On IRC chat we identified an issue related to linux SAK, which is explained here https://www.kernel.org/doc/html/latest/security/sak.html Following the check what processes will be SAK'ed: ~# ls -l /proc/[0-9]*/fd/* | grep console lrwx------ 1 root root 64 Aug 24 21:22 /proc/1/fd/1 -> /dev/console lrwx------ 1 root root 64 Aug 24 21:22 /proc/1/fd/2 -> /dev/console l-wx------ 1 root root 64 Aug 24 21:22 /proc/578/fd/4 -> /dev/console lrwx------ 1 root root 64 Aug 24 21:22 /proc/593/fd/1 -> /dev/console lrwx------ 1 root root 64 Aug 24 21:22 /proc/593/fd/2 -> /dev/console lrwx------ 1 root root 64 Aug 24 20:03 /proc/705/fd/1 -> /dev/console lrwx------ 1 root root 64 Aug 24 20:03 /proc/705/fd/2 -> /dev/console lrwx------ 1 root root 64 Aug 24 21:22 /proc/909/fd/1 -> /dev/console lrwx------ 1 root root 64 Aug 24 21:22 /proc/909/fd/2 -> /dev/console As it is seen from above output, pid 1 which is shepherd holds /dev/console making linux SAK feature useless. When SAK command issued by shortcut keys, all above proceses gets killed including pid 1 which is shepherd, causing system to stall.