Intermittent segfaults and application crashes on keyboard shortcut use

I’ve put this under KDE Plasma because it’s handling global shortcuts, but it’s not clear where the problem is.

I’m getting intermittent software crashes (mostly with associated segfaults) after using keyboard shortcuts (eg Ctrl+V to paste, or Ctrl+A to select all).

It makes no difference what software I’m working with - so far it’s happened on Qgis, Kate, Okular, Digikam and Firefox. The Firefox one has only happened once (I say this because it’s the only non-Qt application in the list, so this could still be Qt-related and that last merely a coincidence).

Most times journalctl reports a segfault, but the error code, process and CPU core changes each time (so far I’ve had the actual application eg Kate as the process, but in other cases it’s been reported as, so it doesn’t seem to be related to the actual process.

An example of the latest entry on crash (but these vary, as I said, quite a lot)

Apr 04 11:03:44 desk systemd-coredump[10803]: [🡕] Process 3387 (kate) of user 1000 dumped core.
                                              Stack trace of thread 3387:
                                              #0  0x0000000200000001 n/a (n/a + 0x0)
                                              ELF object binary architecture: AMD x86-64
Apr 04 11:03:43 desk systemd[1]: Started Process Core Dump (PID 10802/UID 0).
Apr 04 11:03:43 desk kernel: Code: Unable to access opcode bytes at 0x1ffffffd7.
Apr 04 11:03:43 desk kernel: kate[3387]: segfault at 200000001 ip 0000000200000001 sp 00007ffc5c4ef958 error 14 in kate[559f8681b000+7000] likely on CPU 8 (core 2, socket 0)

Another example

Apr 02 18:04:27 desk systemd-coredump[31713]: [🡕] Process 28987 (kate) of user 1000 dumped core.
                                              Stack trace of thread 28987:
                                              #0  0x00007f72d43f6130 n/a ( + 0x7f130)
                                              ELF object binary architecture: AMD x86-64
Apr 02 18:04:26 desk kernel: kate[28987]: segfault at 7f72d43f6130 ip 00007f72d43f6130 sp 00007ffcb6346798 error 15 in[7f72d43f4000+5000] likely on CPU 9 (core 3, socket 0)

This started after I made some adjustments to the keyboard shortcuts, but it’s happening on the use of keys I haven’t even adjusted (also I’ve changed all keys back to defaults in my first attempt to diagnose the problem).