Bug#985197: kwin-wayland: Drag and drop a file in Dolphin makes KDE Plasma Wayland crash

[Silvério Santos]

Package: kwin-wayland
Version: 4:5.20.5-1
Severity: important

Dear Maintainer,

Since the update to KDE Plasma 5.20 Dolphin makes the whole session crash,
displaying the login screen instead of completing the following process:
1. Grab a .ly file
2. Drag it to a subfolder
3. Before reaching the subfolder, the session is closed and the SDDM login
screen is displayed. This also happens when trying to drag outside of the file
list to avoid hovering over other files and sometimes when dragging the file
over a file information popup.

Feb 22 19:06:34 systemname kernel: kwin_wayland[12033]: segfault at e8 ip
00007fbbe21d5268 sp 00007ffe4b5000b0 error 4 in
libKWaylandServer.so.5.20.5[7fbbe217d000+b6000]
Feb 22 19:06:34 systemname kernel: Code: 00 00 48 8b 47 10 48 8b 40 48 c3 90 66
0f 1f 44 00 00 41 57 41 56 41 55 41 54 41 89 f4 55 48 89 fd 53 48 83 ec 18 4c
8b 7f 10 <49> 8b 87 c8 00 00 00 8b 48 0c 8b 58 08 89 4c 24 0c 89 5c 24 08 39
Feb 22 19:06:34 systemname org.kde.ActivityManager[12179]: The Wayland
connection broke. Did the Wayland compositor die?
Feb 22 19:06:34 systemname org.kde.ActivityManager[12179]: QSocketNotifier:
Invalid socket 6 and type 'Read', disabling...
Feb 22 19:06:34 systemname org.kde.ActivityManager[12179]: KCrash: crashing...
crashRecursionCounter = 2
Feb 22 19:06:34 systemname org.kde.ActivityManager[12179]: KCrash: Application
Name = kactivitymanagerd path = /usr/lib/x86_64-linux-gnu/libexec pid = 12179
Feb 22 19:06:34 systemname org.kde.ActivityManager[12179]: KCrash: Arguments:
/usr/lib/x86_64-linux-gnu/libexec/kactivitymanagerd
Feb 22 19:06:34 systemname org.kde.ActivityManager[12179]: KCrash: Attempting
to start /usr/lib/x86_64-linux-gnu/libexec/drkonqi
Feb 22 19:06:34 systemname pulseaudio[12137]: X connection to :1 broken
(explicit kill or server shutdown).

-- System Information:
Debian Release: bullseye/sid
APT prefers testing-security
APT policy: (500, 'testing-security'), (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.10.0-4-amd64 (SMP w/4 CPU threads)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE=de
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages kwin-wayland depends on:
ii kwayland-integration 5.20.5-1
ii kwin-common 4:5.20.5-1
ii kwin-wayland-backend-drm 4:5.20.5-1
ii kwin-wayland-backend-wayland 4:5.20.5-1
ii kwin-wayland-backend-x11 4:5.20.5-1
ii libc6 2.31-9
ii libcap2 1:2.44-1
ii libcap2-bin 1:2.44-1
ii libepoxy0 1.5.5-1
ii libfontconfig1 2.13.1-4.2
ii libfreetype6 2.10.4+dfsg-1
ii libkf5coreaddons5 5.78.0-4
ii libkf5crash5 5.78.0-3
ii libkf5i18n5 5.78.0-2
ii libkf5idletime5 5.78.0-2
ii libkf5notifications5 5.78.0-2
ii libkf5quickaddons5 5.78.0-2
ii libkf5waylandclient5 4:5.78.0-2
ii libkf5windowsystem5 5.78.0-2
ii libkwaylandserver5 [libkwaylandserver5-5.20] 5.20.5-1
ii libkwineffects12a 4:5.20.5-1
ii libkwinglutils12 4:5.20.5-1
ii libpipewire-0.3-0 0.3.19-4
ii libqt5core5a [qtbase-abi-5-15-2] 5.15.2+dfsg-5
ii libqt5dbus5 5.15.2+dfsg-5
ii libqt5gui5 5.15.2+dfsg-5
ii libqt5widgets5 5.15.2+dfsg-5
ii libstdc++6 10.2.1-6
ii libxcb-xfixes0 1.14-3
ii libxcb1 1.14-3
ii xwayland 2:1.20.10-3

kwin-wayland recommends no packages.

kwin-wayland suggests no packages.

