Tejun writes:
"cgroup fixes for v4.19-rc7
One cgroup2 threaded mode fix for v4.19-rc7. While threaded mode
isn't used widely (yet) and the bug requires somewhat convoluted
sequence of operations, it causes a userland visible malfunction -
EINVAL on a valid attempt to enable threaded mode. This pull request
contains the fix"
* 'for-4.19-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: Fix dom_cgrp propagation when enabling threaded mode