Message ID | 20220823050943.28619-1-Jing-Ting.Wu@mediatek.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | [1/1] cgroup: Fix race condition at rebind_subsystems() | expand |
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index ffaccd6373f1..0d0c959966ed 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -1820,6 +1820,7 @@ int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask) if (ss->css_rstat_flush) { list_del_rcu(&css->rstat_css_node); + synchronize_rcu(); list_add_rcu(&css->rstat_css_node, &dcgrp->rstat_css_list); }
Root cause: The rebind_subsystems() is no lock held when move css object from A list to B list,then let B's head be treated as css node at list_for_each_entry_rcu(). Solution: Add grace period before invalidating the removed rstat_css_node. Suggested-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Jing-Ting Wu <Jing-Ting.Wu@mediatek.com> --- kernel/cgroup/cgroup.c | 1 + 1 file changed, 1 insertion(+)