Description

maurycy

opened on Jul 8, 2026

Issue body actions

Bug report

Bug description:

We've got it in process_frame_chain():

cpython/Modules/_remote_debugging/frames.c

Lines 308 to 326 in 548c731

	const size_t MAX_FRAMES = 1024 + 512;
	size_t frame_count = 0;
	assert(MAX_FRAMES > 0 && MAX_FRAMES < 10000);
	ctx->stopped_at_cached_frame = 0;
	ctx->last_frame_visited = 0;
	while ((void*)frame_addr != NULL) {
	PyObject *frame = NULL;
	uintptr_t next_frame_addr = 0;
	uintptr_t stackpointer = 0;
	last_frame_addr = frame_addr;
	if (++frame_count > MAX_FRAMES) {
	PyErr_SetString(PyExc_RuntimeError, "Too many stack frames (possible infinite loop)");
	set_exception_cause(unwinder, PyExc_RuntimeError, "Frame chain iteration limit exceeded");
	return -1;
	}
	assert(frame_count <= MAX_FRAMES);

There's no such limit in parse_async_frame_chain():

cpython/Modules/_remote_debugging/asyncio.c

Line 937 in c843cb7

process_running_task_chain(

cpython/Modules/_remote_debugging/asyncio.c

Line 767 in c843cb7

parse_async_frame_chain(

cpython/Modules/_remote_debugging/asyncio.c

Line 989 in c843cb7

process_thread_for_async_stack_trace(

CPython versions tested on:

CPython main branch

Operating systems tested on:

macOS

Linked PRs

• gh-153364: Make frame, coroutine, and task-waiter chain walks iterative and bounded #153365
• [3.15] gh-153364: Make frame, coroutine, and task-waiter chain walks iterative and bounded (GH-153365) #158813
• [3.14] gh-153364: Make frame, coroutine, and task-waiter chain walks iterative and bounded (GH-153365) #158814

Activity

1. maurycy

   added

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   on Jul 8, 2026
2. picnixz

   added

   topic-profiling

   extension-modulesC modules in the Modules dirC modules in the Modules dir

   on Jul 9, 2026
3. pablogsal

   added 4 commits that reference this issue on Oct 4, 2026

   gh-153364: Make frame, coroutine, and task-waiter chain walks iterati…

   e0861c6

   [3.15] gh-153364: Make frame, coroutine, and task-waiter chain walks …

   9e401cf

   [3.14] gh-153364: Make frame, coroutine, and task-waiter chain walks …

   f660816

   Revert "[3.15] pythongh-153364: Make frame, coroutine, and task-waite…

   4b5d623
4. StanFromIreland

   closed this as completedon Oct 11, 2026
5. pablogsal

   added a commit that references this issue on Oct 11, 2026

   [3.15] Restore deferred backports for 3.15.1, including GH-158874 (#1…

   4ceb3fa

Issue actions