[$] An Ubuntu kernel bug causes container crashes

Some system administrators running Ubuntu 20.04 had a rough time on
June 8, when Ubuntu published kernel packages containing a particularly
nasty bug that was caused by an Ubuntu-specific
patch to the kernel. The bug led to a kernel panic whenever a Docker container
was started. Fixed packages were made available on June 10, but there
are questions about what went wrong
with handling the patch; in particular, it is surprising that kernel 5.13,
which has been beyond its end-of-life
for months, made it onto machines running Ubuntu 20.04, which is supposed
to be a long-term support release.