[Bernhard Übelacker]

Hello Santos,
I tried to reproduce this issue but did not see it inside a minimal VM.
Therefore tried to some more information from the Code bytes printed in
you journal/dmesg.

This should point to this instruction:
0x00007f6e16bd5268 <_ZN14KWaylandServer16SurfaceInterface13frameRenderedEj+24>: 49 8b 87 c8 00 00 00 mov 0xc8(%r15),%rax
A breakpoint set to this instruction points to this source line:
0x...268 in QListData::isEmpty() const at /usr/include/x86_64-linux-gnu/qt5/QtCore/qlist.h:116

The unmangled function name should read like this:
KWaylandServer::SurfaceInterface::frameRendered(unsigned int)


Unfortunately this seems not exact enough to take further actions.
Therefore I would suggest installing, if possible, the package
systemd-coredump. That way in the journal a simple backtrace should
be printed which might give an idea which functions are involved.
(As there may crash multiple processes as the wayland server dies,
make sure to get the lines after this line:
"Process ... (kwin_wayland) of user ... dumped core"


On the other side a search in upstream bugtracker returned [1].
I could immediately reproduce that crash by dragging an icon
from the kickoff menu onto a opened konsole window, which crashed
in the exact same instruction, pointed to by the code bytes from
the bug submission. Therefore I guess chances are not too bad
this bug is related.

Kind regards,
Bernhard

[1] https://bugs.kde.org/show_bug.cgi?id=428399

[Bernhard Übelacker]

Hello Silvério,



Am 31.03.21 um 20:42 schrieb Silvério Santos:
> Hallo Bernhard,
>
> Here is it:
>
> Mär 31 20:11:25 systemname kernel: kwin_wayland[1834]: segfault at e8 ip 00007fe70ba08268 sp 00007ffc9bbf64d0 error 4 in libKWaylandServer.so.5.20.5[7fe70b9b0000+b6000]
> Mär 31 20:11:25 systemname kernel: Code: 00 00 48 8b 47 10 48 8b 40 48 c3 90 66 0f 1f 44 00 00 41 57 41 56 41 55 41 54 41 89 f4 55 48 89 fd 53 48 83 ec 18 4c 8b 7f 10 <49> 8b 87 c8 00 00 00 8b 48 0c 8b 58 08 89 4c 24 0c 89 5c 24 08 39
> Mär 31 20:11:25 systemname systemd[1]: Created slice system-systemd\x2dcoredump.slice.
> Mär 31 20:11:25 systemname systemd[1]: Started Process Core Dump (PID 3494/UID 0).

> Mär 31 20:12:04 systemname systemd-coredump[3495]: Process 1834 (kwin_wayland) of user 1000 dumped core.
>
> Stack trace of thread 1834:
> #0 0x00007fe70ba08268 n/a (n/a + 0x0)
> Mär 31 20:12:05 systemname systemd[1]:systemd-...@0-3494-0.service: Succeeded.



thanks for the quick response, but unfortunately this
is less informative as I expected it to be.

If you have the package gdb installed could you please
try following commands and forward the output:

coredumpctl gdb 1834
set pagination off
bt

(With 1834 or the last pid shown after kwin_wayland
from the latest crash.)

Kind regards,
Bernhard

[Silvério Santos]

coredumpctl gdb 1920
PID: 1920 (kwin_wayland)
UID: 1000 (myname)
GID: 1000 (myname)
Signal: 11 (SEGV)
Timestamp: Sun 2021-04-04 09:10:40 CEST (7min ago)
Command Line: /usr/bin/kwin_wayland --xwayland --exit-with-session=/usr/lib/
x86_64-linux-gnu/libexec/startplasma-waylandsession
Executable: /usr/bin/kwin_wayland
Control Group: /user.slice/user-1000.slice/session-3.scope
Unit: session-3.scope
Slice: user-1000.slice
Session: 3
Owner UID: 1000 (myname)
Boot ID: 0ae3171f524a465e9acb992a202f814b
Machine ID: f72ae64cabdcedd770963755524c666b
Hostname: systemname
Storage: /var/lib/systemd/coredump/core.kwin_wayland.
1000.0ae3171f524a465e9acb992a202f814b.1920.1617520240000000.zst (truncated)
Message: Process 1920 (kwin_wayland) of user 1000 dumped core.

