Re: [PATCH 1/1] cgroup: Fix race condition at rebind_subsystems()

From: Tejun Heo
Date: Tue Aug 23 2022 - 15:26:25 EST


On Tue, Aug 23, 2022 at 01:41:46PM +0800, Jing-Ting Wu wrote:
> 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.
>
> Reported-by: Jing-Ting Wu <jing-ting.wu@xxxxxxxxxxxx>
> Suggested-by: Michal Koutný <mkoutny@xxxxxxxx>
> Signed-off-by: Jing-Ting Wu <jing-ting.wu@xxxxxxxxxxxx>
> Tested-by: Jing-Ting Wu <jing-ting.wu@xxxxxxxxxxxx>
> Link: https://lore.kernel.org/linux-arm-kernel/d8f0bc5e2fb6ed259f9334c83279b4c011283c41.camel@xxxxxxxxxxxx/T/

Applied to cgroup/for-6.0-fixes w/ stable tag added.

Thanks.

--
tejun