Bug in ResolveOneParam()

From: Rainer Bauer <usenet(at)munnin(dot)com>
To: pgsql-odbc(at)postgresql(dot)org
Subject: Bug in ResolveOneParam()
Date: 2007-07-16 10:09:59
Message-ID: j7fm935tfveflo3ubh8n02qk7ao172kd7j@4ax.com
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Hello,

I finally was able to track down the bug that occasionally happened when
UseServerSidePrepare was enabled: the driver is writing past allocated memory.

The bug is in ResolveOneParam(). At one point this function writes directly
into the allocated buffer <qb->query_statement> _without_ checking the
allocated size by calling enlarge_query_statement().

I have added the ENLARGE_NEWSTATEMENT() call which should take care of this
bug (see attached patch).

Rainer

Index: convert.c
===================================================================
RCS file: /cvsroot/psqlodbc/psqlodbc/convert.c,v
retrieving revision 1.161
diff -u -r1.161 convert.c
--- convert.c 4 Jun 2007 10:24:49 -0000 1.161
+++ convert.c 16 Jul 2007 09:52:51 -0000
@@ -3459,6 +3472,7 @@
} */
if (req_bind)
{
+ ENLARGE_NEWSTATEMENT( qb, (qb->npos+4) );
npos = qb->npos;
qb->npos += 4;
}

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