Stack trace of thread 1920:
#0 0x00007f65188b9268 n/a (n/a + 0x0)

GNU gdb (Debian 10.1-1.7) 10.1.90.20210103-git
Copyright (C) 2021 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from /usr/bin/kwin_wayland...
(No debugging symbols found in /usr/bin/kwin_wayland)
BFD: warning: /tmp/user/1000/coredump-ySV5m6 is truncated: expected core file
size >= 2365169664, found: 2147483648

warning: Can't open file /memfd:wayland-cursor (deleted) during file-backed
mapping note processing

warning: Can't open file /memfd:wayland-shm (deleted) during file-backed mapping
note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file /tmp/#730 (deleted) during file-backed mapping note
processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file /tmp/#164 (deleted) during file-backed mapping note
processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file /run/user/1000/xwayland-shared-P4Yrw8 (deleted) during
file-backed mapping note processing

warning: Can't open file /run/user/1000/xwayland-shared-ioLr48 (deleted) during
file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file /memfd:JSGCHeap:QtQml (deleted) during file-backed
mapping note processing

warning: Can't open file /memfd:JSVMStack:QtQml (deleted) during file-backed
mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file /tmp/#110 (deleted) during file-backed mapping note
processing

warning: Can't open file /memfd:unknown-usage:QtQml (deleted) during file-backed
mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing
[New LWP 1920]
[New LWP 1921]
[New LWP 1922]
[New LWP 1923]
[New LWP 1929]
[New LWP 1926]
[New LWP 1924]
[New LWP 1925]
[New LWP 1927]
[New LWP 1932]
Cannot access memory at address 0x7f6518ff0088
Cannot access memory at address 0x7f6518ff0080
Failed to read a valid object file image from memory.
Core was generated by `/usr/bin/kwin_wayland --xwayland --exit-with-session=/
usr/lib/x86_64-linux-gnu/'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007f65188b9268 in ?? ()
[Current thread is 1 (LWP 1920)]
(gdb) set pagination off
(gdb) bt
#0 0x00007f65188b9268 in ?? ()
Backtrace stopped: Cannot access memory at address 0x7ffe4826c860

[Bernhard Übelacker]

Hello Silvério,

> Reading symbols from /usr/bin/kwin_wayland...
> (No debugging symbols found in /usr/bin/kwin_wayland)
> BFD: warning: /tmp/user/1000/coredump-ySV5m6 is truncated: expected core file
> size >= 2365169664, found: 2147483648

it looks like for some reason the kwin_wayland exceeds
the address space limit of systemd-coredump, therefore
the results are not good.


If you want to give it another try, then please uncomment
and raise this limit from e.g. 2GB to 3GB like this:

/etc/systemd/coredump.conf
...
ProcessSizeMax=3G
ExternalSizeMax=3G
...

systemctl daemon-reload


Then the size warning hopefully goes away on the next
attempt, and a better backtrace might be printed.

Kind regards,
Bernhard

[Silvério Santos]

coredumpctl gdb 1873
PID: 1873 (kwin_wayland)

UID: 1000 (myname)
GID: 1000 (myname)
Signal: 11 (SEGV)

Timestamp: Sat 2021-04-24 16:50:03 CEST (8min ago)

Command Line: /usr/bin/kwin_wayland --xwayland --exit-with-session=/usr/lib/
x86_64-linux-gnu/libexec/startplasma-waylandsession
Executable: /usr/bin/kwin_wayland
Control Group: /user.slice/user-1000.slice/session-3.scope
Unit: session-3.scope
Slice: user-1000.slice
Session: 3
Owner UID: 1000 (myname)

Boot ID: 3f5e361f45064a439039edb95549bbdf

Machine ID: f72ae64cabdcedd770963755524c666b
Hostname: systemname
Storage: /var/lib/systemd/coredump/core.kwin_wayland.

1000.3f5e361f45064a439039edb95549bbdf.1873.1619275803000000.zst
Message: Process 1873 (kwin_wayland) of user 1000 dumped core.

