use-after-free crash after setting scene's render.engine inside custom render engine context #88404

New Issue

mike w. · 2021-05-19T17:40:55+02:00

mike w. commented

2021-05-19 17:40:55 +02:00

System Information
Operating system: Ubuntu 20.04.2LTS

Blender Version
Broken: 2.93.0 Beta, branch: master, commit date: 2021-05-19 10:14, hash: a294670bac, type: release
Also Broken: 0efb627bbd

Short description of error
Blender crashes when setting some scene's render.engine property inside __init__ or the view_update context of a custom render engine to a different one than the custom engine.

T88404_asan_report.txt
Code to reproduce the error

import bpy
import bgl

class CustomRenderEngine(bpy.types.RenderEngine):
    bl_idname = "CUSTOM"
    bl_label = "Custom"
    bl_use_preview = True
    
    def __init__(self):
        return
        scene = bpy.data.scenes.new("foo")
        scene.render.engine = "CYCLES"
        bpy.data.scenes.remove(scene)

    def __del__(self):
        pass

    def view_update(self, context, depsgraph):
        scene = bpy.data.scenes.new("foo")
        scene.render.engine = "CYCLES"
        bpy.data.scenes.remove(scene)

    def view_draw(self, context, depsgraph):
        pass

def get_panels():
    exclude_panels = {
        'VIEWLAYER_PT_filter',
        'VIEWLAYER_PT_layer_passes',
    }

    panels = []
    for panel in bpy.types.Panel.__subclasses__():
        if hasattr(panel, 'COMPAT_ENGINES') and 'BLENDER_RENDER' in panel.COMPAT_ENGINES:
            if panel.__name__ not in exclude_panels:
                panels.append(panel)

    return panels


def register():
    bpy.utils.register_class(CustomRenderEngine)

    for panel in get_panels():
        panel.COMPAT_ENGINES.add('CUSTOM')


def unregister():
    bpy.utils.unregister_class(CustomRenderEngine)

    for panel in get_panels():
        if 'CUSTOM' in panel.COMPAT_ENGINES:
            panel.COMPAT_ENGINES.remove('CUSTOM')

if __name__ == "__main__":
    register()

Exact steps for others to reproduce the error

Copy code from above into a new script file inside of Blender
Run the script
Select "Custom" as Render Engine inside Render Properties
Select "Material Preview" as display method in the viewport.

crash.blend

Crash log:

# Blender 2.93.0, Commit date: 2021-05-19 10:14, Hash a294670bacb1
Engine 'CUSTOM' not available for scene 'Scene' (an add-on may need to be installed or enabled)  # Error
bpy.ops.text.run_script()  # Operator

# backtrace
./blender(BLI_system_backtrace+0x20) [0xa63c950]
./blender() [0xf6082a]
/lib/x86_64-linux-gnu/libc.so.6(+0x46210) [0x7f7ce17be210]
./blender(GPU_framebuffer_blit+0x2f) [0x8664faf]
./blender() [0x1485fc3]
./blender() [0x14597fe]
./blender(DRW_draw_render_loop_ex+0x242) [0x1459a72]
./blender(view3d_main_region_draw+0x8f) [0x1d3570f]
./blender(ED_region_do_draw+0x851) [0x189c771]
./blender(wm_draw_update+0x52e) [0x130cc9e]
./blender(WM_main+0x30) [0x130aa20]
./blender(main+0x319) [0xe881c9]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf3) [0x7f7ce179f0b3]
./blender() [0xf5d1bc]

# Python backtrace

**System Information** Operating system: Ubuntu 20.04.2LTS **Blender Version** Broken: 2.93.0 Beta, branch: master, commit date: 2021-05-19 10:14, hash: a294670bacb1, type: release Also Broken: 0efb627bbd3ac3e53afb95591ae4e244bd1f8af4 **Short description of error** Blender crashes when setting some scene's render.engine property inside `__init__` or the `view_update` context of a custom render engine to a different one than the custom engine. [T88404_asan_report.txt](https://archive.blender.org/developer/F10165484/T88404_asan_report.txt) **Code to reproduce the error** ``` import bpy import bgl class CustomRenderEngine(bpy.types.RenderEngine): bl_idname = "CUSTOM" bl_label = "Custom" bl_use_preview = True def __init__(self): return scene = bpy.data.scenes.new("foo") scene.render.engine = "CYCLES" bpy.data.scenes.remove(scene) def __del__(self): pass def view_update(self, context, depsgraph): scene = bpy.data.scenes.new("foo") scene.render.engine = "CYCLES" bpy.data.scenes.remove(scene) def view_draw(self, context, depsgraph): pass def get_panels(): exclude_panels = { 'VIEWLAYER_PT_filter', 'VIEWLAYER_PT_layer_passes', } panels = [] for panel in bpy.types.Panel.__subclasses__(): if hasattr(panel, 'COMPAT_ENGINES') and 'BLENDER_RENDER' in panel.COMPAT_ENGINES: if panel.__name__ not in exclude_panels: panels.append(panel) return panels def register(): bpy.utils.register_class(CustomRenderEngine) for panel in get_panels(): panel.COMPAT_ENGINES.add('CUSTOM') def unregister(): bpy.utils.unregister_class(CustomRenderEngine) for panel in get_panels(): if 'CUSTOM' in panel.COMPAT_ENGINES: panel.COMPAT_ENGINES.remove('CUSTOM') if __name__ == "__main__": register() ``` **Exact steps for others to reproduce the error** 1) Copy code from above into a new script file inside of Blender 2) Run the script 3) Select "Custom" as Render Engine inside Render Properties 4) Select "Material Preview" as display method in the viewport. [crash.blend](https://archive.blender.org/developer/F10127097/crash.blend) Crash log: ``` # Blender 2.93.0, Commit date: 2021-05-19 10:14, Hash a294670bacb1 Engine 'CUSTOM' not available for scene 'Scene' (an add-on may need to be installed or enabled) # Error bpy.ops.text.run_script() # Operator # backtrace ./blender(BLI_system_backtrace+0x20) [0xa63c950] ./blender() [0xf6082a] /lib/x86_64-linux-gnu/libc.so.6(+0x46210) [0x7f7ce17be210] ./blender(GPU_framebuffer_blit+0x2f) [0x8664faf] ./blender() [0x1485fc3] ./blender() [0x14597fe] ./blender(DRW_draw_render_loop_ex+0x242) [0x1459a72] ./blender(view3d_main_region_draw+0x8f) [0x1d3570f] ./blender(ED_region_do_draw+0x851) [0x189c771] ./blender(wm_draw_update+0x52e) [0x130cc9e] ./blender(WM_main+0x30) [0x130aa20] ./blender(main+0x319) [0xe881c9] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf3) [0x7f7ce179f0b3] ./blender() [0xf5d1bc] # Python backtrace ```

mike w. commented

2021-05-19 17:40:55 +02:00

Added subscriber: @mikewazowski11

Moritz Brückner commented

2021-05-19 17:48:12 +02:00

Added subscriber: @timodriaan

Ankit Meel changed title from ~~Crash after setting scene's render.engine inside custom render engine context~~ to use-after-free crash after setting scene's render.engine inside custom render engine context

2021-06-10 12:09:17 +02:00

Ankit Meel commented

2021-06-10 12:09:17 +02:00

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

Ankit Meel commented

2021-06-10 12:09:22 +02:00

Added subscriber: @ankitm

Philipp Oeser removed the

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use-after-free crash after setting scene's render.engine inside custom render engine context #88404