From: Tom Lane Date: Tue, 29 Nov 2022 16:46:33 +0000 (-0500) Subject: Prevent clobbering of utility statements in SQL function caches. X-Git-Tag: REL_16_BETA1~1212 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8b47ccb624f8bffc1789fe11769a706c2050f171;p=thirdparty%2Fpostgresql.git Prevent clobbering of utility statements in SQL function caches. This is an oversight in commit 7c337b6b5: I apparently didn't think about the possibility of a SQL function being executed multiple times within a query. In that case, functions.c's primitive caching mechanism allows the same utility parse tree to be presented for execution more than once. We have to tell ProcessUtility to make a working copy of the parse tree, or bad things happen. Normally I'd add a regression test, but I think the reported crasher is dependent on some rather random implementation choices that are nowhere near functions.c, so its usefulness as a long-lived test feels questionable. In any case, this fix is clearly correct given the design choices of 7c337b6b5. Per bug #17702 from Xin Wen. Thanks to Daniel Gustafsson for analysis. Back-patch to v14 where the faulty commit came in (before that, the responsibility for copying scribble-able utility parse trees lay elsewhere). Discussion: https://postgr.es/m/17702-ad24fdcdd1e9047a@postgresql.org --- diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c index e134a82ff7e..dc136251719 100644 --- a/src/backend/executor/functions.c +++ b/src/backend/executor/functions.c @@ -884,7 +884,7 @@ postquel_getnext(execution_state *es, SQLFunctionCachePtr fcache) { ProcessUtility(es->qd->plannedstmt, fcache->src, - false, + true, /* protect function cache's parsetree */ PROCESS_UTILITY_QUERY, es->qd->params, es->qd->queryEnv,