Stack trace of thread 1873:
#0 0x00007f4ffcc4b268
_ZN14KWaylandServer16SurfaceInterface13frameRenderedEj (libKWaylandServer.so.5
+ 0xd2268)
#1 0x00007f4ffd177cf0 n/a (libkwin.so.5 + 0x1aacf0)
#2 0x00007f4ffba09546 n/a (libQt5Core.so.5 + 0x2e4546)
#3 0x00007f4ffd0a1aa5 _ZN4KWin6Cursor8renderedERK5QRect
(libkwin.so.5 + 0xd4aa5)
#4 0x00007f4ffd0ec2c6
_ZN4KWin10Compositor18performCompositingEv (libkwin.so.5 + 0x11f2c6)
#5 0x00007f4ffb9feecf _ZN7QObject5eventEP6QEvent
(libQt5Core.so.5 + 0x2d9ecf)
#6 0x00007f4ffc49615f
_ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent (libQt5Widgets.so.5
+ 0x16315f)
#7 0x00007f4ffb9d2f6a
_ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent (libQt5Core.so.5 +
0x2adf6a)
#8 0x00007f4ffba29883 _ZN14QTimerInfoList14activateTimersEv
(libQt5Core.so.5 + 0x304883)
#9 0x00007f4ffba27d17
_ZN20QEventDispatcherUNIX13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE
(libQt5Core.so.5 + 0x302d17)
#10 0x00007f4ff588f06d n/a (KWinQpaPlugin.so + 0x4706d)
#11 0x00007f4ffb9d192b
_ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5 +
0x2ac92b)
#12 0x00007f4ffb9d9ba0 _ZN16QCoreApplication4execEv
(libQt5Core.so.5 + 0x2b4ba0)
#13 0x0000556ea63913ab n/a (kwin_wayland + 0x153ab)
#14 0x00007f4ffb25fd0a __libc_start_main (libc.so.6 + 0x26d0a)
#15 0x0000556ea6391bea _start (kwin_wayland + 0x15bea)

Stack trace of thread 1874:
#0 0x00007f4ffb32c3ff __poll (libc.so.6 + 0xf33ff)
#1 0x00007f4ff91700ae n/a (libglib-2.0.so.0 + 0x520ae)
#2 0x00007f4ff91701cf g_main_context_iteration
(libglib-2.0.so.0 + 0x521cf)
#3 0x00007f4ffba2a4bf
_ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE
(libQt5Core.so.5 + 0x3054bf)
#4 0x00007f4ffb9d192b
_ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5 +
0x2ac92b)
#5 0x00007f4ffb7f0a3e _ZN7QThread4execEv (libQt5Core.so.5 +
0xcba3e)
#6 0x00007f4ffcac0a27 n/a (libQt5DBus.so.5 + 0x18a27)
#7 0x00007f4ffb7f1b81 n/a (libQt5Core.so.5 + 0xccb81)
#8 0x00007f4ffcb5fea7 start_thread (libpthread.so.0 + 0x8ea7)
#9 0x00007f4ffb336def __clone (libc.so.6 + 0xfddef)

Stack trace of thread 1875:
#0 0x00007f4ffb32c3ff __poll (libc.so.6 + 0xf33ff)
#1 0x00007f4ff91700ae n/a (libglib-2.0.so.0 + 0x520ae)
#2 0x00007f4ff91701cf g_main_context_iteration
(libglib-2.0.so.0 + 0x521cf)
#3 0x00007f4ffba2a4bf
_ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE
(libQt5Core.so.5 + 0x3054bf)
#4 0x00007f4ffb9d192b
_ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5 +
0x2ac92b)
#5 0x00007f4ffb7f0a3e _ZN7QThread4execEv (libQt5Core.so.5 +
0xcba3e)
#6 0x00007f4ffb7f1b81 n/a (libQt5Core.so.5 + 0xccb81)
#7 0x00007f4ffcb5fea7 start_thread (libpthread.so.0 + 0x8ea7)
#8 0x00007f4ffb336def __clone (libc.so.6 + 0xfddef)

