From: WANG Cong Date: Fri, 13 Feb 2015 21:56:53 +0000 (-0800) Subject: rtnetlink: call ->dellink on failure when ->newlink exists X-Git-Tag: v3.16.35~2633 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4681bfc95688ba8d49c4f7a3da4c2bf81ac18105;p=thirdparty%2Fkernel%2Fstable.git rtnetlink: call ->dellink on failure when ->newlink exists commit 7afb8886a05be68e376655539a064ec672de8a8e upstream. 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 Signed-off-by: Cong Wang Signed-off-by: David S. Miller [ luis: backported to 3.16: based on davem's backport to 3.14 ] Signed-off-by: Luis Henriques --- diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 888136a75454b..b1e79ca03fa01 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -2069,8 +2069,16 @@ 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;