What were you trying to do that didn't work?

Stop a service managed by systemd. The service is stopped but systemd (pid 1) crashes (see attached logs) and enters frozen mode.

What is the impact of this issue to you?

systemd is unusable once frozen and the only recovery is a hard reboot with systemctl reboot --force --force

Please provide the package NVR for which the bug is seen:

systemd 252 (252-55.el9_7.2)
Linux 5.14.0-611.11.1.el9_7.x86_64 #1 SMP PREEMPT_DYNAMIC Tue Nov 25 05:13:22 EST 2025 x86_64 x86_64 x86_64 GNU/Linux

How reproducible is this bug?:

Easy to reproduce, for example stopping the smartd service as below.

Steps to reproduce

1. systemctl stop smartd  

Expected results

The smartd service is stopped and systemd continues to run as normal.

Actual results

The smartd service is stopped but systemd crashes.