| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.14 04/96] rtnetlink: call ->dellink on failure when ->newlink exists | Date | Mon, 16 Mar 2015 15:08:35 +0100 |
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3.14-stable review patch. If anyone has any objections, please let me know.
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From: WANG Cong <xiyou.wangcong@gmail.com>
[ Upstream commit 7afb8886a05be68e376655539a064ec672de8a8e ]
Ignacy reported that when eth0 is down and add a vlan device on top of it like:
ip link add link eth0 name eth0.1 up type vlan id 1
We will get a refcount leak:
unregister_netdevice: waiting for eth0.1 to become free. Usage count = 2
The problem is when rtnl_configure_link() fails in rtnl_newlink(), we simply call unregister_device(), but for stacked device like vlan, we almost do nothing when we unregister the upper device, more work is done when we unregister the lower device, so call its ->dellink().
Reported-by: Ignacy Gawedzki <ignacy.gawedzki@green-communications.fr> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/core/rtnetlink.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
--- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -2030,8 +2030,16 @@ replay: } } err = rtnl_configure_link(dev, ifm); - if (err < 0) - unregister_netdevice(dev); + if (err < 0) { + if (ops->newlink) { + LIST_HEAD(list_kill); + + ops->dellink(dev, &list_kill); + unregister_netdevice_many(&list_kill); + } else { + unregister_netdevice(dev); + } + } out: put_net(dest_net); return err;
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