← index #17714Issue #17728
Off-topic · high · value 3.193
QUERY · ISSUE

virtpin: crash with improper usage

openby jepleropened 2025-07-19updated 2025-07-19
bug

Port, board and/or hardware

unix port, longlong variant

MicroPython version

MicroPython v1.26.0-preview.389.gb795cd238a.dirty

Reproduction

Pass a wrong object to the first argument of time_pulse_us:

$ build-longlong/micropython  -c 'import machine; machine.time_pulse_us(object(), 1)'
Segmentation fault

Expected behaviour

An exception is raised

Observed behaviour

Program received signal SIGSEGV, Segmentation fault.
0x000055555564b0be in mp_virtual_pin_read (pin=pin@entry=0x7ffff7c45b80)
    at ../../extmod/virtpin.c:32
32	    return pin_p->ioctl(pin, MP_PIN_READ, 0, NULL);

Additional Information

This finding is based on fuzzing micropython. I manually minimized the test case it provided.

Code of Conduct

Yes, I agree

CANDIDATE · ISSUE

segfault with improper use of super()

openby jepleropened 2025-07-20updated 2025-07-20
bug

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

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