bridge: flush br's address entry in fdb when remove the

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=f873042093c0b418d2351fe142222b625c740149
Commit:     f873042093c0b418d2351fe142222b625c740149
Parent:     d2615bf450694c1302d86b9cc8a8958edfe4c3a4
Author:     Ding Tianhong <dingtianhong at huawei.com>
AuthorDate: Sat Dec 7 22:12:05 2013 +0800
Committer:  David S. Miller <davem at davemloft.net>
CommitDate: Wed Nov 20 15:31:11 2013 -0500

    bridge: flush br's address entry in fdb when remove the
    
     bridge dev
    
    When the following commands are executed:
    
    brctl addbr br0
    ifconfig br0 hw ether <addr>
    rmmod bridge
    
    The calltrace will occur:
    
    [  563.312114] device eth1 left promiscuous mode
    [  563.312188] br0: port 1(eth1) entered disabled state
    [  563.468190] kmem_cache_destroy bridge_fdb_cache: Slab cache still has objects
    [  563.468197] CPU: 6 PID: 6982 Comm: rmmod Tainted: G           O 3.12.0-0.7-default+ #9
    [  563.468199] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
    [  563.468200]  0000000000000880 ffff88010f111e98 ffffffff814d1c92 ffff88010f111eb8
    [  563.468204]  ffffffff81148efd ffff88010f111eb8 0000000000000000 ffff88010f111ec8
    [  563.468206]  ffffffffa062a270 ffff88010f111ed8 ffffffffa063ac76 ffff88010f111f78
    [  563.468209] Call Trace:
    [  563.468218]  [<ffffffff814d1c92>] dump_stack+0x6a/0x78
    [  563.468234]  [<ffffffff81148efd>] kmem_cache_destroy+0xfd/0x100
    [  563.468242]  [<ffffffffa062a270>] br_fdb_fini+0x10/0x20 [bridge]
    [  563.468247]  [<ffffffffa063ac76>] br_deinit+0x4e/0x50 [bridge]
    [  563.468254]  [<ffffffff810c7dc9>] SyS_delete_module+0x199/0x2b0
    [  563.468259]  [<ffffffff814e0922>] system_call_fastpath+0x16/0x1b
    [  570.377958] Bridge firewalling registered
    
    --------------------------- cut here -------------------------------
    
    The reason is that when the bridge dev's address is changed, the
    br_fdb_change_mac_address() will add new address in fdb, but when
    the bridge was removed, the address entry in the fdb did not free,
    the bridge_fdb_cache still has objects when destroy the cache, Fix
    this by flushing the bridge address entry when removing the bridge.
    
    v2: according to the Toshiaki Makita and Vlad's suggestion, I only
        delete the vlan0 entry, it still have a leak here if the vlan id
        is other number, so I need to call fdb_delete_by_port(br, NULL, 1)
        to flush all entries whose dst is NULL for the bridge.
    
    Suggested-by: Toshiaki Makita <toshiaki.makita1 at gmail.com>
    Suggested-by: Vlad Yasevich <vyasevich at gmail.com>
    Signed-off-by: Ding Tianhong <dingtianhong at huawei.com>
    Signed-off-by: David S. Miller <davem at davemloft.net>
---
 net/bridge/br_if.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 6e6194f..4bf02ad 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -172,6 +172,8 @@ void br_dev_delete(struct net_device *dev, struct list_head *head)
 		del_nbp(p);
 	}
 
+	br_fdb_delete_by_port(br, NULL, 1);
+
 	br_vlan_flush(br);
 	del_timer_sync(&br->gc_timer);