If a device is renamed and the original name is subsequently reused
for a new device, the following warning is generated:
sysctl duplicate entry: /net/mpls/conf/veth0//input
CPU: 3 PID: 1379 Comm: ip Not tainted 4.1.0-rc4+ #20
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
0000000000000000 0000000000000000 ffffffff81566aaf 0000000000000000
ffffffff81236279 ffff88002f7d7f00 0000000000000000 ffff88000db336d8
ffff88000db33698 0000000000000005 ffff88002e046000 ffff8800168c9280
Call Trace:
[<ffffffff81566aaf>] ? dump_stack+0x40/0x50
[<ffffffff81236279>] ? __register_sysctl_table+0x289/0x5a0
[<ffffffffa051a24f>] ? mpls_dev_notify+0x1ff/0x300 [mpls_router]
[<ffffffff8108db7f>] ? notifier_call_chain+0x4f/0x70
[<ffffffff81470e72>] ? register_netdevice+0x2b2/0x480
[<ffffffffa0524748>] ? veth_newlink+0x178/0x2d3 [veth]
[<ffffffff8147f84c>] ? rtnl_newlink+0x73c/0x8e0
[<ffffffff8147f27a>] ? rtnl_newlink+0x16a/0x8e0
[<ffffffff81459ff2>] ? __kmalloc_reserve.isra.30+0x32/0x90
[<ffffffff8147ccfd>] ? rtnetlink_rcv_msg+0x8d/0x250
[<ffffffff8145b027>] ? __alloc_skb+0x47/0x1f0
[<ffffffff8149badb>] ? __netlink_lookup+0xab/0xe0
[<ffffffff8147cc70>] ? rtnetlink_rcv+0x30/0x30
[<ffffffff8149e7a0>] ? netlink_rcv_skb+0xb0/0xd0
[<ffffffff8147cc64>] ? rtnetlink_rcv+0x24/0x30
[<ffffffff8149df17>] ? netlink_unicast+0x107/0x1a0
[<ffffffff8149e4be>] ? netlink_sendmsg+0x50e/0x630
[<ffffffff8145209c>] ? sock_sendmsg+0x3c/0x50
[<ffffffff81452beb>] ? ___sys_sendmsg+0x27b/0x290
[<ffffffff811bd258>] ? mem_cgroup_try_charge+0x88/0x110
[<ffffffff811bd5b6>] ? mem_cgroup_commit_charge+0x56/0xa0
[<ffffffff811d7700>] ? do_filp_open+0x30/0xa0
[<ffffffff8145336e>] ? __sys_sendmsg+0x3e/0x80
[<ffffffff8156c3f2>] ? system_call_fastpath+0x16/0x75
Fix this by unregistering the previous sysctl table (registered for
the path containing the original device name) and re-registering the
table for the path containing the new device name.
Fixes: 37bde79979 ("mpls: Per-device enabling of packet input")
Reported-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
0fae3bf018