[PATCH 4.3 01/55] Revert "vrf: fix double free and memory corruption on register_netdevice failure"

[Greg Kroah-Hartman]

4.3-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ben Hutchings <b...@decadent.org.uk>

This reverts commit b3abad339f8e268bb261e5844ab68b18a7797c29, which
was an attempt to backport commit 7f109f7cc37108cba7243bc832988525b0d85909
upstream.  The backport introduced a deadlock and other bugs.

Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
Acked-by: David S. Miller <da...@davemloft.net>
Acked-by: David Ahern <d...@cumulusnetworks.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/net/vrf.c |   15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -581,6 +581,7 @@ static int vrf_newlink(struct net *src_n
 {
        struct net_vrf *vrf = netdev_priv(dev);
        struct net_vrf_dev *vrf_ptr;
+       int err;
 
        if (!data || !data[IFLA_VRF_TABLE])
                return -EINVAL;
@@ -589,16 +590,26 @@ static int vrf_newlink(struct net *src_n
 
        dev->priv_flags |= IFF_VRF_MASTER;
 
+       err = -ENOMEM;
        vrf_ptr = kmalloc(sizeof(*dev->vrf_ptr), GFP_KERNEL);
        if (!vrf_ptr)
-               return -ENOMEM;
+               goto out_fail;
 
        vrf_ptr->ifindex = dev->ifindex;
        vrf_ptr->tb_id = vrf->tb_id;
 
+       err = register_netdevice(dev);
+       if (err < 0)
+               goto out_fail;
+
        rcu_assign_pointer(dev->vrf_ptr, vrf_ptr);
 
-       return register_netdev(dev);
+       return 0;
+
+out_fail:
+       kfree(vrf_ptr);
+       free_netdev(dev);
+       return err;
 }
 
 static size_t vrf_nl_getsize(const struct net_device *dev)