App crash: corrupted size vs. prev_size in fastbins

LeBeef

Dear community,

I am running a PySide6 app. It has a idle view with a looping video in the background. The application runs 24h a day. 2 or 3 times a day the application crashes without any interaction with the flowing messages:

QML: Error transferring the data to system memory: -5
QML: Cannot map a video frame in ReadOnly mode!
corrupted size vs. prev_size in fastbins

This is the backtrace:

Thread 61 "QSGRenderThread" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fff27fff640 (LWP 8354)]
0x00007ffff66accd1 in __dynamic_cast () from /lib/x86_64-linux-gnu/libstdc++.so.6
(gdb) bt
#0  0x00007ffff66accd1 in __dynamic_cast () from /lib/x86_64-linux-gnu/libstdc++.so.6
#1  0x00007fff4ab23376 in ?? () from /usr/lib/x86_64-linux-gnu/dri/iHD_drv_video.so
#2  0x00007fff4ab2a241 in ?? () from /usr/lib/x86_64-linux-gnu/dri/iHD_drv_video.so
#3  0x00007fffa8017e84 in vaSyncSurface () from /lib/x86_64-linux-gnu/libva.so.2
#4  0x00007fff864ace48 in ?? () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/plugins/multimedia/libffmpegmediaplugin.so
#5  0x00007fff864ad3aa in ?? () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/plugins/multimedia/libffmpegmediaplugin.so
#6  0x00007fff864a8d33 in ?? () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/plugins/multimedia/libffmpegmediaplugin.so
#7  0x00007fff864a8dc7 in ?? () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/plugins/multimedia/libffmpegmediaplugin.so
#8  0x00007fff8594cfb3 in ?? () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/plugins/multimedia/libffmpegmediaplugin.so
#9  0x00007fffc0093149 in QVideoFrame::map(QVideoFrame::MapMode) () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/qml/QtMultimedia/../../lib/libQt6Multimedia.so.6
#10 0x00007fffc00970fc in QVideoTextureHelper::createTextures(QVideoFrame&, QRhi*, QRhiResourceUpdateBatch*, std::unique_ptr<QVideoFrameTextures, std::default_delete<QVideoFrameTextures> >&&) ()
   from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/qml/QtMultimedia/../../lib/libQt6Multimedia.so.6
#11 0x00007fffd0035d78 in ?? () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/qml/QtMultimedia/../../lib/libQt6MultimediaQuick.so.6
#12 0x00007fffd0035f1b in ?? () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/qml/QtMultimedia/../../lib/libQt6MultimediaQuick.so.6
#13 0x00007fffef6d29fb in QSGBatchRenderer::Renderer::updateMaterialDynamicData(QSGBatchRenderer::ShaderManagerShader*, QSGMaterialShader::RenderState&, QSGMaterial*, QSGBatchRenderer::Batch const*, QSGBatchRenderer::Element*, int, int) () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/lib/libQt6Quick.so.6
#14 0x00007fffef6d4d1c in ?? () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/lib/libQt6Quick.so.6
#15 0x00007fffef6d5cfe in QSGBatchRenderer::Renderer::prepareRenderPass(QSGBatchRenderer::Renderer::RenderPassContext*) ()
   from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/lib/libQt6Quick.so.6
#16 0x00007fffef6d7963 in QSGBatchRenderer::Renderer::render() () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/lib/libQt6Quick.so.6
#17 0x00007fffef6edc42 in QSGRenderer::renderScene() () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/lib/libQt6Quick.so.6
#18 0x00007fffef692d8e in QQuickWindowPrivate::renderSceneGraph() () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/lib/libQt6Quick.so.6
#19 0x00007fffef87c03d in ?? () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/lib/libQt6Quick.so.6
#20 0x00007fffef87d577 in ?? () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/lib/libQt6Quick.so.6
#21 0x00007ffff5afc66d in ?? () from /home/deploy/devel/0095/.venv/lib/python3.12/site-packages/PySide6/Qt/lib/libQt6Core.so.6
#22 0x00007ffff7494ac3 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
#23 0x00007ffff7526850 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Environment:

$ cat /etc/lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=22.04
DISTRIB_CODENAME=jammy
DISTRIB_DESCRIPTION="Ubuntu 22.04.4 LTS"
(venv) $ python -V
Python 3.12.3
(venv) $ pip list
Package            Version
------------------ --------
annotated-types    0.7.0
certifi            2024.6.2
pip                24.1
pydantic           2.7.4
pydantic_core      2.18.4
PySide6            6.7.2
PySide6_Addons     6.7.2
PySide6_Essentials 6.7.2
sentry-sdk         2.6.0
setuptools         70.1.0
shiboken6          6.7.2
typing_extensions  4.12.2
urllib3            2.2.2

The qml snippet:

Video {
    id: bgVideo
    anchors.fill: parent
    autoPlay: true
    loops: MediaPlayer.Infinite
    source: "idle_animation.mp4"
}

You you have an idea what could cause those crashes?

Kind regards

Nils

SGaist

Hi,

Did you try to check system logs to see if there was something wrong going on ?
What about memory used by your application ?

LeBeef

Hi @SGaist,

fortunately we are logging all the pc resources, but there was nothing unusual during the crash and nothing unusual in syslog. Another error I saw around the crash is this:

[AVHWFramesContext @ 0x7f7b28051180] Failed to sync surface 0x3f: 1 (operation failed).

SGaist

What about dmesg ?

LeBeef

@SGaist said in App crash: corrupted size vs. prev_size in fastbins:

dmesg

Unfortunately no messages related to the crashes.

SGaist

Strange...
What is your video hardware ?

LeBeef

@SGaist We have our app running on two different systems. One has a Nvidia GPU and one has intel graphics. It happens only on the one with intel graphics. Here are the details:

        *-display
             description: VGA compatible controller
             product: Alder Lake-P Integrated Graphics Controller
             vendor: Intel Corporation
             physical id: 2
             bus info: pci@0000:00:02.0
             logical name: /dev/fb0
             version: 0c
             width: 64 bits
             clock: 33MHz
             capabilities: pciexpress msi pm vga_controller bus_master cap_list rom fb
             configuration: depth=32 driver=i915 latency=0 mode=1920x1080 resolution=1920,1080 visual=truecolor xres=1920 yres=1080
             resources: iomemory:600-5ff iomemory:400-3ff irq:165 memory:6000000000-6000ffffff memory:4000000000-400fffffff ioport:3000(size=64) memory:c0000-dffff memory:4010000000-4016ffffff memory:4020000000-40ffffffff

LeBeef

PS: It happens on multiple instances of intel, which playback different video files.

SGaist

Ok, so at least there's some common point of failure.

Which backend are you using ?

LeBeef

@SGaist Since I did not set anything with an ENV var I guess it is using ffmpeg right?

SGaist

Since you are using 6.7, that should be the default yes.

You can check that by setting the QT_DEBUG_PLUGINS environment variable to 1 in the terminal where you start your application.