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| author | Ido Schimmel <idosch@mellanox.com> | 2017-04-10 14:59:28 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-04-11 22:22:44 -0400 |
| commit | 5b8d5429daa05bebef6ffd3297df3b502cc6f184 (patch) | |
| tree | 78c0c74da30e3525566ef791dc9330872dba71ba /net/bridge/br_netlink.c | |
| parent | b6fe0440c63716e09cfc0d1484e3898a0f29d1d1 (diff) | |
| download | lwn-5b8d5429daa05bebef6ffd3297df3b502cc6f184.tar.gz lwn-5b8d5429daa05bebef6ffd3297df3b502cc6f184.zip | |
bridge: netlink: register netdevice before executing changelink
Peter reported a kernel oops when executing the following command:
$ ip link add name test type bridge vlan_default_pvid 1
[13634.939408] BUG: unable to handle kernel NULL pointer dereference at
0000000000000190
[13634.939436] IP: __vlan_add+0x73/0x5f0
[...]
[13634.939783] Call Trace:
[13634.939791] ? pcpu_next_unpop+0x3b/0x50
[13634.939801] ? pcpu_alloc+0x3d2/0x680
[13634.939810] ? br_vlan_add+0x135/0x1b0
[13634.939820] ? __br_vlan_set_default_pvid.part.28+0x204/0x2b0
[13634.939834] ? br_changelink+0x120/0x4e0
[13634.939844] ? br_dev_newlink+0x50/0x70
[13634.939854] ? rtnl_newlink+0x5f5/0x8a0
[13634.939864] ? rtnl_newlink+0x176/0x8a0
[13634.939874] ? mem_cgroup_commit_charge+0x7c/0x4e0
[13634.939886] ? rtnetlink_rcv_msg+0xe1/0x220
[13634.939896] ? lookup_fast+0x52/0x370
[13634.939905] ? rtnl_newlink+0x8a0/0x8a0
[13634.939915] ? netlink_rcv_skb+0xa1/0xc0
[13634.939925] ? rtnetlink_rcv+0x24/0x30
[13634.939934] ? netlink_unicast+0x177/0x220
[13634.939944] ? netlink_sendmsg+0x2fe/0x3b0
[13634.939954] ? _copy_from_user+0x39/0x40
[13634.939964] ? sock_sendmsg+0x30/0x40
[13634.940159] ? ___sys_sendmsg+0x29d/0x2b0
[13634.940326] ? __alloc_pages_nodemask+0xdf/0x230
[13634.940478] ? mem_cgroup_commit_charge+0x7c/0x4e0
[13634.940592] ? mem_cgroup_try_charge+0x76/0x1a0
[13634.940701] ? __handle_mm_fault+0xdb9/0x10b0
[13634.940809] ? __sys_sendmsg+0x51/0x90
[13634.940917] ? entry_SYSCALL_64_fastpath+0x1e/0xad
The problem is that the bridge's VLAN group is created after setting the
default PVID, when registering the netdevice and executing its
ndo_init().
Fix this by changing the order of both operations, so that
br_changelink() is only processed after the netdevice is registered,
when the VLAN group is already initialized.
Fixes: b6677449dff6 ("bridge: netlink: call br_changelink() during br_dev_newlink()")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Peter V. Saveliev <peter@svinota.eu>
Tested-by: Peter V. Saveliev <peter@svinota.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge/br_netlink.c')
| -rw-r--r-- | net/bridge/br_netlink.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c index a8f6acd23e30..225ef7d53701 100644 --- a/net/bridge/br_netlink.c +++ b/net/bridge/br_netlink.c @@ -1165,11 +1165,14 @@ static int br_dev_newlink(struct net *src_net, struct net_device *dev, spin_unlock_bh(&br->lock); } - err = br_changelink(dev, tb, data); + err = register_netdevice(dev); if (err) return err; - return register_netdevice(dev); + err = br_changelink(dev, tb, data); + if (err) + unregister_netdevice(dev); + return err; } static size_t br_get_size(const struct net_device *brdev) |