diff --git a/Zend/tests/gh22521.phpt b/Zend/tests/gh22521.phpt
new file mode 100644
index 000000000000..a5e91ded5a8f
--- /dev/null
+++ b/Zend/tests/gh22521.phpt
@@ -0,0 +1,24 @@
+--TEST--
+GH-22521: Infinite recursion inside try/catch should not crash unpredictably
+--INI--
+memory_limit=8G
+--SKIPIF--
+<?php
+if (!getenv('RUN_RESOURCE_HEAVY_TESTS')) die('skip resource-heavy test');
+if (getenv('SKIP_SLOW_TESTS')) die('skip slow test');
+if (PHP_INT_SIZE != 8) die('skip 64-bit only');
+?>
+--FILE--
+<?php
+try {
+    function foo() {
+        foo();
+    }
+    foo();
+} catch (\Throwable $_ffl_e) {
+    echo "Caught throwable\n";
+}
+echo "End\n";
+?>
+--EXPECTF--
+Fatal error: Allowed memory size of %d bytes exhausted at %s:%d (tried to allocate %d bytes) in %s on line %d
diff --git a/Zend/zend_builtin_functions.c b/Zend/zend_builtin_functions.c
index 2dceac2512db..16e740eec4aa 100644
--- a/Zend/zend_builtin_functions.c
+++ b/Zend/zend_builtin_functions.c
@@ -1940,6 +1940,9 @@ ZEND_API void zend_fetch_debug_backtrace(zval *return_value, int skip_last, int
 		/* For frameless calls we add an additional frame for the call itself. */
 		if (ZEND_USER_CODE(call->func->type)) {
 			const zend_op *opline = call->opline;
+			if (UNEXPECTED(!opline)) {
+				goto not_frameless_call; 
+			}
 			if (!ZEND_OP_IS_FRAMELESS_ICALL(opline->opcode)) {
 				goto not_frameless_call;
 			}