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:
----
REL7_3_STABLE

Modified Files:
--------------
pgsql/doc/src/sgml/ref:
set_session_auth.sgml (r1.7 -> r1.7.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/set_session_auth.sgml?r1=1.7&r2=1.7.2.1)
pgsql/src/backend/access/transam:
xact.c (r1.135.2.4 -> r1.135.2.5)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xact.c?r1=1.135.2.4&r2=1.135.2.5)
pgsql/src/backend/catalog:
index.c (r1.202.2.1 -> r1.202.2.2)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/index.c?r1=1.202.2.1&r2=1.202.2.2)
pgsql/src/backend/commands:
schemacmds.c (r1.6 -> r1.6.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/schemacmds.c?r1=1.6&r2=1.6.2.1)
vacuum.c (r1.244.2.2 -> r1.244.2.3)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/vacuum.c?r1=1.244.2.2&r2=1.244.2.3)
variable.c (r1.71.2.4 -> r1.71.2.5)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/variable.c?r1=1.71.2.4&r2=1.71.2.5)
pgsql/src/backend/utils/adt:
ri_triggers.c (r1.43.2.5 -> r1.43.2.6)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/ri_triggers.c?r1=1.43.2.5&r2=1.43.2.6)
pgsql/src/backend/utils/fmgr:
fmgr.c (r1.63 -> r1.63.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/fmgr/fmgr.c?r1=1.63&r2=1.63.2.1)
pgsql/src/backend/utils/init:
miscinit.c (r1.96 -> r1.96.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/init/miscinit.c?r1=1.96&r2=1.96.2.1)
pgsql/src/include:
miscadmin.h (r1.111 -> r1.111.2.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/miscadmin.h?r1=1.111&r2=1.111.2.1)