postgresql/contrib
Michael Paquier ab40b0395a intarray: Prevent out-of-bound memory reads with gist__int_ops
As gist__int_ops stands in intarray, it is possible to store GiST
entries for leaf pages that can cause corruptions when decompressed.
Leaf nodes are stored as decompressed all the time by the compression
method, and the decompression method should map with that, retrieving
the contents of the page without doing any decompression.  However, the
code authorized the insertion of leaf page data with a higher number of
array items than what can be supported, generating a NOTICE message to
inform about this matter (199 for a 8k page, for reference).  When
calling the decompression method, a decompression would be attempted on
this leaf node item but the contents should be retrieved as they are.

The NOTICE message generated when dealing with the compression of a leaf
page and too many elements in the input array for gist__int_ops has been
introduced by 08ee64e, removing the marker stored in the array to track
if this is actually a leaf node.  However, it also missed the fact that
the decompression path should do nothing for a leaf page.  Hence, as the
code stand, a too-large array would be stored as uncompressed but the
decompression path would attempt a decompression rather that retrieving
the contents as they are.

This leads to various problems.  First, even if 08ee64e tried to address
that, it is possible to do out-of-bound chunk writes with a large input
array, with the backend informing about that with WARNINGs.  On
decompression, retrieving the stored leaf data would lead to incorrect
memory reads, leading to crashes or even worse.

Perhaps somebody would be interested in expanding the number of array
items that can be handled in a leaf page for this operator in the
future, which would require revisiting the choice done in 08ee64e, but
based on the lack of reports about this problem since 2005 it does not
look so.  For now, this commit prevents the insertion of data for leaf
pages when using more array items that the code can handle on
decompression, switching the NOTICE message to an ERROR.  If one wishes
to use more array items, gist__intbig_ops is an optional choice.

While on it, use ERRCODE_PROGRAM_LIMIT_EXCEEDED as error code when a
limit is reached, because that's what the module is facing in such
cases.

