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While the preceding commit prevented such attachments from occurring in future, this one aims to prevent further abuse of any already- created operator that exposes _int_matchsel to the wrong data types. (No other contrib module has a vulnerable selectivity estimator.) We need only check that the Const we've found in the query is indeed of the type we expect (query_int), but there's a difficulty: as an extension type, query_int doesn't have a fixed OID that we could hard-code into the estimator. Therefore, the bulk of this patch consists of infrastructure to let an extension function securely look up the OID of a datatype belonging to the same extension. (Extension authors have requested such functionality before, so we anticipate that this code will have additional non-security uses, and may soon be extended to allow looking up other kinds of SQL objects.) This is done by first finding the extension that owns the calling function (there can be only one), and then thumbing through the objects owned by that extension to find a type that has the desired name. This is relatively expensive, especially for large extensions, so a simple cache is put in front of these lookups. Reported-by: Daniel Firer as part of zeroday.cloud Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Noah Misch <noah@leadboat.com> Security: CVE-2026-2004 Backpatch-through: 14
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.