postgresql/src
Tom Lane 0fce76b99d Fix corner-case uninitialized-variable issues in plpgsql.
If an error was raised during our initial attempt to check whether
a successfully-compiled expression is "simple", subsequent calls of
exec_stmt_execsql would suppose that stmt->mod_stmt was already computed
when it had not been.  This could lead to assertion failures in debug
builds; in production builds the effect would typically be to act as
if INTO STRICT had been specified even when it had not been.  Of course
that only matters if the subsequent attempt to execute the expression
succeeds, so that the problem can only be reached by fixing a failure
in some referenced, inline-able SQL function and then retrying the
calling plpgsql function in the same session.

(There might be even-more-obscure ways to change the expression's
behavior without changing the plpgsql function, but that one seems
like the only one people would be likely to hit in practice.)

The most foolproof way to fix this would be to arrange for
exec_prepare_plan to not set expr->plan until we've finished the
subsidiary simple-expression check.  But it seems hard to do that
without creating reference-count leak issues.  So settle for documenting
the hazard in a comment and fixing exec_stmt_execsql to test separately
for whether it's computed stmt->mod_stmt.  (That adds a test-and-branch
per execution, but hopefully that's negligible in context.)  In v11 and
up, also fix exec_stmt_call which had a variant of the same issue.

Per bug #17113 from Alexander Lakhin.  Back-patch to all
supported branches.

Discussion: https://postgr.es/m/17113-077605ce00e0e7ec@postgresql.org
2021-07-20 13:01:48 -04:00
..
backend Don't allow to set replication slot_name as ''. 2021-07-19 11:04:21 +05:30
bin Fix some issues with WAL segment opening for pg_receivewal --compress 2021-07-20 12:12:51 +09:00
common Fix incautious handling of possibly-miscoded strings in client code. 2021-06-07 14:15:25 -04:00
fe_utils Fix incautious handling of possibly-miscoded strings in client code. 2021-06-07 14:15:25 -04:00
include Preserve firing-on state when cloning row triggers to partitions 2021-07-16 13:01:43 -04:00
interfaces Don't use abort(3) in libpq's fe-print.c. 2021-06-28 14:17:42 -04:00
makefiles Remove libpq.rc, use win32ver.rc for libpq 2020-01-15 15:06:12 +01:00
pl Fix corner-case uninitialized-variable issues in plpgsql. 2021-07-20 13:01:48 -04:00
port Add fallback implementation for setenv() 2021-06-01 09:27:25 +09:00
template Further tweaking of PG_SYSROOT heuristics for macOS. 2021-01-20 12:07:31 -05:00
test Make new replication slot test code even less racy 2021-07-19 17:21:07 -04:00
timezone Update time zone data files to tzdata release 2021a. 2021-01-24 16:29:47 -05:00
tools Ensure HAVE_DECL_XXX macros in MSVC builds match those in Unix. 2021-07-15 11:00:43 -04:00
tutorial tutorial: land height is "elevation", not "altitude" 2021-03-10 20:25:18 -05:00
.gitignore Convert cvsignore to gitignore, and add .gitignore for build targets. 2010-09-22 12:57:04 +02:00
DEVELOPERS Replace a couple of references to files that no longer exist in the source 2009-05-04 08:08:47 +00:00
Makefile Fix partial-build problems introduced by having more generated headers. 2018-04-09 16:42:10 -04:00
Makefile.global.in Fix prove_installcheck to use correct paths when used with PGXS 2021-07-01 08:46:38 -04:00
Makefile.shlib Add PostgreSQL home page to --help output 2020-02-28 13:12:21 +01:00
nls-global.mk NLS: Fix backend gettext triggers 2019-09-23 09:04:20 +02:00