Re: pgsql: Fix failure due to accessing an - Mailing list pgsql-committers

Tom,

Is this a fix for security hole/vulnerability?
One of our engineer claimed that double free bug itself is a
vulnerability, thus 8.2.1 release should be called as "security
release".
--
Tatsuo Ishii
SRA OSS, Inc. Japan

> Log Message:
> -----------
> Fix failure due to accessing an already-freed tuple descriptor in a plan
> involving HashAggregate over SubqueryScan (this is the known case, there
> may well be more).  The bug is only latent in releases before 8.2 since they
> didn't try to access tupletable slots' descriptors during ExecDropTupleTable.
> The least bogus fix seems to be to make subqueries share the parent query's
> memory context, so that tupdescs they create will have the same lifespan as
> those of the parent query.  There are comments in the code envisioning going
> even further by not having a separate child EState at all, but that will
> require rethinking executor access to range tables, which I don't want to
> tackle right now.  Per bug report from Jean-Pierre Pelletier.
>
> Tags:
> ----
> REL8_2_STABLE
>
> Modified Files:
> --------------
>     pgsql/src/backend/executor:
>         execMain.c (r1.280 -> r1.280.2.1)
>         (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execMain.c.diff?r1=1.280&r2=1.280.2.1)
>         execUtils.c (r1.140 -> r1.140.2.1)
>
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execUtils.c.diff?r1=1.140&r2=1.140.2.1)
>         nodeSubplan.c (r1.80 -> r1.80.2.1)
>
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/nodeSubplan.c.diff?r1=1.80&r2=1.80.2.1)
>         nodeSubqueryscan.c (r1.32.2.1 -> r1.32.2.2)
>
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/nodeSubqueryscan.c.diff?r1=1.32.2.1&r2=1.32.2.2)
>     pgsql/src/include/executor:
>         executor.h (r1.130 -> r1.130.2.1)
>         (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/executor/executor.h.diff?r1=1.130&r2=1.130.2.1)
>     pgsql/src/include/nodes:
>         execnodes.h (r1.161 -> r1.161.2.1)
>         (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/execnodes.h.diff?r1=1.161&r2=1.161.2.1)
>
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