Author: Ankit Kumar Pandey, Alexander Lakhin
Reviewed-by: Richard Guo, Michael Paquier
Discussion: https://postgr.es/m/796b65c3-57b7-bddf-b0d5-a8afafb8b627@gmail.com
Discussion: https://postgr.es/m/17888-f72930e6b5ce8c14@postgresql.org
Backpatch-through: 11
2023-06-15 13:45:44 +09:00
..
adminpack Read until EOF vice stat-reported size in read_binary_file 2020-07-04 06:29:03 -04:00
amcheck Replace RelationOpenSmgr() with RelationGetSmgr(). 2022-11-17 16:54:31 -05:00
auth_delay Update copyright for 2018 2018-01-02 23:30:12 -05:00
auto_explain Fix ancient memory leak in contrib/auto_explain. 2021-02-02 13:49:08 -05:00
bloom Replace RelationOpenSmgr() with RelationGetSmgr(). 2022-11-17 16:54:31 -05:00
btree_gin Fix failure of btree_gin indexscans with "char" type and </<= operators. 2021-08-10 18:10:30 -04:00
btree_gist Fix results of index-only scans on btree_gist char(N) indexes. 2022-01-08 14:54:39 -05:00
citext CREATE INDEX: use the original userid for more ACL checks. 2022-06-25 09:07:46 -07:00
cube Make contrib modules' installation scripts more secure. 2020-08-10 10:44:43 -04:00
dblink postgres_fdw: Fix unexpected reporting of empty message. 2021-12-03 17:37:26 +09:00
dict_int Ensure maxlen is at leat 1 in dict_int 2019-12-03 18:41:29 +01:00
dict_xsyn Avoid unnecessary use of pg_strcasecmp for already-downcased identifiers. 2018-01-26 18:25:14 -05:00
earthdistance Make contrib modules' installation scripts more secure. 2020-08-10 10:44:43 -04:00
file_fdw Ensure that foreign scans with lateral refs are planned correctly. 2019-02-07 13:11:13 -05:00
fuzzystrmatch Ensure Soundex difference() function handles empty input sanely. 2023-05-16 10:53:42 -04:00
hstore hstore: Tighten key/value parsing check for whitespaces 2023-06-12 09:14:20 +09:00
hstore_plperl Still further rethinking of build changes for macOS Mojave. 2018-10-18 14:55:23 -04:00
hstore_plpython In hstore_plpython, avoid crashing when return value isn't a mapping. 2023-04-27 11:55:06 -04:00
intagg Make contrib modules' installation scripts more secure. 2020-08-10 10:44:43 -04:00
intarray intarray: Prevent out-of-bound memory reads with gist__int_ops 2023-06-15 13:45:44 +09:00
isn Provide for contrib and pgxs modules to install include files. 2018-07-31 19:58:39 +01:00
jsonb_plperl Fix handling of "undef" in contrib/jsonb_plperl. 2019-08-04 14:05:35 -04:00
jsonb_plpython In jsonb_plpython.c, suppress warning message from gcc 10. 2020-01-30 18:26:15 -05:00
lo Fix bogus CALLED_AS_TRIGGER() defenses. 2020-04-03 11:24:56 -04:00
ltree Make contrib modules' installation scripts more secure. 2020-08-10 10:44:43 -04:00
ltree_plpython Fix out-of-tree build for transform modules. 2018-09-16 19:13:59 +01:00
oid2name Report the true database name on connection errors 2021-01-26 16:42:13 -03:00
pageinspect pageinspect: Fix handling of all-zero pages 2022-04-14 15:09:42 +09:00
passwordcheck Fix handling of previous password hooks in passwordcheck 2019-08-01 09:38:02 +09:00
pg_buffercache Phase 2 of pgindent updates. 2017-06-21 15:19:25 -04:00
pg_freespacemap Default monitoring roles 2017-03-30 14:18:53 -04:00
pg_prewarm Replace RelationOpenSmgr() with RelationGetSmgr(). 2022-11-17 16:54:31 -05:00
pg_standby Avoid using potentially-under-aligned page buffers. 2018-09-01 15:27:13 -04:00
pg_stat_statements pg_stat_statements: fetch stmt location/length before it disappears. 2022-11-01 12:48:01 -04:00
pg_trgm Fix misbehavior in contrib/pg_trgm with an unsatisfiable regex. 2023-03-11 12:15:41 -05:00
pg_visibility Replace RelationOpenSmgr() with RelationGetSmgr(). 2022-11-17 16:54:31 -05:00
pgcrypto Clean up assorted failures under clang's -fsanitize=undefined checks. 2022-03-03 18:13:24 -05:00
pgrowlocks Avoid holding a directory FD open across assorted SRF calls. 2020-03-16 21:05:54 -04:00
pgstattuple pgstatindex, pageinspect: handle partitioned indexes 2018-05-09 14:22:59 -03:00
postgres_fdw postgres_fdw: Avoid 'variable not found in subplan target list' error. 2022-09-14 18:45:07 +09:00
seg Fix contrib/seg to be more wary of long input numbers. 2022-12-21 17:51:50 -05:00
sepgsql Adjust sepgsql expected output for 681d9e462 et al. 2023-05-08 11:24:47 -04:00
spi Prevent accidental linking of system-supplied copies of libpq.so etc. 2018-04-03 16:26:05 -04:00
sslinfo Phase 3 of pgindent updates. 2017-06-21 15:35:54 -04:00
start-scripts Remove contrib/start-scripts/osx/. 2017-11-17 12:53:20 -05:00
tablefunc Disallow null category in crosstab_hash 2019-12-23 13:33:42 -05:00
tcn Post-feature-freeze pgindent run. 2018-04-26 14:47:16 -04:00
test_decoding Fix assertion failures while processing NEW_CID record in logical decoding. 2022-10-20 09:07:04 +05:30
tsm_system_rows Update copyright for 2018 2018-01-02 23:30:12 -05:00
tsm_system_time Update copyright for 2018 2018-01-02 23:30:12 -05:00
unaccent Make contrib/unaccent's unaccent() function work when not in search path. 2018-09-06 10:49:45 -04:00
uuid-ossp Reject bogus output from uuid_create(3). 2022-09-09 12:41:36 -04:00
vacuumlo Report the true database name on connection errors 2021-01-26 16:42:13 -03:00
xml2 Phase 3 of pgindent updates. 2017-06-21 15:35:54 -04:00
Makefile Transforms for jsonb to PL/Perl 2018-04-03 09:47:18 -04:00
README Rename 'gmake' to 'make' in docs and recommended commands 2014-02-12 17:29:19 -05:00
contrib-global.mk Respect TEMP_CONFIG when pg_regress_check and friends are called 2016-02-27 12:28:21 -05:00

README

The PostgreSQL contrib tree
---------------------------

This subtree contains porting tools, analysis utilities, and plug-in
features that are not part of the core PostgreSQL system, mainly
because they address a limited audience or are too experimental to be
part of the main source tree.  This does not preclude their
usefulness.

User documentation for each module appears in the main SGML
documentation.

When building from the source distribution, these modules are not
built automatically, unless you build the "world" target.  You can
also build and install them all by running "make all" and "make
install" in this directory; or to build and install just one selected
module, do the same in that module's subdirectory.

Some directories supply new user-defined functions, operators, or
types.  To make use of one of these modules, after you have installed
the code you need to register the new SQL objects in the database
system by executing a CREATE EXTENSION command.  In a fresh database,
you can simply do

    CREATE EXTENSION module_name;

See the PostgreSQL documentation for more information about this
procedure.