pgsql: Make standard maintenance operations (including VACUUM, ANALYZE,

Log Message:
-----------
Make standard maintenance operations (including VACUUM, ANALYZE, REINDEX,
and CLUSTER) execute as the table owner rather than the calling user, using
the same privilege-switching mechanism already used for SECURITY DEFINER
functions. The purpose of this change is to ensure that user-defined
functions used in index definitions cannot acquire the privileges of a
superuser account that is performing routine maintenance. While a function
used in an index is supposed to be IMMUTABLE and thus not able to do anything
very interesting, there are several easy ways around that restriction; and
even if we could plug them all, there would remain a risk of reading sensitive
information and broadcasting it through a covert channel such as CPU usage.

To prevent bypassing this security measure, execution of SET SESSION
AUTHORIZATION and SET ROLE is now forbidden within a SECURITY DEFINER context.

Thanks to Itagaki Takahiro for reporting this vulnerability.

Security: CVE-2007-6600

Tags:
----
REL8_0_STABLE

Modified Files:
--------------
pgsql/doc/src/sgml/ref:
set_session_auth.sgml (r1.12 -> r1.12.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/set_session_auth.sgml?r1=1.12&r2=1.12.4.1)
pgsql/src/backend/access/transam:
xact.c (r1.195.4.3 -> r1.195.4.4)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xact.c?r1=1.195.4.3&r2=1.195.4.4)
pgsql/src/backend/catalog:
index.c (r1.244.4.2 -> r1.244.4.3)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/index.c?r1=1.244.4.2&r2=1.244.4.3)
pgsql/src/backend/commands:
analyze.c (r1.80 -> r1.80.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/analyze.c?r1=1.80&r2=1.80.4.1)
schemacmds.c (r1.27 -> r1.27.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/schemacmds.c?r1=1.27&r2=1.27.4.1)
vacuum.c (r1.299.4.2 -> r1.299.4.3)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/vacuum.c?r1=1.299.4.2&r2=1.299.4.3)
variable.c (r1.105.4.3 -> r1.105.4.4)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/variable.c?r1=1.105.4.3&r2=1.105.4.4)
pgsql/src/backend/utils/adt:
ri_triggers.c (r1.76.4.2 -> r1.76.4.3)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/ri_triggers.c?r1=1.76.4.2&r2=1.76.4.3)
pgsql/src/backend/utils/fmgr:
fmgr.c (r1.88.4.2 -> r1.88.4.3)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/fmgr/fmgr.c?r1=1.88.4.2&r2=1.88.4.3)
pgsql/src/backend/utils/init:
miscinit.c (r1.137.4.1 -> r1.137.4.2)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/init/miscinit.c?r1=1.137.4.1&r2=1.137.4.2)
pgsql/src/include:
miscadmin.h (r1.174 -> r1.174.4.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/miscadmin.h?r1=1.174&r2=1.174.4.1)