SystemError from calling __iter__ on a released memoryview #126341
Description
Crash report
What happened?
The code below causes a SystemError on all tested Python versions in Windows and Linux. In a no-gil debug build of main, besides the expected abort, sometimes a segfault occurs.
from threading import Thread av = memoryview(b"something") av.release() alive = [ Thread(target=av.release, args=('/bin/sh')), Thread(target=av.__iter__, args=()) ] for obj in alive: try: print('START', obj) obj.start() except Exception: passCommon abort:
Fatal Python error: _Py_CheckFunctionResult: a function returned a result with an exception set Python runtime state: initialized ValueError: operation forbidden on released memoryview object The above exception was the direct cause of the following exception: SystemError: <method-wrapper '__iter__' of memoryview object at 0x200006a6050> returned a result with an exception set Aborted Rare segfault:
Exception in thread Thread-1 (release): Fatal Python error: _Py_CheckFunctionResult: a function returned a result with an exception set Python runtime state: initialized ValueError: operation forbidden on released memoryview object The above exception was the direct cause of the following exception: SystemError: <method-wrapper '__iter__' of memoryview object at 0x200006a6050> returned a result with an exception set Current thread 0x00007f750b5d0640 (most recent call first): File "/home/danzin/projects/mycpython/Lib/threading.py", line 992 in run File "/home/danzin/projects/mycpython/Lib/threading.py", line 1041 in _bootstrap_inner File "/home/danzin/projects/mycpython/Lib/threading.py", line 1012 in _bootstrap Thread 0x00007f750bdd5640 (most recent call first): File "<frozen importlib._bootstrap_external>", line 142 in _path_split Python/traceback.c:979:18: runtime error: member access within misaligned address 0x000000000001 for type 'struct _PyInterpreterFrame', which requires 8 byte alignment 0x000000000001: note: pointer points here <memory cannot be printed> Segmentation fault The backtrace for the segfault is:
0x00005555564d6e71 in _PyFrame_GetCode (f=0x7ffff6bbcca8) at ./Include/internal/pycore_frame.h:83 #1 PyUnstable_InterpreterFrame_GetLine ( frame=frame@entry=0x7ffff6bbcca8) at Python/frame.c:146 #2 0x00005555565ffb1e in dump_frame (fd=fd@entry=2, frame=frame@entry=0x7ffff6bbcca8) at Python/traceback.c:905 #3 0x00005555565fffcc in dump_traceback (fd=fd@entry=2, tstate=tstate@entry=0x555557130d20, write_header=write_header@entry=0) at Python/traceback.c:974 #4 0x00005555566001e0 in _Py_DumpTracebackThreads ( fd=fd@entry=2, interp=<optimized out>, interp@entry=0x555557052280 <_PyRuntime+129152>, current_tstate=current_tstate@entry=0x5555571351d0) at Python/traceback.c:1090 #5 0x00005555565888f1 in _Py_FatalError_DumpTracebacks ( fd=fd@entry=2, interp=interp@entry=0x555557052280 <_PyRuntime+129152>, tstate=tstate@entry=0x5555571351d0) at Python/pylifecycle.c:2937 #6 0x000055555659b12b in fatal_error (fd=2, header=header@entry=1, prefix=prefix@entry=0x555556811220 <__func__.23> "_Py_CheckFunctionResult", msg=msg@entry=0x555556810c80 "a function returned a result with an exception set", status=status@entry=-1) at Python/pylifecycle.c:3245 #7 0x000055555659b2ca in _Py_FatalErrorFunc ( func=func@entry=0x555556811220 <__func__.23> "_Py_CheckFunctionResult", msg=msg@entry=0x555556810c80 "a function returned a result with an exception set") at Python/pylifecycle.c:3286 #8 0x0000555555ee822c in _Py_CheckFunctionResult ( tstate=tstate@entry=0x5555571351d0,result=result@entry=0x20004040130, where=where@entry=0x0) at Objects/call.c:65Found using fusil by @vstinner.
CPython versions tested on:
3.11, 3.12, 3.13, CPython main branch
Operating systems tested on:
Linux, Windows
Output from running 'python -VV' on the command line:
No response