WSL2-Linux-Kernel/kernel/cgroup
Tejun Heo d1897c9538 cgroup: fix rule checking for threaded mode switching
A domain cgroup isn't allowed to be turned threaded if its subtree is
populated or domain controllers are enabled.  cgroup_enable_threaded()
depended on cgroup_can_be_thread_root() test to enforce this rule.  A
parent which has populated domain descendants or have domain
controllers enabled can't become a thread root, so the above rules are
enforced automatically.

However, for the root cgroup which can host mixed domain and threaded
children, cgroup_can_be_thread_root() doesn't check any of those
conditions and thus first level cgroups ends up escaping those rules.

This patch fixes the bug by adding explicit checks for those rules in
cgroup_enable_threaded().

Reported-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 8cfd8147df ("cgroup: implement cgroup v2 thread support")
Cc: stable@vger.kernel.org # v4.14+
2018-02-21 11:39:22 -08:00
..
Makefile Merge branch 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2017-11-15 14:29:44 -08:00
cgroup-internal.h Merge branch 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2017-11-15 14:29:44 -08:00
cgroup-v1.c cgroup: Fix deadlock in cpu hotplug path 2017-12-19 05:38:47 -08:00
cgroup.c cgroup: fix rule checking for threaded mode switching 2018-02-21 11:39:22 -08:00
cpuset.c kernel/cpuset: current_cpuset_is_being_rebound can be boolean 2018-02-06 18:32:47 -08:00
debug.c debug cgroup: use task_css_set instead of rcu_dereference 2017-11-27 11:37:33 -08:00
freezer.c cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS 2017-07-21 11:14:51 -04:00
namespace.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pids.c cgroup: implement cgroup v2 thread support 2017-07-21 11:14:51 -04:00
rdma.c rdmacg: Fixed uninitialized current resource usage 2017-01-10 12:52:32 -05:00
stat.c cgroup: properly init u64_stats 2017-11-28 07:16:08 -08:00