I've checked the above crash of Cinnamon with the Virtual Keyboard on Linux Mint 20.1 (currently beta). That crash was reproducible there as well (even with Cinnamon 4.8.5) until I updated the system today. Don't know exactly how they fixed it.
Also the following SELinux alert appears after the crash:
SELinux is preventing gdb from read access on the chr_file card0.
* Plugin catchall (100. confidence) suggests ******
If you believe that gdb should be allowed read access on the card0 chr_file by default. Then you should report this as a bug. You can generate a local policy module to allow this access. Do allow this access for now by executing:
Additional Information:
Source Context system_u:system_r:abrt_t:s0-s0:c0.c1023
Target Context system_u:object_r:dri_device_t:s0
Target Objects card0 [ chr_file ]
Source gdb
Source Path gdb
Port <Unknown>
Host localhost.localdomain
Source RPM Packages
Target RPM Packages
SELinux Policy RPM selinux-policy-targeted-3.14.6-33.fc33.noarch
Local Policy RPM selinux-policy-targeted-3.14.6-33.fc33.noarch
Selinux Enabled True
Policy Type targeted
Enforcing Mode Enforcing
Host Name localhost.localdomain
Platform Linux localhost.localdomain 5.9.16-200.fc33.x86_64
#1 SMP Mon Dec 21 14:08:22 UTC 2020 x86_64 x86_64
Alert Count 1
First Seen 2020-12-30 22:39:55 IST
Last Seen 2020-12-30 22:39:55 IST
Local ID 0a902367-c169-487e-a338-f6ace1a63b6b
Raw Audit Messages type=AVC msg=audit(1609360795.782:528): avc: denied { read } for pid=1886 comm="gdb" name="card0" dev="devtmpfs" ino=355 scontext=system_u:system_r:abrt_t:s0-s0:c0.c1023 tcontext=system_u:object_r:dri_device_t:s0 tclass=chr_file permissive=0
Hash: gdb,abrt_t,dri_device_t,chr_file,read
Tested on another VM with Cinnamon 4.8.3 and it crashes after the above scenario as well.
Cinnamon always crashes in following scenario:
Virtual keyboard
application that opens a virtual keyboard in the top side of the screenVirtual keyboard
on your screen and then on some other button.After the second click Cinnamon crashes.
I didn't try such a scenario with the previous 4.8.3 update. Usually I don't use any virtual keyboard. I've got into this scenario by curiosity, after reading commits between 4.8.3 and 4.8.4. Maybe the following upstream commit relates to this bug: https://github.com/linuxmint/cinnamon/commit/41e609565643759d2abf6b769d3580877d898580
Could it also be update to 4.8.4?
Seems good
Dell Latitude 5480 Intel Core i7-7820HQ 32 GB of RAM