Bug 511948

Summary:	kwin_wayland SIGSEGV in QObjectPrivate::deleteChildren (Qt6) randomly when closing windows
Product:	[Plasma] kwin	Reporter:	Bohdan Kryzhov <aidvache>
Component:	generic-crash	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	crash	CC:	higors88, kdedev
Priority:	NOR
Version First Reported In:	6.5.80
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
See Also:	https://bugs.kde.org/show_bug.cgi?id=512403
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Bohdan Kryzhov 2025-11-11 06:34:57 UTC

SUMMARY

kwin\_wayland crash (Breeze/animations) causes full session failure, killing plasmashell and all open applications.

STEPS TO REPRODUCE

1.  Log into a Plasma Wayland session.
2.  Use the system normally (opening, closing, minimizing, moving windows).
3.  The crash occurs randomly, often without a specific, repeatable trigger.

OBSERVED RESULT

The `kwin_wayland` process crashes (see stack trace below). This triggers a catastrophic failure of the entire Plasma session.

1.  `plasmashell` also crashes: the panel, tray icons (including the battery widget), and all desktop widgets disappear.
2.  All open applications (e.g., browser, terminal, text editor) are immediately terminated, and all their windows are lost.
3.  The session effectively restarts from scratch, showing a black screen before `plasmashell` and the desktop reload.

EXPECTED RESULT

`kwin_wayland` should run stably. Even if it crashes, it should restart without terminating `plasmashell` or any other user applications.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: CachyOS (Arch-based)
KDE Plasma Version: 6.5.2
KDE Frameworks Version: 6.19.0
Qt Version: 6.10.0
Kernel Version: 6.18.0-rc4-2-cachyos-rc-lto (64-bit)
Graphics Platform: Wayland
Processors: 8 × AMD Ryzen 5 7235HS
Memory: 16 GiB of RAM (15.3 GiB usable)
Graphics Processor: NVIDIA GeForce RTX 3050 6GB Laptop GPU

**ADDITIONAL INFORMATION**

The system is a Lenovo LOQ 15ARP9 laptop.

The `kwin_wayland` crash (stack trace below) appears to be the trigger for this full session crash. The stack trace points to `org.kde.breeze.so` (the Breeze window decoration) and `QAbstractAnimation` during object destruction.

At boot, the kernel log also shows several ACPI BIOS errors related to the NVIDIA device (`NVD1`):

```
лис 11 07:20:12 cachyos kernel: ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PCI0.GPP0.PEGP.GPS.NVD1], AE_NOT_FOUND (20250807/psargs-332)
лис 11 07:20:12 cachyos kernel: ACPI Error: Aborting method \_SB.PCI0.GPP0.PEGP.GPS due to previous error (AE_NOT_FOUND) (20250807/psparse-531)
лис 11 07:20:12 cachyos kernel: ACPI Error: Aborting method \_SB.PCI0.GPP0.PEGP._DSM due to previous error (AE_NOT_FOUND) (20250807/psparse-531)
```

