Release date: 2005-05-09
This release contains a variety of fixes from 7.4.7, including several security-related issues. For information about new features in the 7.4 major release, see Section E.31.
A dump/restore is not required for those running 7.4.X. However, it is one possible way of handling two significant security problems that have been found in the initial contents of 7.4.X system catalogs. A dump/initdb/reload sequence using 7.4.8's initdb will automatically correct these problems.
The larger security problem is that the built-in character set encoding conversion functions can be invoked from SQL commands by unprivileged users, but the functions were not designed for such use and are not secure against malicious choices of arguments. The fix involves changing the declared parameter list of these functions so that they can no longer be invoked from SQL commands. (This does not affect their normal use by the encoding conversion machinery.)
The lesser problem is that the contrib/tsearch2 module creates several functions that are misdeclared to return internal when they do not accept internal arguments. This breaks type safety for all functions using internal arguments.
It is strongly recommended that all installations repair these errors, either by initdb or by following the manual repair procedures given below. The errors at least allow unprivileged database users to crash their server process, and might allow unprivileged users to gain the privileges of a database superuser.
If you wish not to do an initdb, perform the following procedures instead. As the database superuser, do:
BEGIN; UPDATE pg_proc SET proargtypes = 'internal'::regtype WHERE pronamespace = 11 AND pronargs = 5 AND proargtypes = 'cstring'::regtype; -- The command should report having updated 90 rows; -- if not, rollback and investigate instead of committing! COMMIT;
Next, if you have installed contrib/tsearch2, do:
BEGIN; UPDATE pg_proc SET proargtypes = 'internal'::regtype WHERE oid IN ( 'dex_init(text)'::regprocedure, 'snb_en_init(text)'::regprocedure, 'snb_ru_init(text)'::regprocedure, 'spell_init(text)'::regprocedure, 'syn_init(text)'::regprocedure ); -- The command should report having updated 5 rows; -- if not, rollback and investigate instead of committing! COMMIT;
If this command fails with a message like "function "dex_init(text)" does not exist", then either tsearch2 is not installed in this database, or you already did the update.
The above procedures must be carried out in each database of an installation, including template1, and ideally including template0 as well. If you do not fix the template databases then any subsequently created databases will contain the same errors. template1 can be fixed in the same way as any other database, but fixing template0 requires additional steps. First, from any database issue:
UPDATE pg_database SET datallowconn = true WHERE datname = 'template0';
Next connect to template0 and perform the above repair procedures. Finally, do:
-- re-freeze template0: VACUUM FREEZE; -- and protect it against future alterations: UPDATE pg_database SET datallowconn = false WHERE datname = 'template0';
Change encoding function signature to prevent misuse
Change contrib/tsearch2 to avoid unsafe use of INTERNAL function results
Repair ancient race condition that allowed a transaction to be seen as committed for some purposes (eg SELECT FOR UPDATE) slightly sooner than for other purposes
This is an extremely serious bug since it could lead to apparent data inconsistencies being briefly visible to applications.
Repair race condition between relation extension and VACUUM
This could theoretically have caused loss of a page's worth of freshly-inserted data, although the scenario seems of very low probability. There are no known cases of it having caused more than an Assert failure.
Fix comparisons of TIME WITH TIME ZONE values
The comparison code was wrong in the case where the --enable-integer-datetimes configuration switch had been used. NOTE: if you have an index on a TIME WITH TIME ZONE column, it will need to be REINDEXed after installing this update, because the fix corrects the sort order of column values.
TIME WITH TIME ZONE values
Fix mis-display of negative fractional seconds in INTERVAL values
This error only occurred when the --enable-integer-datetimes configuration switch had been used.
Ensure operations done during backend shutdown are counted by statistics collector
This is expected to resolve reports of pg_autovacuum not vacuuming the system catalogs often enough — it was not being told about catalog deletions caused by temporary table removal during backend exit.
Additional buffer overrun checks in plpgsql (Neil)
Fix pg_dump to dump trigger names containing % correctly (Neil)
Fix contrib/pgcrypto for newer OpenSSL builds (Marko Kreen)
Still more 64-bit fixes for contrib/intagg
Prevent incorrect optimization of functions returning RECORD
from dumping core for month-related formats
Prevent crash on COALESCE(NULL,NULL)
array_map to call PL
Fix permission checking in ALTER DATABASE RENAME
Fix ALTER LANGUAGE RENAME
clean up after itself
This fixes a lock management error that would only be visible if a transaction was kicked out of a wait for a lock (typically by query cancel) and then the holder of the lock released it within a very narrow window.
Fix problem with untyped parameter appearing in INSERT ... SELECT
Fix CLUSTER failure after ALTER TABLE SET WITHOUT OIDS