[3.16.y-ckt stable] Patch "rtnetlink: call ->dellink on failure when ->newlink exists" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Thu Mar 19 10:11:18 UTC 2015


This is a note to let you know that I have just added a patch titled

    rtnetlink: call ->dellink on failure when ->newlink exists

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt9.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 4681bfc95688ba8d49c4f7a3da4c2bf81ac18105 Mon Sep 17 00:00:00 2001
From: WANG Cong <xiyou.wangcong at gmail.com>
Date: Fri, 13 Feb 2015 13:56:53 -0800
Subject: 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 <ignacy.gawedzki at green-communications.fr>
Signed-off-by: Cong Wang <xiyou.wangcong at gmail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
[ luis: backported to 3.16: based on davem's backport to 3.14 ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 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 888136a75454..b1e79ca03fa0 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;




More information about the kernel-team mailing list