Messages in this thread Patch in this message | | | From | Jing-Ting Wu <> | Subject | [PATCH 1/1] cgroup: Fix race condition at rebind_subsystems() | Date | Tue, 23 Aug 2022 13:09:41 +0800 |
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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(+)
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); } -- 2.18.0
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