bl_description = None triggers segfault on register. #86983

New Issue

Will · 2021-03-27T20:08:11+01:00

Will commented

2021-03-27 20:08:11 +01:00

System Information
Operating system: Linux
Graphics card: Intel

Blender Version
Broken:

2.93
2.92
2.91.x
2.83.x

Worked:

Never

Short description of error

Trying to register an operator class with bl_description = None causes a segfault.

bl_idname = None and bl_label = None both raise warnings instead of crashing. Also, there seems to be some equivalence/interchangeability for setting descriptions using __doc__ instead of bl_description— The default value of which is None. So I think it could be nice to handle this case gracefully.

Exact steps for others to reproduce the error

Define any operator class.
Set bl_description = None in that operator class's class attributes.
Try to register that operator class.

Example:

import bpy

class CrashOperator(bpy.types.Operator):
	bl_idname = "object.crash_operator"
	bl_label = "Crash Operator"
	bl_description = None

bpy.utils.register_class(CrashOperator)

**System Information** Operating system: Linux Graphics card: Intel **Blender Version** Broken: - 2.93 - 2.92 - 2.91.x - 2.83.x Worked: - Never **Short description of error** Trying to register an operator class with `bl_description = None` causes a segfault. `bl_idname = None` and `bl_label = None` both raise warnings instead of crashing. Also, there seems to be some equivalence/interchangeability for setting descriptions using `__doc__` instead of `bl_description`— The default value of which is `None`. So I think it could be nice to handle this case gracefully. **Exact steps for others to reproduce the error** * Define any operator class. * Set `bl_description = None` in that operator class's class attributes. * Try to register that operator class. Example: ``` import bpy class CrashOperator(bpy.types.Operator): bl_idname = "object.crash_operator" bl_label = "Crash Operator" bl_description = None bpy.utils.register_class(CrashOperator) ```

Will commented

2021-03-27 20:08:11 +01:00

Added subscriber: @WCN

Robert Guetzkow commented

2021-03-28 00:26:48 +01:00

Added subscriber: @rjg

Robert Guetzkow commented

2021-03-28 00:26:48 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Robert Guetzkow commented

2021-03-28 00:26:48 +01:00

I can confirm this crash.

BLI_strnlen(const unsigned char * s, const unsigned __int64 maxlen) Line 860	C
BLI_strncpy(unsigned char * dst, const unsigned char * src, const unsigned __int64 maxncpy) Line 110	C
rna_Operator_bl_description_set(PointerRNA * ptr, const unsigned char * value) Line 1802	C
Operator_bl_description_set(PointerRNA * ptr, const unsigned char * value) Line 697	C
RNA_property_string_set(PointerRNA * ptr, PropertyRNA * prop, const unsigned char * value) Line 3415	C
pyrna_py_to_prop(PointerRNA * ptr, PropertyRNA * prop, void * data, _object * value, const unsigned char * error_prefix) Line 1826	C
bpy_class_validate_recursive(PointerRNA * dummyptr, StructRNA * srna, void * py_data, int * have_function) Line 8355	C
bpy_class_validate(PointerRNA * dummyptr, void * py_data, int * have_function) Line 8369	C
rna_Operator_register(Main * bmain, ReportList * reports, void * data, const unsigned char * identifier, int(*)(PointerRNA *, void *, int *) validate, int(*)(bContext *, PointerRNA *, FunctionRNA *, ParameterList *) call, void(*)(void *) free) Line 1512	C
pyrna_register_class(_object * UNUSED_self, _object * py_class) Line 8888	C

I can confirm this crash. ```lines BLI_strnlen(const unsigned char * s, const unsigned __int64 maxlen) Line 860 C BLI_strncpy(unsigned char * dst, const unsigned char * src, const unsigned __int64 maxncpy) Line 110 C rna_Operator_bl_description_set(PointerRNA * ptr, const unsigned char * value) Line 1802 C Operator_bl_description_set(PointerRNA * ptr, const unsigned char * value) Line 697 C RNA_property_string_set(PointerRNA * ptr, PropertyRNA * prop, const unsigned char * value) Line 3415 C pyrna_py_to_prop(PointerRNA * ptr, PropertyRNA * prop, void * data, _object * value, const unsigned char * error_prefix) Line 1826 C bpy_class_validate_recursive(PointerRNA * dummyptr, StructRNA * srna, void * py_data, int * have_function) Line 8355 C bpy_class_validate(PointerRNA * dummyptr, void * py_data, int * have_function) Line 8369 C rna_Operator_register(Main * bmain, ReportList * reports, void * data, const unsigned char * identifier, int(*)(PointerRNA *, void *, int *) validate, int(*)(bContext *, PointerRNA *, FunctionRNA *, ParameterList *) call, void(*)(void *) free) Line 1512 C pyrna_register_class(_object * UNUSED_self, _object * py_class) Line 8888 C ```

Robert Guetzkow commented

2021-03-28 00:46:23 +01:00

In rna_wm.c, rna_def_operator(BlenderRNA *brna) it clears the PROP_NEVER_NULL flag. Either this needs to be changed to enforce that it is never null or the validation needs to be improved.

  prop = RNA_def_property(srna, "bl_description", PROP_STRING, PROP_NONE);
  RNA_def_property_string_sdna(prop, NULL, "type->description");
  RNA_def_property_string_maxlength(prop, RNA_DYN_DESCR_MAX); /* else it uses the pointer size! */
  RNA_def_property_string_funcs(prop, NULL, NULL, "rna_Operator_bl_description_set");
  /* RNA_def_property_clear_flag(prop, PROP_EDITABLE); */
  RNA_def_property_flag(prop, PROP_REGISTER_OPTIONAL);
  RNA_def_property_clear_flag(prop, PROP_NEVER_NULL); /* check for NULL */

In `rna_wm.c`, `rna_def_operator(BlenderRNA *brna)` it clears the `PROP_NEVER_NULL` flag. Either this needs to be changed to enforce that it is never null or the validation needs to be improved. ``` prop = RNA_def_property(srna, "bl_description", PROP_STRING, PROP_NONE); RNA_def_property_string_sdna(prop, NULL, "type->description"); RNA_def_property_string_maxlength(prop, RNA_DYN_DESCR_MAX); /* else it uses the pointer size! */ RNA_def_property_string_funcs(prop, NULL, NULL, "rna_Operator_bl_description_set"); /* RNA_def_property_clear_flag(prop, PROP_EDITABLE); */ RNA_def_property_flag(prop, PROP_REGISTER_OPTIONAL); RNA_def_property_clear_flag(prop, PROP_NEVER_NULL); /* check for NULL */ ```

Campbell Barton self-assigned this 2021-03-29 12:25:50 +02:00

blender-admin commented

2021-03-29 12:47:16 +02:00

This issue was referenced by e0ce76f1c5

This issue was referenced by e0ce76f1c5eb70ab66755dce4627b918fc102cbd

Campbell Barton commented

2021-03-29 13:11:10 +02:00

Changed status from 'Confirmed' to: 'Resolved'

Campbell Barton closed this issue

2021-03-29 13:11:10 +02:00

Sign in to join this conversation.

No Label

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

bl_description = None triggers segfault on register. #86983

`bl_description = None` triggers segfault on register. #86983