fix(profiling): upper bound on iterations for TaskInfo::unwind [backport 4.5]

ddtrace/internal/datadog/profiling/stack/src/echion/tasks.cc

@@ -170,9 +170,16 @@ TaskInfo::unwind(EchionSampler& echion, FrameStack& stack, bool using_uvloop)
     std::stack<PyObject*, std::vector<PyObject*>> coro_frames;
 
     // Unwind the coro chain
+    size_t coro_chain_depth = 0;
     for (auto py_coro = this->coro.get(); py_coro != NULL; py_coro = py_coro->await.get()) {
-        if (py_coro->frame != NULL)
+        coro_chain_depth++;
+        if (coro_chain_depth > MAX_RECURSION_DEPTH) {
+            break;
+        }
+
+        if (py_coro->frame != NULL) {
             coro_frames.push(py_coro->frame);
+        }
     }
 
     // Total number of frames added to the Stack

ddtrace/internal/datadog/profiling/stack/src/echion/threads.cc

@@ -211,7 +211,12 @@ ThreadInfo::unwind_tasks(EchionSampler& echion, PyThreadState* tstate)
         auto stack_info = std::make_unique<StackInfo>(leaf_task.get().name, leaf_task.get().is_on_cpu);
         auto& stack = stack_info->stack;
 
+        // Safety: prevent infinite loops from cycles in task chain maps
+        size_t task_chain_depth = 0;
         for (auto current_task = leaf_task;;) {
+            if (++task_chain_depth > MAX_RECURSION_DEPTH) {
+                break;
+            }
             auto& task = current_task.get();
 
             auto task_stack_size = task.unwind(echion, stack, using_uvloop);

releasenotes/notes/profiling-fix-max-iterations-unwind-tasks-671d743912c7d600.yaml

@@ -0,0 +1,4 @@
+fixes:
+  - |
+    profiling: A bug where the Stack Profiler could loop infinitely (and allocate large amounts of memory,
+    leading to crashes) when sampling ``asyncio`` Tasks has been fixed.