On Mon, Jun 10, 2019 at 09:16:19AM -0700, Tejun Heo wrote:
> Hello,
>
> Fix for another fallout. Applied to cgroup/for-5.2-fixes.
>
> Thanks.
>
> ------ 8< ------
> >From c596687a008b579c503afb7a64fcacc7270fae9e Mon Sep 17 00:00:00 2001
> From: Tejun Heo <tj@xxxxxxxxxx>
> Date: Mon, 10 Jun 2019 09:08:27 -0700
>
> While adding handling for dying task group leaders c03cd7738a83
> ("cgroup: Include dying leaders with live threads in PROCS
> iterations") added an inverted cset skip condition to
> css_task_iter_advance_css_set(). It should skip cset if it's
> completely empty but was incorrectly testing for the inverse condition
> for the dying_tasks list. Fix it.
>
> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
> Fixes: c03cd7738a83 ("cgroup: Include dying leaders with live threads in PROCS iterations")
> Reported-by: syzbot+d4bba5ccd4f9a2a68681@xxxxxxxxxxxxxxxxxxxxxxxxx
> ---
> kernel/cgroup/cgroup.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
> index 9538a12d42d6..6420ff87d72c 100644
> --- a/kernel/cgroup/cgroup.c
> +++ b/kernel/cgroup/cgroup.c
> @@ -4401,7 +4401,7 @@ static void css_task_iter_advance_css_set(struct css_task_iter *it)
> it->task_pos = NULL;
> return;
> }
> - } while (!css_set_populated(cset) && !list_empty(&cset->dying_tasks));
> + } while (!css_set_populated(cset) && list_empty(&cset->dying_tasks));
>
> if (!list_empty(&cset->tasks))
> it->task_pos = cset->tasks.next;
> --
> 2.17.1
>
These all made it into 5.2 now. Should they also be backported to 4.19
and/or any older stable kernels?
thanks,
greg k-h