Full coredump stack trace for the `kwin_wayland` crash:

```
лис 11 08:22:14 cachyos systemd-coredump[8039]: [🡕] Process 864 (kwin_wayland) of user 1000 dumped core.

                                                   Stack trace of thread 864:
                                                   #0  0x00007f7e641bc029 _ZNK14QObjectPrivate17isSignalConnectedEjb (libQt6Core.so.6 + 0x1bc029)
                                                   #1  0x00007f7e641c33d7 _ZN7QObjectD2Ev (libQt6Core.so.6 + 0x1c33d7)
                                                   #2  0x00007f7e643070fc _ZN18QAbstractAnimationD1Ev (libQt6Core.so.6 + 0x3070fc)
                                                   #3  0x00007f7e64315bff _ZN17QVariantAnimationD0Ev (libQt6Core.so.6 + 0x315bff)
                                                   #4  0x00007f7e641bc6e2 _ZN14QObjectPrivate14deleteChildrenEv (libQt6Core.so.6 + 0x1bc6e2)
                                                   #5  0x00007f7e641c339e _ZN7QObjectD2Ev (libQt6Core.so.6 + 0x1c339e)
                                                   #6  0x00007f7e589e745d n/a (org.kde.breeze.so + 0xb45d)
                                                   #7  0x00007f7e641bc6e2 _ZN14QObjectPrivate14deleteChildrenEv (libQt6Core.so.6 + 0x1bc6e2)
                                                   #8  0x00007f7e641c339e _ZN7QObjectD2Ev (libQt6Core.so.6 + 0x1c339e)
                                                   #9  0x00007f7e671a9d53 _ZN12KDecoration321DecorationButtonGroupD0Ev (libkdecorations3.so.6 + 0x1fd53)
                                                   #10 0x00007f7e641bc6e2 _ZN14QObjectPrivate14deleteChildrenEv (libQt6Core.so.6 + 0x1bc6e2)
                                                   #11 0x00007f7e641c339e _ZN7QObjectD2Ev (libQt6Core.so.6 + 0x1c339e)
                                                   #12 0x00007f7e589e7cda n/a (org.kde.breeze.so + 0xbcda)
                                                   #13 0x00007f7e66976da7 n/a (libkwin.so.6 + 0x176da7)
                                                   #14 0x00007f7e66c508f9 _ZN4KWin6WindowD1Ev (libkwin.so.6 + 0x4508f9)
                                                   #15 0x00007f7e66c9da82 n/a (libkwin.so.6 + 0x49da82)
                                                   #16 0x00007f7e66a1729a _ZN4KWin15AnimationEffect15postPaintScreenEv (libkwin.so.6 + 0x21729a)
                                                   #17 0x00007f7e66a1a514 _ZN4KWin14EffectsHandler15postPaintScreenEv (libkwin.so.6 + 0x21a514)
                                                   #18 0x00007f7e66a1a514 _ZN4KWin14EffectsHandler15postPaintScreenEv (libkwin.so.6 + 0x21a514)
                                                   #19 0x00007f7e66b76c5b _ZN4KWin9SceneView9postPaintEv (libkwin.so.6 + 0x376c5b)
                                                   #20 0x00007f7e6699353c _ZN4KWin10Compositor9compositeEPNS_10RenderLoopE (libkwin.so.6 + 0x19353c)
                                                   #21 0x00007f7e641d716f n/a (libQt6Core.so.6 + 0x1d716f)
                                                   #22 0x00007f7e669bc5c7 _ZN4KWin10RenderLoop14frameRequestedEPS0_ (libkwin.so.6 + 0x1bc5c7)
```

Comment 1 Bohdan Kryzhov 2025-11-11 16:16:06 UTC

Crashed after try to launch winboat.
-- journalctl -p 3 -b
лис 11 18:13:19 cachyos kernel:
лис 11 18:13:19 cachyos kernel: ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PCI0.GPP0.PEGP.GPS.NVD1], AE_NOT_FOUND (20250807/psargs-332)
лис 11 18:13:19 cachyos kernel: ACPI Error: Aborting method \_SB.PCI0.GPP0.PEGP.GPS due to previous error (AE_NOT_FOUND) (20250807/psparse-531)
лис 11 18:13:19 cachyos kernel: ACPI Error: Aborting method \_SB.PCI0.GPP0.PEGP._DSM due to previous error (AE_NOT_FOUND) (20250807/psparse-531)
лис 11 18:13:44 cachyos systemd-coredump[3477]: [🡕] Process 949 (kwin_wayland) of user 1000 dumped core.

