Re: [PATCH] mm/memcg: return value of the function mem_cgroup_from_css() is not checked

From: Yizhuo Zhai
Date: Fri Aug 30 2019 - 18:27:24 EST


Our tool did not trace back the whole path, so, now we could say it
might happen.

On Thu, Aug 22, 2019 at 1:12 PM Michal Hocko <mhocko@xxxxxxxxxx> wrote:
>
> On Thu 22-08-19 13:07:17, Yizhuo Zhai wrote:
> > This will happen if variable "wb->memcg_css" is NULL. This case is reported
> > by our analysis tool.
>
> Does your tool report the particular call path and conditions when that
> happen? Or is it just a "it mignt happen" kinda thing?
>
> > Since the function mem_cgroup_wb_domain() is visible to the global, we
> > cannot control caller's behavior.
>
> I am sorry but I do not understand what is this supposed to mean.
> --
> Michal Hocko
> SUSE Labs



--
Kind Regards,

Yizhuo Zhai

Computer Science, Graduate Student
University of California, Riverside