From: Jens Axboe <axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
To: Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Joe Lawrence
<joe.lawrence-7+ureL1bLXNBDgjK7y7TUQ@public.gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Cgroups <cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH block/for-linus] blkcg: fix use-after-free in __blkg_release_rcu() by making blkcg_gq refcnt an atomic_t
Date: Fri, 20 Jun 2014 12:50:53 -0600 [thread overview]
Message-ID: <53A4828D.9000200@kernel.dk> (raw)
In-Reply-To: <20140620143901.GC7354-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
On 06/20/2014 08:39 AM, Vivek Goyal wrote:
> On Thu, Jun 19, 2014 at 05:42:57PM -0400, Tejun Heo wrote:
>> Hello,
>>
>> So, this patch should do. Joe, Vivek, can one of you guys please
>> verify that the oops goes away with this patch?
>
> Hi Tejun,
>
> This patch seems to fix the issue for me. Tried 10 times and no crash.
>
> So now one need to hold queue lock for getting refernce on the group
> only if caller does not already have a reference and if group has been
> looked up from some tree/queue etc. I guess only such usage seems to
> be in blkg_create() where we take a reference on parent after looking
> it up.
>
> This patch looks good to me.
>
> Acked-by: Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Thanks. Tejun, I'll queue this up for this cycle.
--
Jens Axboe
next prev parent reply other threads:[~2014-06-20 18:50 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <alpine.DEB.2.02.1406081816540.17948@jlaw-desktop.mno.stratus.com>
[not found] ` <20140609174708.GA31499@redhat.com>
[not found] ` <20140609182728.GB31499@redhat.com>
[not found] ` <20140610143906.0d2f35d0@jlaw-desktop.mno.stratus.com>
[not found] ` <20140610143906.0d2f35d0-ceYW5R1vr2hcrvxNGtJwk767FWEIOpWeVpNB7YpNyf8@public.gmane.org>
2014-06-11 16:32 ` docker crashes rcuos in __blkg_release_rcu Vivek Goyal
[not found] ` <20140611163229.GA12974-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-06-19 20:26 ` Tejun Heo
[not found] ` <20140619202640.GA9814-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2014-06-19 21:42 ` [PATCH block/for-linus] blkcg: fix use-after-free in __blkg_release_rcu() by making blkcg_gq refcnt an atomic_t Tejun Heo
[not found] ` <20140619214257.GE9814-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2014-06-20 14:39 ` Vivek Goyal
[not found] ` <20140620143901.GC7354-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-06-20 18:50 ` Jens Axboe [this message]
2014-06-20 18:50 ` Joe Lawrence
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