Subject: [PATCH net-next-2.6] bonding: set device in RLB ARP packet handler

From: Jay Vosburgh <[email-masked]>
Date: Fri, 23 Jul 2010 13:02:04 -0700

From: Greg Edwards <[email-masked]>

After:

commit 6146b1a4da98377e4abddc91ba5856bef8f23f1e
Author: Jay Vosburgh <[email-masked]>
Date:   Tue Nov 4 17:51:15 2008 -0800

    bonding: Fix ALB mode to balance traffic on VLANs

the dev field in the RLB ARP packet handler was set to NULL to wildcard
and accommodate balancing VLANs on top of bonds.

This has the side-effect of the packet handler being called against
other, non RLB-enabled bonds, and a kernel oops results when it tries to
dereference rx_hashtbl in rlb_update_entry_from_arp(), which won't be
set for those bonds, e.g. active-backup.

With the __netif_receive_skb() changes from:

commit 1f3c8804acba841b5573b953f5560d2683d2db0d
Author: Andy Gospodarek <[email-masked]>
Date:   Mon Dec 14 10:48:58 2009 +0000

    bonding: allow arp_ip_targets on separate vlans to use arp validation

frames received on VLANs correctly make their way to the bond's handler,
so we no longer need to wildcard the device.

The oops can be reproduced by:

modprobe bonding

echo active-backup > /sys/class/net/bond0/bonding/mode
echo 100 > /sys/class/net/bond0/bonding/miimon
ifconfig bond0 xxx.xxx.xxx.xxx netmask xxx.xxx.xxx.xxx
echo +eth0 > /sys/class/net/bond0/bonding/slaves
echo +eth1 > /sys/class/net/bond0/bonding/slaves

echo +bond1 > /sys/class/net/bonding_masters
echo balance-alb > /sys/class/net/bond1/bonding/mode
echo 100 > /sys/class/net/bond1/bonding/miimon
ifconfig bond1 xxx.xxx.xxx.xxx netmask xxx.xxx.xxx.xxx
echo +eth2 > /sys/class/net/bond1/bonding/slaves
echo +eth3 > /sys/class/net/bond1/bonding/slaves

Pass some traffic on bond0.  Boom.

[ Tested, behaves as advertised.  I do not believe a test of the bonding
mode is necessary, as there is no race between the packet handler and
the bonding mode changing (the mode can only change when the device is
closed).  Also updated the log message to include the reproduction and
full commit ids.  -J ]
	
Signed-off-by: Greg Edwards <[email-masked]>
Signed-off-by: Jay Vosburgh <[email-masked]>

---

 drivers/net/bonding/bond_alb.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index df48307..8d7dfd2 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -822,7 +822,7 @@ static int rlb_initialize(struct bonding *bond)

 	/*initialize packet type*/
 	pk_type->type = cpu_to_be16(ETH_P_ARP);
-	pk_type->dev = NULL;
+	pk_type->dev = bond->dev;
 	pk_type->func = rlb_arp_recv;

 	/* register to receive ARPs */
-- 
1.7.0.4