From c9f412a4c739cb7eb2b6af845f97539d8d1fcf44 Mon Sep 17 00:00:00 2001 From: WANG Cong Date: Fri, 13 Feb 2015 13:56:53 -0800 Subject: [PATCH 1/1] rtnetlink: call ->dellink on failure when ->newlink exists [ 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 Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/core/rtnetlink.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 2c51dfbed5e6..5b412f0627c3 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1860,8 +1860,16 @@ replay: goto out; 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; -- 2.39.2