Re: [PATCH] mm,page_alloc: PF_WQ_WORKER threads must sleep at should_reclaim_retry().

[Tetsuo Handa]

On 2018/07/31 4:10, Michal Hocko wrote:
> Since should_reclaim_retry() should be a natural reschedule point,
> let's do the short sleep for PF_WQ_WORKER threads unconditionally in
> order to guarantee that other pending work items are started. This will
> workaround this problem and it is less fragile than hunting down when
> the sleep is missed. E.g. we used to have a sleeping point in the oom
> path but this has been removed recently because it caused other issues.
> Having a single sleeping point is more robust.

linux.git has not removed the sleeping point in the OOM path yet. Since removing the
sleeping point in the OOM path can mitigate CVE-2016-10723, please do so immediately.
(And that change will conflict with Roman's cgroup aware OOM killer patchset. But it
should be easy to rebase.)