You will all love this! I just reported a checksum failure downloading
an devuan iso file. Just before closing for the night, I checked
dmesg. And guess what: I was doing this on debian and it looks like
a kernel bug (it doesn't say panic) involving systemd-udev!!

:---------------------
11238.037689] INFO: task systemd-udevd:346 blocked for more than 120 seconds.
[11238.037692]       Not tainted 4.16.0-2-amd64 #1 Debian 4.16.16-2
[11238.037693] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[11238.037695] systemd-udevd   D    0   346      1 0x00000104
[11238.037698] Call Trace:
[11238.037710]  ? __schedule+0x291/0x870
[11238.037714]  schedule+0x28/0x80
[11238.037718]  schedule_preempt_disabled+0xa/0x10
[11238.037721]  __mutex_lock.isra.1+0x1a0/0x4e0
[11238.037726]  ? __blkdev_get+0x78/0x510
[11238.037728]  __blkdev_get+0x78/0x510
[11238.037735]  ? kmem_cache_alloc_trace+0x107/0x1b0
[11238.037738]  blkdev_get+0x12a/0x330
[11238.037741]  ? bd_acquire+0xd0/0xd0
----------------[snip] -------------------------

ael