From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Serge Hallyn <serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
Cc: Aristeu Rozanski <aris-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>,
"Serge E. Hallyn"
<serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org>,
containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH 1/2] device_cgroup: fix RCU usage
Date: Tue, 6 Nov 2012 12:29:17 -0800 [thread overview]
Message-ID: <20121106202917.GT30069@mtj.dyndns.org> (raw)
In-Reply-To: <20121106174841.GB28916@sergelap>
On Tue, Nov 06, 2012 at 11:48:41AM -0600, Serge Hallyn wrote:
> Quoting Tejun Heo (tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org):
> > dev_cgroup->exceptions is protected with devcgroup_mutex for writes
> > and RCU for reads; however, RCU usage isn't correct.
> >
> > * dev_exception_clean() doesn't use RCU variant of list_del() and
> > kfree(). The function can race with may_access() and may_access()
> > may end up dereferencing already freed memory. Use list_del_rcu()
> > and kfree_rcu() instead.
> >
> > * may_access() may be called only with RCU read locked but doesn't use
> > RCU safe traversal over ->exceptions. Use list_for_each_entry_rcu().
> >
> > Signed-off-by: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> > Cc: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> > Cc: Aristeu Rozanski <aris-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> > Cc: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
> > Cc: Serge E. Hallyn <serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org>
>
> Acked-by: Serge E. Hallyn <serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org>
Thanks, applied to cgroup/for-3.7-fixes.
--
tejun
next prev parent reply other threads:[~2012-11-06 20:29 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-06 17:16 [PATCH 1/2] device_cgroup: add lockdep asserts Tejun Heo
[not found] ` <20121106171612.GH30069-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2012-11-06 17:16 ` [PATCH 2/2] " Tejun Heo
2012-11-06 17:17 ` [PATCH 1/2] device_cgroup: fix RCU usage Tejun Heo
[not found] ` <20121106171737.GJ30069-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2012-11-06 17:48 ` Serge Hallyn
2012-11-06 20:29 ` Tejun Heo [this message]
2012-11-06 17:40 ` [PATCH 1/2] device_cgroup: add lockdep asserts Serge Hallyn
2012-11-06 20:29 ` Tejun Heo
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