Stack trace of thread 1876:
#0 0x00007f4ffb32c3ff __poll (libc.so.6 + 0xf33ff)
#1 0x00007f4ff91700ae n/a (libglib-2.0.so.0 + 0x520ae)
#2 0x00007f4ff91701cf g_main_context_iteration
(libglib-2.0.so.0 + 0x521cf)
#3 0x00007f4ffba2a4bf
_ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE
(libQt5Core.so.5 + 0x3054bf)
#4 0x00007f4ffb9d192b
_ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5 +
0x2ac92b)
#5 0x00007f4ffb7f0a3e _ZN7QThread4execEv (libQt5Core.so.5 +
0xcba3e)
#6 0x00007f4ffb7f1b81 n/a (libQt5Core.so.5 + 0xccb81)
#7 0x00007f4ffcb5fea7 start_thread (libpthread.so.0 + 0x8ea7)
#8 0x00007f4ffb336def __clone (libc.so.6 + 0xfddef)

Stack trace of thread 1879:
#0 0x00007f4ffcb667b2 pthread_cond_wait@@GLIBC_2.3.2
(libpthread.so.0 + 0xf7b2)
#1 0x00007f4fed9163bb n/a (iris_dri.so + 0x4e63bb)
#2 0x00007f4fed915e87 n/a (iris_dri.so + 0x4e5e87)
#3 0x00007f4ffcb5fea7 start_thread (libpthread.so.0 + 0x8ea7)
#4 0x00007f4ffb336def __clone (libc.so.6 + 0xfddef)

Stack trace of thread 1878:
#0 0x00007f4ffcb667b2 pthread_cond_wait@@GLIBC_2.3.2
(libpthread.so.0 + 0xf7b2)
#1 0x00007f4fed9163bb n/a (iris_dri.so + 0x4e63bb)
#2 0x00007f4fed915e87 n/a (iris_dri.so + 0x4e5e87)
#3 0x00007f4ffcb5fea7 start_thread (libpthread.so.0 + 0x8ea7)
#4 0x00007f4ffb336def __clone (libc.so.6 + 0xfddef)

Stack trace of thread 1880:
#0 0x00007f4ffcb667b2 pthread_cond_wait@@GLIBC_2.3.2
(libpthread.so.0 + 0xf7b2)
#1 0x00007f4fed9163bb n/a (iris_dri.so + 0x4e63bb)
#2 0x00007f4fed915e87 n/a (iris_dri.so + 0x4e5e87)
#3 0x00007f4ffcb5fea7 start_thread (libpthread.so.0 + 0x8ea7)
#4 0x00007f4ffb336def __clone (libc.so.6 + 0xfddef)

Stack trace of thread 1885:
#0 0x00007f4ffcb667b2 pthread_cond_wait@@GLIBC_2.3.2
(libpthread.so.0 + 0xf7b2)
#1 0x00007f4ffb0278fc n/a (libQt5Script.so.5 + 0x1708fc)
#2 0x00007f4ffb027929 n/a (libQt5Script.so.5 + 0x170929)
#3 0x00007f4ffcb5fea7 start_thread (libpthread.so.0 + 0x8ea7)
#4 0x00007f4ffb336def __clone (libc.so.6 + 0xfddef)

Stack trace of thread 1877:
#0 0x00007f4ffcb667b2 pthread_cond_wait@@GLIBC_2.3.2
(libpthread.so.0 + 0xf7b2)
#1 0x00007f4fed9163bb n/a (iris_dri.so + 0x4e63bb)
#2 0x00007f4fed915e87 n/a (iris_dri.so + 0x4e5e87)
#3 0x00007f4ffcb5fea7 start_thread (libpthread.so.0 + 0x8ea7)
#4 0x00007f4ffb336def __clone (libc.so.6 + 0xfddef)

Stack trace of thread 1882:
#0 0x00007f4ffb32c3ff __poll (libc.so.6 + 0xf33ff)
#1 0x00007f4ff91700ae n/a (libglib-2.0.so.0 + 0x520ae)
#2 0x00007f4ff91701cf g_main_context_iteration
(libglib-2.0.so.0 + 0x521cf)
#3 0x00007f4ffba2a4bf
_ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE
(libQt5Core.so.5 + 0x3054bf)
#4 0x00007f4ffb9d192b
_ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5 +
0x2ac92b)
#5 0x00007f4ffb7f0a3e _ZN7QThread4execEv (libQt5Core.so.5 +
0xcba3e)
#6 0x00007f4ffa38ef85 n/a (libQt5Qml.so.5 + 0x307f85)
#7 0x00007f4ffb7f1b81 n/a (libQt5Core.so.5 + 0xccb81)
#8 0x00007f4ffcb5fea7 start_thread (libpthread.so.0 + 0x8ea7)
#9 0x00007f4ffb336def __clone (libc.so.6 + 0xfddef)

GNU gdb (Debian 10.1-1.7) 10.1.90.20210103-git
Copyright (C) 2021 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...

