diff --git a/Misc/NEWS.d/next/Library/2026-02-03-19-57-41.gh-issue-144316.wop870.rst b/Misc/NEWS.d/next/Library/2026-02-03-19-57-41.gh-issue-144316.wop870.rst new file mode 100644 index 00000000000000..b9d0749f56ba6a --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-02-03-19-57-41.gh-issue-144316.wop870.rst @@ -0,0 +1 @@ +Fix crash in ``_remote_debugging`` that caused ``test_external_inspection`` to intermittently fail. Patch by Taegyun Kim. diff --git a/Modules/_remote_debugging/_remote_debugging.h b/Modules/_remote_debugging/_remote_debugging.h index 78add74423b608..7bcb2f483234ec 100644 --- a/Modules/_remote_debugging/_remote_debugging.h +++ b/Modules/_remote_debugging/_remote_debugging.h @@ -29,6 +29,7 @@ extern "C" { #include "internal/pycore_interpframe.h" // FRAME_OWNED_BY_INTERPRETER #include "internal/pycore_llist.h" // struct llist_node #include "internal/pycore_long.h" // _PyLong_GetZero +#include "internal/pycore_pyerrors.h" // _PyErr_FormatFromCause #include "internal/pycore_stackref.h" // Py_TAG_BITS #include "../../Python/remote_debug.h" @@ -173,10 +174,13 @@ typedef enum _WIN32_THREADSTATE { #define THREAD_STATUS_HAS_EXCEPTION (1 << 4) /* Exception cause macro */ -#define set_exception_cause(unwinder, exc_type, message) \ - if (unwinder->debug) { \ - _set_debug_exception_cause(exc_type, message); \ - } +#define set_exception_cause(unwinder, exc_type, message) \ + do { \ + assert(PyErr_Occurred() && "function returned -1 without setting exception"); \ + if (unwinder->debug) { \ + _set_debug_exception_cause(exc_type, message); \ + } \ + } while (0) /* ============================================================================ * TYPE DEFINITIONS diff --git a/Modules/_remote_debugging/asyncio.c b/Modules/_remote_debugging/asyncio.c index 3fcc939fd0e876..5385b42f1713ec 100644 --- a/Modules/_remote_debugging/asyncio.c +++ b/Modules/_remote_debugging/asyncio.c @@ -117,6 +117,7 @@ iterate_set_entries( // Validate mask and num_els to prevent huge loop iterations from garbage data if (mask < 0 || mask >= MAX_SET_TABLE_SIZE || num_els < 0 || num_els > mask + 1) { + PyErr_SetString(PyExc_RuntimeError, "Invalid set object (corrupted remote memory)"); set_exception_cause(unwinder, PyExc_RuntimeError, "Invalid set object (corrupted remote memory)"); return -1; diff --git a/Modules/_remote_debugging/code_objects.c b/Modules/_remote_debugging/code_objects.c index 9b7b4dc22b873b..91f7a02005391a 100644 --- a/Modules/_remote_debugging/code_objects.c +++ b/Modules/_remote_debugging/code_objects.c @@ -446,6 +446,9 @@ parse_code_object(RemoteUnwinderObject *unwinder, if (tlbc_entry) { // Validate index bounds (also catches negative values since tlbc_index is signed) if (ctx->tlbc_index < 0 || ctx->tlbc_index >= tlbc_entry->tlbc_array_size) { + PyErr_Format(PyExc_RuntimeError, + "Invalid tlbc_index %d (array size %zd, corrupted remote memory)", + ctx->tlbc_index, tlbc_entry->tlbc_array_size); set_exception_cause(unwinder, PyExc_RuntimeError, "Invalid tlbc_index (corrupted remote memory)"); goto error; diff --git a/Modules/_remote_debugging/frames.c b/Modules/_remote_debugging/frames.c index 02c48205b85a37..2ace0c0f7676ae 100644 --- a/Modules/_remote_debugging/frames.c +++ b/Modules/_remote_debugging/frames.c @@ -49,6 +49,8 @@ process_single_stack_chunk( // Size must be at least enough for the header and reasonably bounded if (actual_size <= offsetof(_PyStackChunk, data) || actual_size > MAX_STACK_CHUNK_SIZE) { PyMem_RawFree(this_chunk); + PyErr_Format(PyExc_RuntimeError, + "Invalid stack chunk size %zu (corrupted remote memory)", actual_size); set_exception_cause(unwinder, PyExc_RuntimeError, "Invalid stack chunk size (corrupted remote memory)"); return -1; @@ -244,6 +246,7 @@ parse_frame_from_chunks( ) { void *frame_ptr = find_frame_in_chunks(chunks, address); if (!frame_ptr) { + PyErr_Format(PyExc_RuntimeError, "Frame at address 0x%lx not found in stack chunks", address); set_exception_cause(unwinder, PyExc_RuntimeError, "Frame not found in stack chunks"); return -1; } diff --git a/Modules/_remote_debugging/module.c b/Modules/_remote_debugging/module.c index 26ebed13098f0e..040bd3db377315 100644 --- a/Modules/_remote_debugging/module.c +++ b/Modules/_remote_debugging/module.c @@ -595,6 +595,9 @@ _remote_debugging_RemoteUnwinder_get_stack_trace_impl(RemoteUnwinderObject *self // Detect cycle: if current_tstate didn't advance, we have corrupted data if (current_tstate == prev_tstate) { Py_DECREF(interpreter_threads); + PyErr_Format(PyExc_RuntimeError, + "Thread list cycle detected at address 0x%lx (corrupted remote memory)", + current_tstate); set_exception_cause(self, PyExc_RuntimeError, "Thread list cycle detected (corrupted remote memory)"); Py_CLEAR(result); diff --git a/Python/remote_debug.h b/Python/remote_debug.h index dba6da3bad4197..6c45a7e455d5bb 100644 --- a/Python/remote_debug.h +++ b/Python/remote_debug.h @@ -1263,6 +1263,7 @@ _Py_RemoteDebug_PagedReadRemoteMemory(proc_handle_t *handle, if (entry->data == NULL) { entry->data = PyMem_RawMalloc(page_size); if (entry->data == NULL) { + PyErr_NoMemory(); _set_debug_exception_cause(PyExc_MemoryError, "Cannot allocate %zu bytes for page cache entry " "during read from PID %d at address 0x%lx", @@ -1272,7 +1273,7 @@ _Py_RemoteDebug_PagedReadRemoteMemory(proc_handle_t *handle, } if (_Py_RemoteDebug_ReadRemoteMemory(handle, page_base, page_size, entry->data) < 0) { - // Try to just copy the exact ammount as a fallback + // Try to just copy the exact amount as a fallback PyErr_Clear(); goto fallback; }