, symbols + %u );\n",
+                     "\tif( hb_xvmPushAliasedFieldExt( symbols + %u, symbols + %u ) ) break;\n",
                      pFunc->pCode[ lPCodePos + 1 ],
                      HB_PCODE_MKUSHORT( &pFunc->pCode[ lPCodePos + 3 ] ) );
             return 5;
          case HB_P_POPALIASEDFIELDNEAR:
             fprintf( cargo->yyc,
-                     "\thb_xvmPopAliasedFieldExt( symbols + %u, symbols + %u );\n",
+                     "\tif( hb_xvmPopAliasedFieldExt( symbols + %u, symbols + %u ) ) break;\n",
                      pFunc->pCode[ lPCodePos + 1 ],
                      pFunc->pCode[ lPCodePos + 3 ] );
             return 4;
          case HB_P_POPALIASEDFIELD:
             fprintf( cargo->yyc,
-                     "\thb_xvmPopAliasedFieldExt( symbols + %u, symbols + %u );\n",
+                     "\tif( hb_xvmPopAliasedFieldExt( symbols + %u, symbols + %u ) ) break;\n",
                      pFunc->pCode[ lPCodePos + 1 ],
                      HB_PCODE_MKUSHORT( &pFunc->pCode[ lPCodePos + 3 ] ) );
             return 5;