Reading symbols from /usr/bin/kwin_wayland...
(No debugging symbols found in /usr/bin/kwin_wayland)

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file /memfd:wayland-shm (deleted) during file-backed mapping
note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file /memfd:wayland-cursor (deleted) during file-backed
mapping note processing

warning: Can't open file /tmp/#300 (deleted) during file-backed mapping note

processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file /tmp/#194 (deleted) during file-backed mapping note

processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file /run/user/1000/xwayland-shared-LZbtzA (deleted) during
file-backed mapping note processing

warning: Can't open file /run/user/1000/xwayland-shared-anHUnA (deleted) during

file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file anon_inode:i915.gem which was expanded to
anon_inode:i915.gem during file-backed mapping note processing

warning: Can't open file /memfd:JSGCHeap:QtQml (deleted) during file-backed
mapping note processing

warning: Can't open file /memfd:JSVMStack:QtQml (deleted) during file-backed
mapping note processing

warning: Can't open file /tmp/#112 (deleted) during file-backed mapping note

[New LWP 1873]
[New LWP 1874]
[New LWP 1875]
[New LWP 1876]
[New LWP 1879]
[New LWP 1878]
[New LWP 1880]
[New LWP 1885]
[New LWP 1877]
[New LWP 1882]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Core was generated by `/usr/bin/kwin_wayland --xwayland --exit-with-session=/
usr/lib/x86_64-linux-gnu/'.
Program terminated with signal SIGSEGV, Segmentation fault.

#0 0x00007f4ffcc4b268 in
KWaylandServer::SurfaceInterface::frameRendered(unsigned int) ()
from /usr/lib/x86_64-linux-gnu/libKWaylandServer.so.5
[Current thread is 1 (Thread 0x7f4ff5b918c0 (LWP 1873))]

(gdb) set pagination off
(gdb) bt

#0 0x00007f4ffcc4b268 in
KWaylandServer::SurfaceInterface::frameRendered(unsigned int) () at /usr/lib/
x86_64-linux-gnu/libKWaylandServer.so.5
#1 0x00007f4ffd177cf0 in () at /usr/lib/x86_64-linux-gnu/libkwin.so.5
#2 0x00007f4ffba09546 in () at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#3 0x00007f4ffd0a1aa5 in KWin::Cursor::rendered(QRect const&) () at /usr/lib/
x86_64-linux-gnu/libkwin.so.5
#4 0x00007f4ffd0ec2c6 in KWin::Compositor::performCompositing() () at /usr/
lib/x86_64-linux-gnu/libkwin.so.5
#5 0x00007f4ffb9feecf in QObject::event(QEvent*) () at /usr/lib/x86_64-linux-
gnu/libQt5Core.so.5
#6 0x00007f4ffc49615f in QApplicationPrivate::notify_helper(QObject*, QEvent*)
() at /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#7 0x00007f4ffb9d2f6a in QCoreApplication::notifyInternal2(QObject*, QEvent*)
() at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8 0x00007f4ffba29883 in QTimerInfoList::activateTimers() () at /usr/lib/
x86_64-linux-gnu/libQt5Core.so.5
#9 0x00007f4ffba27d17 in
QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
at /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#10 0x00007f4ff588f06d in () at /usr/lib/x86_64-linux-gnu/qt5/plugins/
platforms/KWinQpaPlugin.so
#11 0x00007f4ffb9d192b in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/x86_64-
linux-gnu/libQt5Core.so.5
#12 0x00007f4ffb9d9ba0 in QCoreApplication::exec() () at /usr/lib/x86_64-linux-
gnu/libQt5Core.so.5
#13 0x0000556ea63913ab in ()
#14 0x00007f4ffb25fd0a in __libc_start_main () at /lib/x86_64-linux-gnu/
libc.so.6
#15 0x0000556ea6391bea in _start ()
(gdb)

[Silvério Santos]

In Dolphin: menu Settings/Configure Dolphin/General, Behavior: Show short info
Disabling this option stops the crashes.