                                                   Stack trace of thread 949:
                                                   #0  0x00007f6eea88758b n/a (libnvidia-eglcore.so.580.105.08 + 0xa8758b)
                                                   #1  0x00007f6eea8876e0 n/a (libnvidia-eglcore.so.580.105.08 + 0xa876e0)
                                                   #2  0x00007f6eea888c32 n/a (libnvidia-eglcore.so.580.105.08 + 0xa88c32)
                                                   #3  0x00007f6eea83b47f n/a (libnvidia-eglcore.so.580.105.08 + 0xa3b47f)
                                                   #4  0x00007f6eea83b7d7 n/a (libnvidia-eglcore.so.580.105.08 + 0xa3b7d7)
                                                   #5  0x00007f6eea844851 n/a (libnvidia-eglcore.so.580.105.08 + 0xa44851)
                                                   #6  0x00007f6eea52c5b9 n/a (libnvidia-eglcore.so.580.105.08 + 0x72c5b9)
                                                   #7  0x00007f6f0550b7d6 _ZN4KWin14GLVertexBufferD2Ev (libkwin.so.6 + 0x30b7d6)
                                                   #8  0x00007f6f0550b973 _ZN4KWin16GLTexturePrivateD1Ev (libkwin.so.6 + 0x30b973)
                                                   #9  0x00007f6f0550ba6d _ZN4KWin9GLTextureD1Ev (libkwin.so.6 + 0x30ba6d)
                                                   #10 0x00007f6f0550bab3 _ZN4KWin9GLTextureD0Ev (libkwin.so.6 + 0x30bab3)
                                                   #11 0x0000561c60890542 n/a (/usr/bin/kwin_wayland + 0x10a542)
                                                   #12 0x00007f6f029d716f n/a (libQt6Core.so.6 + 0x1d716f)
                                                   #13 0x00007f6f029e439c _ZN6QTimer10timerEventEP11QTimerEvent (libQt6Core.so.6 + 0x1e439c)
                                                   #14 0x00007f6f029c44f6 _ZN7QObject5eventEP6QEvent (libQt6Core.so.6 + 0x1c44f6)
                                                   #15 0x00007f6f03b020a0 _ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent (libQt6Widgets.so.6 + 0x1020a0)
                                                   #16 0x00007f6f0296a6c8 _ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent (libQt6Core.so.6 + 0x16a6c8)
                                                   #17 0x00007f6f02b2c6af _ZN14QTimerInfoList14activateTimersEv (libQt6Core.so.6 + 0x32c6af)
                                                   #18 0x00007f6f02b2f901 _ZN20QEventDispatcherUNIX13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Core.so.6 + 0x32f901)
                                                   #19 0x00007f6f03734773 _ZN23QUnixEventDispatcherQPA13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt6Gui.so.6 + 0x734773)
                                                   #20 0x00007f6f02975a86 _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt6Core.so.6 + 0x175a86)
                                                   #21 0x00007f6f0296f171 _ZN16QCoreApplication4execEv (libQt6Core.so.6 + 0x16f171)
                                                   #22 0x0000561c607c2a80 n/a (/usr/bin/kwin_wayland + 0x3ca80)
                                                   #23 0x00007f6f02027b8b n/a (libc.so.6 + 0x27b8b)
                                                   #24 0x00007f6f02027c4b __libc_start_main (libc.so.6 + 0x27c4b)
                                                   #25 0x0000561c607ca2f5 n/a (/usr/bin/kwin_wayland + 0x442f5)

                                                   Stack trace of thread 1351:
                                                   #0  0x00007f6f020b0872 n/a (libc.so.6 + 0xb0872)
                                                   #1  0x00007f6f020a4248 n/a (libc.so.6 + 0xa4248)
                                                   #2  0x00007f6f020a49a3 n/a (libc.so.6 + 0xa49a3)
                                                   #3  0x00007f6f020a7773 pthread_cond_timedwait (libc.so.6 + 0xa7773)
                                                   #4  0x00007f6f02b351c5 _ZN14QWaitCondition4waitEP6QMutex14QDeadlineTimer (libQt6Core.so.6 + 0x3351c5)
                                                   #5  0x00007f6f02a906fa n/a (libQt6Core.so.6 + 0x2906fa)
                                                   #6  0x00007f6f02b30ca9 n/a (libQt6Core.so.6 + 0x330ca9)
                                                   #7  0x00007f6f020a80d6 n/a (libc.so.6 + 0xa80d6)
                                                   #8  0x00007f6f0213b01c n/a (libc.so.6 + 0x13b01c)

Comment 2 TraceyC 2025-11-13 02:14:25 UTC

Thanks for the bug report and the backtraces. The backtraces are different, so there are two unrelated crashes.

The first one does look to be within kwin, I'll let the kwin developers have a look.

The second backtrace indicates a different crash. That backtrace indicates that the problem is in the proprietary NVIDIA drivers.
Please report this second issue to the NVIDIA folks, either by sending an email to linux-bugs@nvidia.com or making a post at https://forums.developer.nvidia.com/c/gpu-graphics/linux. It would be helpful to the NVIDIA developers if you could run nvidia-bug-report.sh and attach the resulting file in your report. Thanks!

Comment 3 TraceyC 2025-11-20 22:11:40 UTC

*** Bug 512403 has been marked as a duplicate of this bug. ***