From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>,
Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Calvin Owens <calvinowens-b10kYP2dOMg@public.gmane.org>,
kernel-team-b10kYP2dOMg@public.gmane.org
Subject: Re: [PATCH cgroup/for-4.4] cgroup: fix race condition around termination check in css_task_iter_next()
Date: Thu, 29 Oct 2015 12:02:17 +0900 [thread overview]
Message-ID: <20151029030217.GC27115@mtj.duckdns.org> (raw)
In-Reply-To: <20151027084504.GB8783-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org>
On Tue, Oct 27, 2015 at 05:45:04PM +0900, Tejun Heo wrote:
> css_task_iter_next() checked @it->cur_task before grabbing
> css_set_lock and assumed that the result won't change afterwards;
> however, tasks could leave the cgroup being iterated terminating the
> iterator before css_task_lock is acquired. If this happens,
> css_task_iter_next() tries to calculate the current task from NULL
> cg_list pointer leading to the following oops.
Applied to cgroup/for-4.4. Thanks.
--
tejun
prev parent reply other threads:[~2015-10-29 3:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-27 8:45 [PATCH cgroup/for-4.4] cgroup: fix race condition around termination check in css_task_iter_next() Tejun Heo
[not found] ` <20151027084504.GB8783-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org>
2015-10-29 1:53 ` Zefan Li
2015-10-29 3:02 ` Tejun Heo [this message]
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