Re: Cursor support buffer patch - Mailing list pgsql-patches

From Bruce Momjian
Subject Re: Cursor support buffer patch
Date
Msg-id 200106110418.f5B4Ili10548@candle.pha.pa.us
Whole thread Raw
In response to Cursor support buffer patch  (Ian Lance Taylor <ian@airs.com>)
List pgsql-patches
Your patch has been added to the PostgreSQL unapplied patches list at:

    http://candle.pha.pa.us/cgi-bin/pgpatches

I will try to apply it within the next 48 hours.

> Here is a small patch for the cursor support which Jan recently added.
> The code assumed that there would be a '\0' in buf after storing the
> characters in new->refname, but it did nothing to ensure that.
>
> I can't convince myself that this code does not have the possibility
> of buffer overflow.  However, I have not tried to fix that.  For that
> matter, I see other possibilities for buffer overflow in gram.y, such
> as in decl_cursor_arglist.  Buffer overflow of this sort is not good,
> as it means that anybody who is permitted to create functions can
> completely break security.
>
> Ian
>
> Index: gram.y
> ===================================================================
> RCS file: /home/projects/pgsql/cvsroot/pgsql/src/pl/plpgsql/src/gram.y,v
> retrieving revision 1.20
> diff -u -p -r1.20 gram.y
> --- gram.y    2001/05/31 17:15:40    1.20
> +++ gram.y    2001/06/06 06:35:46
> @@ -385,7 +385,8 @@ decl_statement    : decl_varname decl_const
>                                  *cp2++ = '\\';
>                              *cp2++ = *cp1++;
>                          }
> -                        strcat(buf, "'");
> +                        *cp2++ = '\'';
> +                        *cp2 = '\0';
>                          curname_def->query = strdup(buf);
>                          new->default_val = curname_def;
>
>
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--
  Bruce Momjian                        |  http://candle.pha.pa.us
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