segfault with improper use of super() #17728
Description
Port, board and/or hardware
unix, coverage build
MicroPython version
MicroPython v1.26.0-preview.387.ge4e97f5aa7.dirty on 2025-07-20; linux [GCC 12.2.0] version
Reproduction
Run the following code:
import framebuf
class FB(framebuf.FrameBuffer):
def __init__(self, n):
self = n
super().__init__(bytearray(2 * n * n), n, n, framebuf.RGB565)
fb = FB(n=3)
Expected behaviour
super() should not segfault.
Observed behaviour
crash in native_base_init_wrapper
Program received signal SIGSEGV, Segmentation fault.
0x00005555556120c7 in native_base_init_wrapper (n_args=5, args=0x7fffffffd6c0,
kw_args=0x7fffffffd510) at ../../py/objtype.c:91
91 instance_count_native_bases(self->base.type, &native_base);
(gdb) p self
$1 = (mp_obj_instance_t *) 0x7
Additional Information
This is a minimized version of a script produced by fuzzing micropython.
Code of Conduct
Yes, I agree