From 552c310ba4ec072a2df48a08722f0af2e3703fdf Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 10 Dec 2018 11:12:43 -0500 Subject: [PATCH] Add stack depth checks to key recursive functions in backend/nodes/*.c. Although copyfuncs.c has a check_stack_depth call in its recursion, equalfuncs.c, outfuncs.c, and readfuncs.c lacked one. This seems unwise. Likewise fix planstate_tree_walker(), in branches where that exists. Discussion: https://postgr.es/m/30253.1544286631@sss.pgh.pa.us --- src/backend/nodes/equalfuncs.c | 4 ++++ src/backend/nodes/outfuncs.c | 4 ++++ src/backend/nodes/readfuncs.c | 4 ++++ 3 files changed, 12 insertions(+) diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c index 9a50523d47..e32b96eb1e 100644 --- a/src/backend/nodes/equalfuncs.c +++ b/src/backend/nodes/equalfuncs.c @@ -29,6 +29,7 @@ #include "postgres.h" +#include "miscadmin.h" #include "nodes/relation.h" #include "utils/datum.h" @@ -2676,6 +2677,9 @@ equal(const void *a, const void *b) if (nodeTag(a) != nodeTag(b)) return false; + /* Guard against stack overflow due to overly complex expressions */ + check_stack_depth(); + switch (nodeTag(a)) { /* diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c index 5c03e9f2aa..8d9280197b 100644 --- a/src/backend/nodes/outfuncs.c +++ b/src/backend/nodes/outfuncs.c @@ -24,6 +24,7 @@ #include #include "lib/stringinfo.h" +#include "miscadmin.h" #include "nodes/plannodes.h" #include "nodes/relation.h" #include "utils/datum.h" @@ -2941,6 +2942,9 @@ _outConstraint(StringInfo str, const Constraint *node) static void _outNode(StringInfo str, const void *obj) { + /* Guard against stack overflow due to overly complex expressions */ + check_stack_depth(); + if (obj == NULL) appendStringInfoString(str, "<>"); else if (IsA(obj, List) ||IsA(obj, IntList) || IsA(obj, OidList)) diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c index 32b23fff09..a285af302f 100644 --- a/src/backend/nodes/readfuncs.c +++ b/src/backend/nodes/readfuncs.c @@ -28,6 +28,7 @@ #include +#include "miscadmin.h" #include "nodes/parsenodes.h" #include "nodes/readfuncs.h" @@ -1382,6 +1383,9 @@ parseNodeString(void) READ_TEMP_LOCALS(); + /* Guard against stack overflow due to overly complex expressions */ + check_stack_depth(); + token = pg_strtok(&length); #define MATCH(tokname, namelen) \ -- 2.50.1