postgres.git / summary / log / commit / refs

commit    e07ebd4b6e606a7c03ed3c6bf5d6bcbb725247b4
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Sat Aug 13 19:21:28 2022 +0000
First released in: 16.0, 10.23, 11.18, 12.13, 13.9, 14.6, 15.0

    Catch stack overflow when recursing in transformFromClauseItem().
    
    Most parts of the parser can expect that the stack overflow check
    in transformExprRecurse() will trigger before things get desperate.
    However, transformFromClauseItem() can recurse directly to self
    without having analyzed any expressions, so it's possible to drive
    it to a stack-overrun crash.  Add a check to prevent that.
    
    Per bug #17583 from Egor Chindyaskin.  Back-patch to all supported
    branches.
    
    Richard Guo
    
    Discussion: https://postgr.es/m/17583-33be55b9f981f75c@postgresql.org


 src/backend/parser/parse_clause.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c
index 5a18107e799..b85fbebd00e 100644
--- a/src/backend/parser/parse_clause.c
+++ b/src/backend/parser/parse_clause.c
@@ -1050,6 +1050,9 @@ transformFromClauseItem(ParseState *pstate, Node *n,
 						ParseNamespaceItem **top_nsitem,
 						List **namespace)
 {
+	/* Guard against stack overflow due to overly deep subtree */
+	check_stack_depth();
+
 	if (IsA(n, RangeVar))
 	{
 		/* Plain relation reference, or perhaps a CTE reference */


[parent: 8ded65682bee]