From 4a600d76b7e4ec50d0e91da291da4fc9e00deeaf Mon Sep 17 00:00:00 2001 From: Aleksander Alekseev Date: Tue, 16 Jun 2026 15:54:08 +0300 Subject: [PATCH v1 2/2] jsonb_plperl: Replace reference-unwinding loop with recursion SV_to_JsonbValue() used a while loop to dereference chains of Perl references before processing the underlying value. This loop had no protection against circular reference chains (e.g. $x = \$x), causing the backend to spin indefinitely. Replace the loop with a small recursive helper SV_deref() that calls check_stack_depth() on each step. This makes circular and pathologically deep reference chains raise "stack depth limit exceeded" instead of hanging the backend, consistent with how jsonb_plpython handles circular Python object references. Author: Aleksander Alekseev Reviewed-by: TODO FIXME Discussion: TODO FIXME --- contrib/jsonb_plperl/jsonb_plperl.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/contrib/jsonb_plperl/jsonb_plperl.c b/contrib/jsonb_plperl/jsonb_plperl.c index fdcec7760da..40c283d3132 100644 --- a/contrib/jsonb_plperl/jsonb_plperl.c +++ b/contrib/jsonb_plperl/jsonb_plperl.c @@ -176,6 +176,20 @@ HV_to_JsonbValue(HV *obj, JsonbInState *jsonb_state) pushJsonbValue(jsonb_state, WJB_END_OBJECT, NULL); } +/* + * Recursively dereference a Perl reference to reach the underlying value. + * Using recursion rather than a loop lets check_stack_depth() detect + * circular reference chains. + */ +static SV * +SV_deref(SV *in) +{ + check_stack_depth(); + if (SvROK(in)) + return SV_deref(SvRV(in)); + return in; +} + static void SV_to_JsonbValue(SV *in, JsonbInState *jsonb_state, bool is_elem) { @@ -184,9 +198,7 @@ SV_to_JsonbValue(SV *in, JsonbInState *jsonb_state, bool is_elem) check_stack_depth(); - /* Dereference references recursively. */ - while (SvROK(in)) - in = SvRV(in); + in = SV_deref(in); switch (SvTYPE(in)) { -- 2.43.0