Comment 14 for bug 2035406

The backtrace unfortunately doesn't provide any information that points to how this could be a systemd problem. The crashing thread appears to be:

Thread 12 (Thread 0x7f50a9f2e640 (LWP 282533) "ThreadPoolServi"):
#1 0x00007f50de277845 in buffered_vfprintf (s=0x7f50de41a6a0 <_IO_2_1_stderr_>, format=format@entry=0x7f50c74e8c85 "[%s] %s\n", args=args@entry=0x7f50a9f1c1e0, mode_flags=mode_flags@entry=2) at ./stdio-common/vfprintf-internal.c:2265
#2 0x00007f50de2766de in __vfprintf_internal (s=<optimized out>, format=0x7f50c74e8c85 "[%s] %s\n", ap=ap@entry=0x7f50a9f1c1e0, mode_flags=2) at ./stdio-common/vfprintf-internal.c:1236
#3 0x00007f50de334ec3 in ___fprintf_chk (fp=<optimized out>, flag=<optimized out>, format=<optimized out>) at ./debug/fprintf_chk.c:33
#4 0x00007f50c74cd37e in event_logv_ () at /lib/x86_64-linux-gnu/libevent-2.1.so.7
#5 0x00007f50c74cd549 in event_warn () at /lib/x86_64-linux-gnu/libevent-2.1.so.7
#6 0x00007f50c74d223c in () at /lib/x86_64-linux-gnu/libevent-2.1.so.7
#7 0x00007f50c74c95d1 in event_base_loop () at /lib/x86_64-linux-gnu/libevent-2.1.so.7
#8 0x00007f50d357c624 in () at /lib/x86_64-linux-gnu/libQt5WebEngineCore.so.5

since we don't see the format string arguments, this doesn't tell us what's being printed that's a problem or how it could be systemd-related.

I'm attaching the /lib/udev/rules.d/60-persistent-storage.rules from the previous version of systemd, 249.11-0ubuntu3.9. Since this is the only change in the new version affecting udev, even though we don't see how it would break your devices, we should test whether reverting this fixes your problem.

Please download the attached file and run the following commands:

sudo cp -a /lib/udev/rules.d/60-persistent-storage.rules{,.bak}
sudo mv 60-persistent-storage.rules /lib/udev/rules.d/60-persistent-storage.rules

Then reboot and report whether this has fixed your problem.

If it has not, we can walk you through a full manual rollback of the systemd package on your system.