From: David Miller <davem@davemloft.net>
To: xiyou.wangcong@gmail.com
Cc: netdev@vger.kernel.org, Matt.Bennett@alliedtelesis.co.nz,
paulus@samba.org, linux-ppp@vger.kernel.org,
g.nault@alphalink.fr, gorcunov@openvz.org
Subject: Re: [Patch net] ppp: defer netns reference release for ppp channel
Date: Sat, 09 Jul 2016 03:47:54 +0000 [thread overview]
Message-ID: <20160708.234754.1545620882859351577.davem@davemloft.net> (raw)
In-Reply-To: <1467781956-2229-1-git-send-email-xiyou.wangcong@gmail.com>
From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Tue, 5 Jul 2016 22:12:36 -0700
> Matt reported that we have a NULL pointer dereference
> in ppp_pernet() from ppp_connect_channel(),
> i.e. pch->chan_net is NULL.
>
> This is due to that a parallel ppp_unregister_channel()
> could happen while we are in ppp_connect_channel(), during
> which pch->chan_net set to NULL. Since we need a reference
> to net per channel, it makes sense to sync the refcnt
> with the life time of the channel, therefore we should
> release this reference when we destroy it.
>
> Fixes: 1f461dcdd296 ("ppp: take reference on channels netns")
> Reported-by: Matt Bennett <Matt.Bennett@alliedtelesis.co.nz>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: linux-ppp@vger.kernel.org
> Cc: Guillaume Nault <g.nault@alphalink.fr>
> Cc: Cyrill Gorcunov <gorcunov@openvz.org>
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Applied and queued up for -stable.
prev parent reply other threads:[~2016-07-09 3:47 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-06 5:12 [Patch net] ppp: defer netns reference release for ppp channel Cong Wang
2016-07-06 8:26 ` Cyrill Gorcunov
2016-07-06 12:25 ` Cyrill Gorcunov
2016-07-28 10:33 ` Guillaume Nault
2016-07-31 22:22 ` Cyrill Gorcunov
2016-07-09 3:47 ` David Miller [this message]
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