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From: Stephen Hemminger <shemminger@vyatta•com>
To: "Nicolas de Pesloüan" <nicolas.2p.debian@gmail•com>
Cc: David Miller <davem@davemloft•net>,
	Jay Vosburgh <fubar@us•ibm.com>,
	Andy Gospodarek <andy@greyhouse•net>,
	netdev@vger•kernel.org
Subject: Re: [PATCH] bonding: fix error handling if slave is busy (v2)
Date: Sat, 31 Dec 2011 16:13:22 -0800	[thread overview]
Message-ID: <20111231161322.40b16d69@nehalam.linuxnetplumber.net> (raw)
In-Reply-To: <4EFFA44E.10507@gmail.com>

On Sun, 01 Jan 2012 01:09:50 +0100
Nicolas de Pesloüan <nicolas.2p.debian@gmail•com> wrote:

> Le 01/01/2012 00:26, Stephen Hemminger a écrit :
> > If slave device already has a receive handler registered, then the
> > error unwind of bonding device enslave function is broken.
> >
> > The following will leave a pointer to freed memory in the slave
> > device list, causing a later kernel panic.
> > # modprobe dummy
> > # ip li add dummy0-1 link dummy0 type macvlan
> > # modprobe bonding
> > # echo +dummy0>/sys/class/net/bond0/bonding/slaves
> >
> > The fix is to detach the slave (which removes it from the list)
> > in the unwind path.
> >
> > Signed-off-by: Stephen Hemminger<shemminger@vyatta•com>
> 
> Thanks Stephen.
> 
> Reviewed-by: Nicolas de Pesloüan <nicolas.2p.debian@free•fr>

The locking in bond driver is a tangled web.

Would be cleaner to get rid of bond->lock altogether.
Slave add/delete should be protected by RTNL, and the lookup should
be converted to RCU.  The problem is that bonding driver implements
own form of circular list to handle round-robin etc.

  reply	other threads:[~2012-01-01  0:13 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-30 22:40 [PATCH] bonding: fix error handling if slave is busy Stephen Hemminger
2011-12-31 16:11 ` Nicolas de Pesloüan
2011-12-31 23:26   ` [PATCH] bonding: fix error handling if slave is busy (v2) Stephen Hemminger
2012-01-01  0:09     ` Nicolas de Pesloüan
2012-01-01  0:13       ` Stephen Hemminger [this message]
2012-01-01  0:28         ` Nicolas de Pesloüan
2012-01-03 17:49       ` David Miller

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